Synthesis, antiviral activity, and 3D-QSAR study of novel chalcone derivatives containing malonate and pyridine moieties

Zhiwei Chen; Pei Li; Deyu Hu; Liangrui Dong; Jianke Pan; Liangzhi Luo; Weiying Zhang; Wei Xue; Linhong Jin; Baoan Song

doi:10.1016/j.arabjc.2015.05.003

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Original article

12 (

); 2685-2696

doi:

10.1016/j.arabjc.2015.05.003

Synthesis, antiviral activity, and 3D-QSAR study of novel chalcone derivatives containing malonate and pyridine moieties

Zhiwei Chen, Pei Li, Deyu Hu, Liangrui Dong, Jianke Pan, Liangzhi Luo, Weiying Zhang, Wei Xue, Linhong Jin, Baoan Song^⁎

State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, PR China

⁎Corresponding author. Tel.: +86 851 83620521; fax: +86 851 83622211. songbaoan22@yahoo.com (Baoan Song)

Received: 2015-2-17, Accepted: 2015-5-3, Published: 2015-12-01

Disclaimer:
This article was originally published by Elsevier and was migrated to Scientific Scholar after the change of Publisher.

Peer review under responsibility of King Saud University.

Abstract

Several novel chalcone derivatives containing malonate and pyridine moieties were synthesized, and their structures were confirmed by ¹H nuclear magnetic resonance, ¹³C nuclear magnetic resonance, ¹⁹F nuclear magnetic resonance, infrared, and elemental analyses. Antiviral bioassays revealed that most of the compounds exhibited good antiviral activity against cucumber mosaic virus (CMV) at 500 μg/mL. In particular, compounds 5l and 5n showed significant curative activities against CMV in vivo with 50% effective concentration (EC₅₀) values of 186.2 and 211.5 μg/mL, respectively; these values are even better than that of ningnanmycin (330.5 μg/mL). A 3D quantitative structure–activity relationship study was carried out using the comparative molecular field analysis technique based on curative activities against CMV. Results revealed good predictive ability with cross-validated q² and non-cross-validated r² values of 0.517 and 0.990, respectively.

Keywords

Chalcone derivatives

Malonate moiety

Pyridine moiety

Antiviral activity

Cucumber mosaic virus

3D-QSAR

Show Related Articles from PubMed

TLC: thin layer chromatography
EC₅₀: 50% effective concentration
¹H NMR: ¹H nuclear magnetic resonance
¹³C NMR: ¹³C nuclear magnetic resonance
¹⁹F NMR: ¹⁹F nuclear magnetic resonance
MS: mass spectroscopy
CMV: cucumber mosaic virus
3D-SAR: three-dimensional quantitative structure–activity relationship
CoMFA: comparative molecular field analysis
Nicotiana tabacum L.: N. tabacum L.
Chenopodium amaranticolor: C. amaranticolor
PLS: partial least-squares
ONC: optimal number of components
SEE: standard error of estimate

1 Introduction

Cucumber mosaic virus (CMV), a member of Cucumovirus that affects cucumber and other cucurbits, was first described in detail in 1916 and is known to affect 1200 species in over 100 plant families and cause significant economic losses in a great quantity of vegetable and horticultural crops (Palukaitis, 1992; Abad et al., 2000; Gallitelli, 2000; Stamova and Chetelat, 2000; Sulistyowati et al., 2004; Lin et al., 2010 ). Ningnanmycin, the most successful registered anti-plant viral agent, cannot achieve optimal cure rates for the virus (Chen et al., 2009; Wang et al., 2012; Luo et al., 2013; Ma et al., 2014 ). As such, the development of highly efficient, novel, and environmentally benign agents to control the refractory virus disease is a significant endeavor (Ritzenthaler, 2005; Song et al., 2009).

1,3-Diarylprop-2-en-1-ones, commonly known as chalcones, have received a great deal of interest in the pharmacological chemistry. Compounds with the chalcone backbone are reported to possess a wide range of biological activities, such as nematicide (González and Estévez-Braun, 1998), antifungal (Zhao et al., 2007), antiallergenic (Yoshimura et al., 2009), antimicrobial (Bandgar et al., 2010), anticancer (Vincenzo et al., 2000), antimalarial (Liu et al., 2001), and antifeedant (Thirunarayanan and Vanangamudi, 2014) properties.

Malonates are traditionally regarded as important materials for synthesizing the key intermediates of numerous active substances but rarely found as pharmacophores belonging to the target compounds (Wheeler, 1984; Woo et al., 1989; Ragoussis et al., 2004; Brandau et al., 2006 ). In our previous work, we designed and synthesized a series of β-amino acid ester derivatives containing the malonate moiety with improved antiviral activities against tobacco mosaic virus (TMV) (Xiao et al., 2014). Pyridine derivatives are an important class of bioactive compounds that have a wide spectrum of activities, including antimicrobial (Patel and Patel, 2012), herbicidal (Liu et al., 2008), antitumor (Ahmeda et al., 2009), and insecticidal (Kang et al., 2013) properties.

Using previous findings as a basis, we aimed to introduce malonate and pyridine fragments to the parent chalcone skeleton by Michael addition to build a novel family of bioactive molecules. Bioassay results of most of the resultant compounds revealed moderate to good anti-CMV activity. A 3D quantitative structure–activity relationship (3D-QSAR) study of 22 target compounds was carried out using the comparative molecular field analysis (CoMFA) technique based on their curative activities against CMV, and results revealed good predictive ability. To the best of our knowledge, the present work is the first to report chalcone derivatives containing malonate and pyridine moieties with potent effects against CMV determined through 3D-QSAR analysis.

2 Experimental

2.1

2.1 Materials and methods

¹H nuclear magnetic resonance (¹H NMR), ¹⁹F nuclear magnetic resonance (¹⁹F NMR), and ¹³C nuclear magnetic resonance (¹³C NMR) (solvent CDCl₃) spectral analyses were performed on a JEOL-ECX500 NMR spectrometer operating at 500, 475 and 125 MHz at room temperature with tetramethylsilane as the internal standard. Elemental analysis was performed on an Elementar Vario-III CHN analyzer. Infrared (IR) spectra were recorded on a Bruker VECTOR 22 spectrometer by using KBr disks. Mass spectral studies were conducted on an Agilent 5973 organic mass spectrometer. The melting points of the products were determined by using an XT-4 binocular microscope (Beijing Tech Instrument Co., China) and are reported uncorrected. Analytical thin-layer chromatography was performed on silica gel GF254 (400 mesh). Column chromatographic purification was carried out using silica gel. All reagents and reactants were purchased from commercial suppliers and were either of analytical reagent grade or of chemically pure. All solvents were dried, deoxygenated, and redistilled prior to use.

2.2

2.2 Chemistry

2.2.1

2.2.1 General procedure for synthesizing (E)-3-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-1-(aryl)prop-2-en-1-ones (4a–4k)

As shown in Scheme 1, intermediate 3 was synthesized following a previously reported method (Choudhary and Juyal, 2011). Substituted acetophenone 1 was reacted with p-hydroxy benzaldehyde 2 through Claisen–Schmidt aldol condensation at 20–25 °C to achieve intermediate 3 in good yield. Then, key intermediates 4a–4k were synthesized as shown in Scheme 1 by using a previously described method (Zhao et al., 2007). Intermediate 3 (2.5 mmol), 2-chloro-5-(chloromethyl) pyridine (2.5 mmol), K₂CO₃ (7.5 mmol), and acetone (15 mL) were added to a 25 mL three-neck round-bottom flask fitted with a magnetic stirring bar. The resulting mixture was refluxed at 60 °C for 12 h, poured into ice water (20 mL), and then separated. The aqueous phase was acidified with 10% HCl to pH 6–7 and filtered. The residue was dried and recrystallized from ethanol to obtain the key intermediates 4a–4k. The physical characteristics and IR, ¹H NMR, ¹³C NMR, and elemental data of 4a–4k are provided as supplementary data.

Synthesis of the target compounds 5a–5v.

2.2.2

2.2.2 General procedure for synthesizing dimethyl (ethyl) 2-(1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-oxo-3-(aryl)phlpropyl)malonates (5a–5v)

The target compounds 5a–5v were synthesized as illustrated in Scheme 1. A 25 mL round-bottomed flask equipped with a magnetic stirrer was charged with intermediate 4 (0.3 mmol), dimethyl malonate (or diethyl malonate) (1.5 mmol), CH₃OH (or C₂H₅OH) (8 mL), and KOH (0.3 mmol). The resulting mixture was refluxed and stirred at 70–80 °C for 0.5 h. After pouring into ice water (10 mL), the solution was acidified to pH 6–7 with 10% HCl and then extracted with CH₂Cl₂ (5 mL × 3). The combined organic layer was concentrated under rotary evaporation, and the crude residue was separated through column chromatography on silica gel (ethyl acetate/petroleum ether = 1/5 [v/v]) to obtain the target compounds 5a–5v. The physical characteristics and IR, ¹H NMR, ¹³C NMR, ¹⁹F nuclear magnetic resonance (¹⁹F NMR), mass spectra (MS), and elemental data of target compounds 5a–5v are provided below.

2.2.2.1

2.2.2.1 Dimethyl 2-(1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-oxo-3-phenylpropyl)malonate (5a)

Yield, 77%; white solid; m.p. 89–91 °C; IR (KBr, cm⁻¹): ν 2841–2996 (C—H), 1734 (—O—C⚌O), 1674 (Ar′—C⚌O), 1458–1609 (C⚌C and benzene and Py-ring), 1298 (C—N), 1234 (Ar—C—O), 1157 (CH₃—O—C⚌O), 818 (C—Cl); ¹H NMR (500 MHz, CDCl₃, ppm): δ 8.42 (d, 1H, J = 2.25 Hz, Py-2-H), 7.90 (d, 2H, J = 7.10 Hz, Ar′-2,6-H), 7.71 (dd, 1H, J₁ = 2.35 Hz, J₂ = 2.40 Hz, Py-4-H), 7.54 (t, 1H, J₁ = 7.35 Hz, J₂ = 7.40 Hz, Ar′-4-H), 7.43 (t, 2H, J₁ = 7.85 Hz, J₂ = 7.60 Hz, Ar′-3,5-H), 7.34 (d, 1H, J = 8.25 Hz, Py-5-H), 7.20 (d, 2H, J = 8.75 Hz, Ar-2,6-H), 6.84 (d, 2H, J = 8.65 Hz, Ar-3,5-H), 4.98 (s, 2H, Py—CH₂—), 4.17–4.13 (m, 1H, Ar—CH—), 3.82 (d, 1H, J = 9.35 Hz, —CO₂—CH—), 3.74 (s, 3H, —CO₂—CH₃), 3.54–3.50 (m, 4H, —CO₂—CH₃, —CO—CH—), 3.44 (dd, 1H, J₁ = J₂ = 9.20 Hz, —CO—CH—); ¹³C NMR (125 MHz, CDCl₃, ppm): δ 197.6, 168.7, 168.2, 157.1, 151.1, 148.7, 138.1, 136.7, 133.3, 133.2, 131.5, 129.3, 128.6, 128.1, 124.3, 114.7, 66.6, 57.4, 52.7, 52.5, 42.4, 40.1; MS (ESI) m/z: 504.3 ([M + Na]⁺). Anal. Calcd for C₂₆H₂₄ClNO₆: C, 64.80; H, 5.02; N, 2.91. Found: C, 64.86; H, 5.19; N, 2.98.

2.2.2.2

2.2.2.2 Dimethyl 2-(1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-oxo-3-(o-tolyl)propyl)malonate (5b)

Yield, 68%; white solid; m.p. 79–81 °C; IR (KBr, cm⁻¹): ν 2855–2955 (C—H), 1748 (—O—C⚌O), 1682 (Ar′—C⚌O), 1456–1609 (C⚌C and benzene and Py-ring), 1327 (C—N), 1248 (Ar—C—O), 1157 (CH₃—O—C⚌O), 829 (C—Cl); ¹H NMR (500 MHz, CDCl₃, ppm): δ 8.40 (d, 1H, J = 2.20 Hz, Py-2-H), 7.69 (dd, 1H, J₁ = J₂ = 2.40 Hz, Py-4-H), 7.55 (d, 1H, J = 7.70 Hz, Ar′-6-H), 7.31–7.29 (m, 2H, Ar′-4-H, Py-5-H), 7.21 (t, 1H, J₁ = 7.55 Hz, J₂ = 7.50 Hz, Ar′-5-H), 7.14–7.12 (m, 3H, Ar′-3-H, Ar-2,6-H), 6.83 (d, 2H, J = 8.60 Hz, Ar-3,5-H), 4.98 (s, 2H, Py—CH₂—), 4.07–4.02 (m, 1H, Ar—CH—), 3.78 (d, 1H, J = 9.65 Hz, —CO₂—CH—), 3.73 (s, 3H, —CO₂—CH₃), 3.50–3.45 (m, 4H, —CO₂—CH₃, —CO—CH—), 3.29 (dd, 1H, J₁ = J₂ = 9.90 Hz, —CO—CH—), 2.16 (s, 3H, Ar′—CH₃); ¹³C NMR (125 MHz, CDCl₃, ppm): δ 202.0, 168.7, 168.1, 157.2, 151.0, 148.8, 138.2, 138.0, 137.9, 133.1, 131.8, 131.7, 131.2, 129.5, 128.3, 125.7, 124.3, 114.8, 66.7, 57.5, 52.7, 52.4, 45.5, 40.5, 20.7; MS (ESI) m/z: 518.3 ([M + Na]⁺). Anal. Calcd. for C₂₇H₂₆ClNO₆: C, 65.39; H, 5.28; N, 2.82. Found: C, 65.36; H, 5.40; N, 2.89.

2.2.2.3

2.2.2.3 Dimethyl 2-(1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-oxo-3-(m-tolyl)propyl)malonate (5c)

Yield, 44%; white solid; m.p. 75–77 °C; IR (KBr, cm⁻¹): ν 2849–2955 (C—H), 1734 (—O—C⚌O), 1684 (Ar′—C⚌O), 1458–1616 (C⚌C and benzene and Py-ring), 1289 (C—N), 1242 (Ar—C—O), 1152 (CH₃—O—C⚌O), 827.5 (C—Cl); ¹H NMR (500 MHz, CDCl₃, ppm): δ 8.41 (d, 1H, J = 1.60 Hz, Py-2-H), 7.71–7.70 (m, 3H, Py-4-H, Ar′-2,6-H), 7.35–7.28 (m, 3H, Ar′-4,5-H, Py-5-H), 7.21 (d, 2H, J = 8.15 Hz, Ar-2,6-H), 6.84 (d, 2H, J = 8.20 Hz, Ar-3,5-H), 4.97 (s, 2H, Py—CH₂—), 4.18–4.14 (m, 1H, Ar—CH—), 3.84 (d, 1H, J = 8.50 Hz, —CO₂—CH—), 3.73 (s, 3H, —CO₂—CH₃), 3.55–3.42 (m, 5H, —CO₂—CH₃, —CO—CH—), 2.37 (s, 3H, Ar′—CH₃); ¹³C NMR (125 MHz, CDCl₃, ppm): δ 197.8, 168.8, 168.3, 157.2, 151.1, 148.8, 138.4, 138.3, 136.8, 134.0, 133.5, 131.7, 129.4, 128.7, 128.6, 125.4, 124.3, 114.7, 66.7, 57.5, 52.8, 52.6, 42.6, 40.1, 21.4; MS (ESI) m/z: 518.3 ([M + Na]⁺). Anal. Calcd for C₂₇H₂₆ClNO₆: C, 65.39; H, 5.28; N, 2.82. Found: C, 65.28; H, 5.52; N, 2.96.

2.2.2.4

2.2.2.4 Dimethyl 2-(1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-oxo-3-(p-tolyl)propyl)malonate (5d)

Yield, 44%; white solid; m.p. 87–89 °C; IR (KBr, cm⁻¹): ν 2886–3032 (C—H), 1749 (—O—C⚌O), 1670 (Ar′—C⚌O), 1458–1609 (C⚌C and benzene and Py-ring), 1271 (C—N), 1232 (Ar—C—O), 1159 (CH₃—O—C⚌O), 822 (C—Cl); ¹H NMR (500 MHz, CDCl₃, ppm): δ 8.42 (d, 1H, J = 2.25 Hz, Py-2-H), 7.80 (d, 2H, J = 8.15 Hz, Ar′-2,6-H), 7.72 (dd, 1H, J₁ = J₂ = 2.40 Hz, J = 2.35 Hz, Py-4-H), 7.35 (d, 1H, J = 8.15 Hz, Py-5-H), 7.23–7.19 (m, 4H, Ar-2,6-H, Ar′-3,5-H), 6.83 (d, 2H, J = 8.60 Hz, Ar-3,5-H), 4.98 (s, 2H, Py—CH₂—), 4.16–4.12 (m, 1H, Ar—CH—), 3.82 (d, 1H, J = 9.40 Hz, —CO₂—CH—), 3.73 (s, 3H, —CO₂—CH₃), 3.52–3.46 (m, 4H, —CO₂—CH₃, —CO—CH—), 3.40 (dd, 1H, J₁ = 9.20 Hz, J₂ = 9.15 Hz, —CO—CH—), 2.39 (s, 3H, Ar′—CH₃); ¹³C NMR (125 MHz, CDCl₃, ppm): δ 197.8, 168.8, 168.3, 157.2, 151.1, 148.8, 138.4, 138.3, 136.8, 134.0, 133.5, 131.7, 129.4, 128.7, 128.6, 125.4, 124.3, 114.7, 66.7, 57.5, 52.8, 52.6, 42.6, 40.1, 21.4; MS (ESI) m/z: 518.3 ([M + Na]⁺). Anal. Calcd for C₂₇H₂₆ClNO₆: C, 65.39; H, 5.28; N, 2.82. Found: C, 65.17; H, 5.57; N, 2.90.

2.2.2.5

2.2.2.5 Dimethyl 2-(3-(2-chlorophenyl)-1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-oxopropyl)malonate (5e)

Yield, 70%; white solid; m.p. 97–99 °C; IR (KBr, cm⁻¹): ν 2849–3065 (C—H), 1721 (—O—C⚌O), 1701 (Ar′—C⚌O), 1458–1611 (C⚌C and benzene and Py-ring), 1319 (C—N), 1258 (Ar—C—O), 1161 (CH₃—O—C⚌O), 820 (C—Cl); ¹H NMR (500 MHz, CDCl₃, ppm): δ 8.43 (d, 1H, J = 2.15 Hz, Py-2-H), 7.73 (dd, 1H, J₁ = 2.35 Hz, J₂ = 2.30 Hz, Py-4-H), 7.36–7.32 (m, 3H, Ar′-4,6-H, Py-5-H), 7.26–7.21 (m, 1H, Ar′-5-H), 7.19 (d, 1H, J = 7.05 Hz, Ar′-3-H), 7.16 (d, 2H, J = 8.65 Hz, Ar-2,6-H), 6.84 (d, 2H, J = 8.65 Hz, Ar-3,5-H), 5.01 (s, 2H, Py—CH₂—), 4.07–4.02 (m, 1H, Ar—CH—), 3.78–3.75 (m, 4H, —CO₂—CH—, —CO₂—CH₃), 3.53–3.48 (m, 4H, —CO₂—CH₃, —CO—CH—), 3.42 (dd, 1H, J₁ = 9.55 Hz, J₂ = 9.65 Hz, —CO—CH—); ¹³C NMR (125 MHz, CDCl₃, ppm): δ 200.7, 168.5, 168.0, 157.2, 151.1, 148.7, 139.0, 138.1, 132.8, 131.7, 131.5, 130.7, 130.4, 129.5, 129.0, 126.8, 124.3, 114.7, 66.6, 57.3, 52.8, 52.5, 46.5, 40.1; MS (ESI) m/z: 538.3 ([M + Na]⁺). Anal. Calcd for C₂₆H₂₃Cl₂NO₆: C, 60.48; H, 4.49; N, 2.71. Found: C, 60.55; H, 4.64; N, 2.83.

2.2.2.6

2.2.2.6 Dimethyl 2-(3-(3-chlorophenyl)-1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-oxopropyl)malonae (5f)

Yield, 50%; white solid; m.p. 77–79 °C; IR (KBr, cm⁻¹): ν 2849–3065 (C—H), 1734 (—O—C⚌O), 1684 (Ar′—C⚌O), 1458–1609 (C⚌C and benzene and Py-ring), 1311 (C—N), 1244 (Ar—C—O), 1155 (CH₃—O—C⚌O), 831 (C—Cl); ¹H NMR (500 MHz, CDCl₃, ppm): δ 8.41 (d, 1H, J = 2.15 Hz, Py-2-H), 7.84 (s, 1H, Ar′-2-H), 7.79 (d, 1H, J = 7.90 Hz, Ar′-6-H), 7.72 (dd, 1H, J₁ = 2.30 Hz, J₂ = 2.40 Hz, Py-4-H), 7.51–7.49 (m, 1H, Ar′-4-H), 7.39–7.33 (m, 2H, Ar′-5-H, Py-5-H), 7.20 (d, 2H, J = 8.60 Hz, Ar-2,6-H), 6.85 (d, 2H, J = 8.60 Hz, Ar-3,5-H), 4.99 (s, 2H, Py—CH₂—), 4.15–4.10 (m, 1H, Ar—CH—), 3.82 (d, 1H, J = 9.45 Hz, —CO₂—CH—), 3.74 (s, 3H, —CO₂—CH₃), 3.53–3.48 (m, 4H, —CO₂—CH₃, —CO—CH—), 3.41 (dd, 1H, J₁ = 9.25 Hz, J₂ = 9.20 Hz, —CO—CH—); ¹³C NMR (125 MHz, CDCl₃, ppm): δ 196.5, 168.8, 168.2, 157.3, 151.0, 148.7, 138.4, 138.2, 134.9, 133.2, 133.1, 131.7, 130.7, 130.1, 129.4, 128.2, 126.3, 124.4, 114.8, 66.6, 57.3, 52.9, 52.6, 42.7, 40.1; MS (ESI) m/z: 538.3 ([M + Na]⁺). Anal. Calcd for C₂₆H₂₃Cl₂NO₆: C, 60.48; H, 4.49; N, 2.71. Found: C, 60.58; H, 4.72; N, 2.75.

2.2.2.7

2.2.2.7 Dimethyl 2-(3-(4-chlorophenyl)-1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-oxopropyl)malonate (5g)

Yield, 57%; white solid; m.p. 103–105 °C; IR (KBr, cm⁻¹): ν 2887–3088 (C—H), 1734 (—O—C⚌O), 1684 (Ar′—C⚌O), 1458–1616 (C⚌C and benzene and Py-ring), 1308 (C—N), 1248 (Ar—C—O), 1159 (CH₃—O—C⚌O), 833 (C—Cl); ¹H NMR (500 MHz, CDCl₃, ppm): δ 8.42 (d, 1H, J = 2.35 Hz, Py-2-H), 7.84 (d, 2H, J = 8.55 Hz, Ar′-2,6-H), 7.71 (dd, 1H, J₁ = 2.55 Hz, J₂ = 2.40 Hz, Py-4-H), 7.41 (d, 2H, J = 8.60 Hz, Ar′-3,5-H), 7.35 (d, 1H, J = 8.15 Hz, Py-5-H), 7.18 (d, 2H, J = 8.65 Hz, Ar-2,6-H), 6.84 (d, 2H, J = 8.65 Hz, Ar-3,5-H), 4.98 (s, 2H, Py—CH₂—), 4.13–4.09 (m, 1H, Ar—CH—), 3.80 (d, 1H, J = 9.35 Hz, —CO₂—CH—), 3.74 (s, 3H, —CO₂—CH₃), 3.52–3.48 (m, 4H, —CO₂—CH₃, —CO—CH—), 3.38 (dd, 1H, J₁ = 9.30 Hz, J₂ = 9.35 Hz, —CO—CH—); ¹³C NMR (125 MHz, CDCl₃, ppm): δ 196.4, 168.7, 168.1, 157.2, 151.2, 148.7, 139.6, 138.1, 135.0, 133.0, 131.5, 129.5, 129.3, 128.9, 124.3, 114.7, 66.6, 57.3, 52.7, 52.5, 42.4, 40.1; MS (ESI) m/z: 538.3 ([M + Na]⁺). Anal. Calcd for C₂₆H₂₃Cl₂NO₆: C, 60.48; H, 4.49; N, 2.71. Found: C, 60.53; H, 4.69; N, 2.86.

2.2.2.8

2.2.2.8 Dimethyl 2-(1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-(2,4-dichlorophenyl)-3-oxopropyl)malonate (5h)

Yield, 51%; white solid; m.p. 109–111 °C; IR (KBr, cm⁻¹): ν 2864–3069 (C—H), 1741 (—O—C⚌O), 1699 (Ar′—C⚌O), 1456–1609 (C⚌C and benzene and Py-ring), 1280 (C—N), 1252 (Ar—C—O), 1159 (CH₃—O—C⚌O), 831 (C—Cl); ¹H NMR (500 MHz, CDCl₃, ppm): δ 8.43 (d, 1H, J = 2.30 Hz, Py-2-H), 7.73 (dd, 1H, J₁ = J₂ = 2.40 Hz, Py-4-H), 7.38 (d, 1H, J = 1.85 Hz, Ar′-6-H), 7.36 (d, 1H, J = 8.15 Hz, Py-5-H), 7.23 (dd, 1H, J₁ = 1.80 Hz, J₂ = 1.95 Hz, Ar′-3-H), 7.17 (d, 1H, J = 8.25 Hz, Ar′-5-H), 7.14 (d, 2H, J = 8.70 Hz, Ar-2,6-H), 6.84 (d, 2H, J = 8.70 Hz, Ar-3,5-H), 5.00 (s, 2H, Py—CH₂—), 4.04–4.00 (m, 1H, Ar—CH—), 3.76–3.74 (m, 4H, —CO₂—CH—, —CO₂—CH₃), 3.52–3.47 (m, 4H, —CO₂—CH₃, —CO—CH—), 3.39 (dd, 1H, J₁ = 9.70 Hz, J₂ = 9.60 Hz, —CO—CH—); ¹³C NMR (125 MHz, CDCl₃, ppm): δ 199.5, 168.5, 168.0, 148.7, 138.1, 132.7, 130.3, 129.5, 127.2, 124.3, 114.8, 66.7, 57.2, 52.8, 52.5, 46.5, 40.2; MS (ESI) m/z: 572.2 ([M + Na]⁺). Anal. Calcd for C₂₆H₂₂Cl₃NO₆: C, 56.69; H, 4.03; N, 2.54. Found: C, 56.55; H, 4.11; N, 2.82.

2.2.2.9

2.2.2.9 Dimethyl 2-(1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-(4-ethoxyphenyl)-3-oxopropyl)malonate (5i)

Yield, 46%; white solid; m.p. 93–95 °C; IR (KBr, cm⁻¹): ν 2891–2990 (C—H), 1732 (—O—C⚌O), 1667 (Ar′—C⚌O), 1458–1603 (C⚌C and benzene and Py-ring), 1308 (C—N), 1234 (Ar—C—O), 1179 (—CH₂—O—Ar′), 1157 (CH₃—O—C⚌O), 831 (C—Cl); ¹H NMR (500 MHz, CDCl₃, ppm): δ 8.42 (d, 1H, J = 2.25 Hz, Py-2-H), 7.88 (d, 2H, J = 8.95 Hz, Ar′-2,6-H), 7.71 (dd, 1H, J₁ = 2.50 Hz, J₂ = 2.40 Hz, Py-4-H), 7.34 (d, 1H, J = 8.25 Hz, Py-5-H), 7.19 (d, 2H, J = 8.70 Hz, Ar-2,6-H), 6.88 (d, 2H, J = 8.90 Hz, Ar′-3,5-H), 6.83 (d, 2H, J = 8.70 Hz, Ar-3,5-H), 4.98 (s, 2H, Py—CH₂—), 4.16–4.05 (m, 3H, Ar—CH—, Ar′—OCH₂—), 3.81 (d, 1H, J = 9.40 Hz, —CO₂—CH—), 3.73 (s, 3H, —CO₂—CH₃), 3.52 (s, 3H, —CO₂—CH₃), 3.45 (dd, 1H, J₁ = 4.70 Hz, J₂ = 4.65 Hz, —CO—CH—), 3.36 (dd, 1H, J₁ = J₂ = 9.25 Hz, —CO—CH—), 1.43 (t, 3H, J₁ = J₂ = 7.05 Hz, Ar′—OCH₂—CH₃); ¹³C NMR (125 MHz, CDCl₃, ppm): δ 196.0, 168.8, 168.2, 162.9, 157.1, 153.7, 148.7, 138.1, 133.4, 131.5, 130.4, 129.6, 129.3, 124.3, 114.6, 114.1, 66.6, 63.7, 57.4, 52.7, 52.5, 42.1, 40.3, 14.7; MS (ESI) m/z: 548.3 ([M + Na]⁺). Anal. Calcd for C₂₈H₂₈ClNO₇: C, 63.94; H, 5.37; N, 2.66. Found: C, 63.92; H, 5.46; N, 2.78.

2.2.2.10

2.2.2.10 Dimethyl 2-(1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-(4-fluorophenyl)-3-oxopropyl)malonate (5j)

Yield, 65%; white solid; m.p. 74–76 °C; IR (KBr, cm⁻¹): ν 2849–3067 (C—H), 1734 (—O—C⚌O), 1684 (Ar′—C⚌O), 1458–1616 (C⚌C and benzene and Py-ring), 1319 (C—N), 1260 (C—F), 1227 (Ar—C—O), 1155 (CH₃—O—C⚌O), 831 (C—Cl); ¹H NMR (500 MHz, CDCl₃, ppm): δ 8.42 (d, 1H, J = 2.20 Hz, Py-2-H), 7.95–7.92 (m, 2H, Ar′-2,6-H), 7.71 (dd, 1H, J₁ = 2.40 Hz, J₂ = 2.45 Hz, Py-4-H), 7.34 (d, 1H, J = 8.15 Hz, Py-5-H), 7.18 (d, 2H, J = 8.70 Hz, Ar-2,6-H), 7.10 (t, 2H, J₁ = 8.55 Hz, J₂ = 8.60 Hz, Ar′-3,5-H), 6.84 (d, 2H, J = 8.65 Hz, Ar-3,5-H), 4.98 (s, 2H, Py—CH₂—), 4.14–4.10 (m, 1H, Ar—CH—), 3.81 (d, 1H, J = 9.35 Hz, —CO₂—CH—), 3.74 (s, 3H, —CO₂—CH₃), 3.53–3.49 (m, 4H, —CO₂—CH₃, —CO—CH—), 3.39 (dd, 1H, J₁ = J₂ = 9.40 Hz, —CO—CH—); ¹³C NMR (125 MHz, CDCl₃, ppm): δ 196.1, 168.8, 168.2, 166.8, 164.8, 157.3, 151.2, 148.8, 138.2, 133.2, 131.6, 130.9, 130.8, 129.4, 124.4, 115.9, 115.7, 114.8, 66.7, 57.4, 52.8, 52.6, 42.5, 40.3; ¹⁹F NMR (470 MHz, CDCl₃, ppm): δ −104.91; MS (ESI) m/z: 522.3 ([M + Na]⁺). Anal. Calcd for C₂₆H₂₃ClFNO₆: C, 62.47; H, 4.64; N, 2.80. Found: C, 62.09; H, 4.83; N, 2.91.

2.2.2.11

2.2.2.11 Dimethyl 2-(1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-(4-isopropylphenyl)-3-oxopropyl)malonate (5k)

Yield, 52%; white solid; m.p. 61–63 °C; IR (KBr, cm⁻¹): ν 2874–3046 (C—H), 1748 (—O—C⚌O), 1674 (Ar′—C⚌O), 1458–1609 (C⚌C and benzene and Py-ring), 1314 (C—N), 1262 (Ar—C—O), 1150 (CH₃—O—C⚌O), 830 (C—Cl); ¹H NMR (500 MHz, CDCl₃, ppm): δ 8.42 (d, 1H, J = 2.25 Hz, Py-2-H), 7.84 (d, 2H, J = 8.35 Hz, Ar′-2,6-H), 7.72 (dd, 1H, J₁ = 2.55 Hz, J₂ = 2.40 Hz, Py-4-H), 7.34 (d, 1H, J = 8.25 Hz, Py-5-H), 7.28 (d, 2H, J = 8.25 Hz, Ar-2,6-H), 7.20 (d, 2H, J = 8.70 Hz, Ar′-3,5-H), 6.83 (d, 2H, J = 8.75 Hz, Ar-3,5-H), 4.98 (s, 2H, Py—CH₂—), 4.17–4.12 (m, 1H, Ar—CH—), 3.82 (d, 1H, J = 9.55 Hz, —CO₂—CH—), 3.73 (s, 3H, —CO₂—CH₃), 3.52 (s, 3H, —CO₂—CH₃), 3.48 (dd, 1H, J₁ = 4.85 Hz, J₂ = 4.80 Hz, —CO—CH—), 3.41 (dd, 1H, J₁ = J₂ = 9.15 Hz, —CO—CH—), 2.99–2.90 (m, 1H, Ar′—CH—), 1.25 (d, 6H, J = 6.90 Hz, Ar′—CH—(CH₃)₂); ¹³C NMR (125 MHz, CDCl₃, ppm): δ 197.1, 168.7, 168.2, 157.1, 154.7, 151.1, 148.7, 138.2, 134.6, 133.4, 131.5, 129.3, 128.3, 126.7, 124.3, 114.6, 66.6, 57.4, 52.7, 52.5, 42.3, 40.1, 34.2, 23.7; MS (ESI) m/z: 546.3 ([M + Na]⁺). Anal. Calcd for C₂₉H₃₀ClNO₆: C, 66.47; H, 5.77; N, 2.67. Found: C, 66.56; H, 5.77; N, 2.78.

2.2.2.12

2.2.2.12 Diethyl 2-(1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-oxo-3-phenylpropyl)malonate (5l)

Yield, 71%; white solid; m.p. 82–84 °C; IR (KBr, cm⁻¹): ν 2874–3065 (C—H), 1740 (—O—C⚌O), 1676 (Ar′—C⚌O), 1458–1616 (C⚌C and benzene and Py-ring), 1292 (C—N), 1262 (Ar—C—O), 1150 (—CH₂—O—C⚌O), 824 (C—Cl); ¹H NMR (500 MHz, CDCl₃, ppm): δ 8.41 (d, 1H, J = 2.15 Hz, Py-2-H), 7.90 (d, 2H, J = 7.75 Hz, Ar′-2,6-H), 7.72 (dd, 1H, J₁ = 2.40 Hz, J₂ = 2.30 Hz, Py-4-H), 7.54 (t, 1H, J₁ = 7.35 Hz, J₂ = 7.45 Hz, Ar′-4-H), 7.43 (t, 2H, J₁ = 7.65 Hz, J₂ = 7.70 Hz, Ar′-3,5-H), 7.34 (d, 1H, J = 8.20 Hz, Py-5-H), 7.20 (d, 2H, J = 8.60 Hz, Ar-2,6-H), 6.83 (d, 2H, J = 8.60 Hz, Ar-3,5-H), 4.98 (s, 2H, Py—CH₂—), 4.26–4.17 (m, 2H, —CO₂—CH₂—), 4.16–4.11 (m, 1H, Ar—CH—), 3.97 (q, 2H, —CO₂—CH₂—), 3.78 (d, 1H, J = 9.75 Hz, —CO₂—CH—), 3.52 (dd, 1H, J₁ = 4.30 Hz, J₂ = 4.20 Hz, —CO—CH—), 3.41 (dd, 1H, J₁ = 9.60 Hz, J₂ = 9.55 Hz, —CO—CH—), 1.25 (t, 3H, J₁ = 7.25 Hz, J₂ = 7.00 Hz, —CO₂—CH₂—CH₃), 1.03 (t, 3H, J₁ = 7.25 Hz, J₂ = 7.00 Hz, —CO₂—CH₂—CH₃); ¹³C NMR (125 MHz, CDCl₃, ppm): δ 197.6, 168.3, 167.7, 157.1, 151.1, 148.7, 138.1, 136.7, 133.3, 133.1, 131.5, 129.5, 128.6, 128.1, 124.2, 114.6 66.6, 61.7, 61.4, 57.7, 42.8, 40.1, 14.1, 13.8; MS (ESI) m/z: 532.4 ([M + Na]⁺). Anal. Calcd for C₂₈H₂₈ClNO₆: C, 65.94; H, 5.53; N, 2.75. Found: C, 65.87; H, 5.93; N, 2.81.

2.2.2.13

2.2.2.13 Diethyl 2-(1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-oxo-3-(o-tolyl)propyl)malonate (5m)

Yield, 50%; white solid; m.p. 52–54 °C; IR (KBr, cm⁻¹) ν: 2849–3065 (C—H), 1734 (—O—C⚌O), 1684 (Ar′—C⚌O), 1458–1616 (C⚌C and benzene and Py-ring), 1319 (C—N), 1244 (Ar—C—O), 1179 (—CH₂—O—C⚌O), 828 (C—Cl); ¹H NMR (500 MHz, CDCl₃, ppm): δ 8.41 (d, 1H, J = 2.25 Hz, Py-2-H), 7.70 (dd, 1H, J₁ = J₂ = 2.40 Hz, Py-4-H), 7.54 (d, 1H, J = 7.80 Hz, Ar′-6-H), 7.33–7.30 (m, 2H, Ar′-4-H, Py-5-H), 7.22 (t, 1H, J₁ = 7.55 Hz, J₂ = 7.45 Hz, Ar′-5-H), 7.15–7.12 (m, 3H, Ar′-3-H, Ar-2,6-H), 6.82 (d, 2H, J = 8.65 Hz, Ar-3,5-H), 4.98 (s, 2H, Py—CH₂—), 4.26–4.17 (m, 2H, —CO₂—CH₂—), 4.05–4.00 (m, 1H, Ar—CH—), 3.95 (q, 2H, —CO₂—CH₂—), 3.73 (d, 1H, J = 9.90 Hz, —CO₂—CH—), 3.48 (dd, 1H, J₁ = 4.35 Hz, J₂ = 4.30 Hz, —CO—CH—), 3.26 (dd, 1H, J₁ = J₂ = 10.20 Hz, —CO—CH—), 2.15 (s, 3H, Ar′—CH₃), 1.26 (t, 3H, J₁ = 7.15 Hz, J₂ = 7.10 Hz, —CO₂—CH₂—CH₃), 1.01 (t, 3H, J₁ = 7.15 Hz, J₂ = 7.10 Hz, —CO₂—CH₂—CH₃); ¹³C NMR (125 MHz, CDCl₃, ppm): δ 202.1, 168.3, 167.7, 157.2, 151.1, 148.8, 138.2, 138.0, 137.9, 133.1, 131.8, 131.7, 131.2, 129.7, 128.3, 125.7, 124.3, 114.8, 66.7, 61.7, 61.4, 57.8, 45.8, 40.6, 20.7, 14.1, 13.9; MS (ESI) m/z: 546.4 ([M + Na]⁺). Anal. Calcd for C₂₉H₃₀ClNO₆: C, 66.47; H, 5.77; N, 2.67. Found: C, 66.39; H, 6.08; N, 2.83.

2.2.2.14

2.2.2.14 Diethyl 2-(1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-oxo-3-(m-tolyl)propyl)malonate (5n)

Yield, 52%; white solid; m.p. 61–63 °C; IR (KBr, cm⁻¹): ν 2928–3065 (C—H), 1740 (—O—C⚌O), 1674 (Ar′—C⚌O), 1458–1609 (C⚌C and benzene and Py-ring), 1265 (C—N), 1242 (Ar—C—O), 1150 (—CH₂—O—C⚌O), 822 (C—Cl); ¹H NMR (500 MHz, CDCl₃, ppm): δ 8.40 (d, 1H, J = 2.05 Hz, Py-2-H), 7.71–7.70 (m, 3H, Py-4-H, Ar′-2,6-H), 7.34–7.28 (m, 3H, Ar′-4,5-H, Py-5-H), 7.22 (d, 2H, J = 8.60 Hz, Ar-2,6-H), 6.83 (d, 2H, J = 8.70 Hz, Ar-3,5-H), 4.97 (s, 2H, Py—CH₂—), 4.26–4.13 (m, 3H, —CO₂—CH₂—, Ar—CH—), 3.97 (q, 2H, —CO₂—CH₂—), 3.80 (d, 1H, J = 9.75 Hz, —CO₂—CH—), 3.50 (dd, 1H, J₁ = 4.45 Hz, J₂ = 4.35 Hz, —CO—CH—), 3.43 (dd, 1H, J₁ = J₂ = 9.35 Hz, —CO—CH—), 2.36 (s, 3H, Ar′—CH₃), 1.25 (t, 3H, J₁ = 7.15 Hz, J₂ = 7.10 Hz, —CO₂—CH₂—CH₃), 1.03 (t, 3H, J₁ = 7.25 Hz, J₂ = 7.00 Hz, —CO₂—CH₂—CH₃); ¹³C NMR (125 MHz, CDCl₃, ppm): δ 197.8, 168.4, 167.9, 157.1, 151.1, 148.8, 138.4, 138.2, 136.8, 134.0, 133.6, 131.7, 129.6, 128.7, 128.5, 125.4, 124.3, 114.7, 66.6, 61.8, 61.4, 57.7, 42.9, 40.1, 21.4, 14.1, 13.9; MS (ESI) m/z: 546.4 ([M + Na]⁺). Anal. Calcd for C₂₉H₃₀ClNO₆: C, 66.47; H, 5.77; N, 2.67. Found: C, 66.26; H, 6.10; N, 2.72.

2.2.2.15

2.2.2.15 Diethyl 2-(1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-oxo-3-(p-tolyl)propyl)malonate (5o)

Yield, 44%; white solid; m.p. 87–89 °C; IR (KBr, cm⁻¹): ν 2851–3055 (C—H), 1734 (—O—C⚌O), 1684 (Ar′—C⚌O), 1458–1609 (C⚌C and benzene and Py-ring), 1289 (C—N), 1244 (Ar—C—O), 1179 (—CH₂—O—C⚌O), 829 (C—Cl); ¹H NMR (500 MHz, CDCl₃, ppm): δ 8.38 (d, 1H, J = 2.20 Hz, Py-2-H), 7.79 (d, 2H, J = 8.15 Hz, Ar′-2,6-H), 7.68 (dd, 1H, J₁ = J₂ = 2.35 Hz, Py-4-H), 7.29 (d, 1H, J = 8.15 Hz, Py-5-H), 7.21–7.20 (m, 4H, Ar-2,6-H, Ar′-3,5-H), 6.82 (d, 2H, J = 8.60 Hz, Ar-3,5-H), 4.95 (s, 2H, Py—CH₂—), 4.25–4.12 (m, 3H, —CO₂—CH₂—, Ar—CH—), 3.95 (q, 2H, —CO₂—CH₂—), 3.80 (d, 1H, J = 9.75 Hz, —CO₂—CH—), 3.49 (dd, 1H, J₁ = J₂ = 4.40 Hz, —CO—CH—), 3.39 (dd, 1H, J₁ = J₂ = 9.50 Hz, —CO—CH—), 2.36 (s, 3H, Ar′—CH₃), 1.24 (t, 3H, J₁ = 7.05 Hz, J₂ = 7.15 Hz, —CO₂—CH₂—CH₃), 1.02 (t, 3H, J₁ = 7.15 Hz, J₂ = 7.05 Hz, —CO₂—CH₂—CH₃); ¹³C NMR (125 MHz, CDCl₃, ppm): δ 197.3, 168.4, 167.8, 157.2, 151.0, 148.7, 143.9, 138.2, 134.4, 133.6, 131.8, 129.6, 129.3, 128.3, 124.2, 114.7, 66.7, 61.7, 61.4, 57.8, 42.7, 40.3, 21.6, 14.1, 13.9; MS (ESI) m/z: 546.4 ([M + Na]⁺). Anal. Calcd for C₂₉H₃₀ClNO₆: C, 66.47; H, 5.77; N, 2.67. Found: C, 66.18; H, 5.84; N, 2.74.

2.2.2.16

2.2.2.16 Diethyl 2-(3-(2-chlorophenyl)-1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-oxopropyl)malonate (5p)

Yield, 60%; white solid; m.p. 63–65 °C; IR (KBr, cm⁻¹): ν 2911–3050 (C—H), 1726 (—O—C⚌O), 1680 (Ar′—C⚌O), 1458–1609 (C⚌C and benzene and Py-ring), 1294 (C—N), 1236 (Ar—C—O), 1155 (–CH₂–O—C⚌O), 829 (C—Cl); ¹H NMR (500 MHz, CDCl₃, ppm): δ 8.43 (d, 1H, J = 2.15 Hz, Py-2-H), 7.73 (dd, 1H, J₁ = 2.30 Hz, J₂ = 2.35 Hz, Py-4-H), 7.36–7.31 (m, 3H, Ar′-4,6-H, Py-5-H), 7.24–7.21 (m, 1H, Ar′-5-H), 7.18–7.15 (m, 3H, Ar′-3-H, Ar-2,6-H), 6.83 (d, 2H, J = 8.60 Hz, Ar-3,5-H), 5.01 (s, 2H, Py—CH₂–), 4.24–4.18 (m, 2H, —CO₂—CH₂—), 4.06–4.01 (m, 1H, Ar—CH—), 3.96 (q, 2H, —CO₂—CH₂—), 3.72 (d, 1H, J = 9.85 Hz, —CO₂—CH—), 3.50 (dd, 1H, J₁ = 4.45 Hz, J₂ = 4.40 Hz, —CO—CH—), 3.41 (dd, 1H, J₁ = J₂ = 9.90 Hz, —CO—CH—), 1.26 (t, 3H, J₁ = 7.15 Hz, J₂ = 7.05 Hz, —CO₂—CH₂—CH₃), 1.03 (t, 3H, J₁ = 7.15 Hz, J₂ = 7.10 Hz, —CO₂—CH₂—CH₃); ¹³C NMR (125 MHz, CDCl₃, ppm): δ 200.9, 168.2, 167.7, 157.2, 151.2, 148.8, 139.2, 138.2, 133.0, 131.8, 131.6, 130.8, 130.5, 129.8, 129.0, 126.9, 124.3, 114.7, 66.7, 61.8, 61.5, 57.7, 46.9, 40.2, 14.2, 13.9; MS (ESI) m/z: 566.4 ([M + Na]⁺). Anal. Calcd for C₂₈H₂₇Cl₂NO₆: C, 61.77; H, 5.00; N, 2.57. Found: C, 61.36; H, 5.36; N, 2.69.

2.2.2.17

2.2.2.17 Diethyl 2-(3-(3-chlorophenyl)-1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-oxopropyl)malonate (5q)

Yield, 53%; white solid; m.p. 59–61 °C; IR (KBr, cm⁻¹): ν 2905–3065 (C—H), 1740 (—O—C⚌O), 1684 (Ar′—C⚌O), 1458–1609 (C⚌C and benzene and Py-ring), 1294 (C—N), 1256 (Ar—C—O), 1150 (—CH₂—O—C⚌O), 824 (C—Cl); ¹H NMR (500 MHz, CDCl₃, ppm): δ 8.42 (d, 1H, J = 2.20 Hz, Py-2-H), 7.84 (t, 1H, J₁ = 1.65 Hz, J₂ = 1.70 Hz, Ar′-2-H), 7.79 (d, 1H, J = 7.90 Hz, Ar′-6-H), 7.71 (dd, 1H, J₁ = 2.40 Hz, J₂ = 2.35 Hz, Py-4-H), 7.52–7.50 (m, 1H, Ar′-4-H), 7.39–7.34 (m, 2H, Ar′-5-H, Py-5-H), 7.19 (d, 2H, J = 8.65 Hz, Ar-2,6-H), 6.83 (d, 2H, J = 8.60 Hz, Ar-3,5-H), 4.99 (s, 2H, Py—CH₂—), 4.25–4.17 (m, 2H, —CO₂—CH₂—), 4.13–4.09 (m, 1H, Ar—CH—), 3.97 (q, 2H, —CO₂—CH₂—), 3.77 (d, 1H, J = 9.75 Hz, —CO₂—CH—), 3.50 (dd, 1H, J₁ = 4.25 Hz, J₂ = 4.30 Hz, —CO—CH—), 3.38 (dd, 1H, J₁ = 9.55 Hz, J₂ = 9.45 Hz, —CO—CH—), 1.26 (t, 3H, J₁ = 7.25 Hz, J₂ = 7.00 Hz, —CO₂—CH₂—CH₃), 1.04 (t, 3H, J₁ = J₂ = 7.10 Hz, —CO₂—CH₂—CH₃); ¹³C NMR (125 MHz, CDCl₃, ppm): δ 196.5, 168.4, 167.8, 157.2, 151.0, 148.7, 138.3, 138.3, 134.9, 133.2, 133.1, 131.7, 130.1, 129.5, 128.2, 126.3, 124.4, 114.7, 66.6, 61.9, 61.5, 57.6, 43.0, 40.1, 14.1, 13.9; MS (ESI) m/z: 566.3 ([M + Na]⁺). Anal. Calcd for C₂₈H₂₇Cl₂NO₆: C, 61.77; H, 5.00; N, 2.57. Found: C, 61.39; H, 5.16; N, 2.73.

2.2.2.18

2.2.2.18 Diethyl 2-(3-(4-chlorophenyl)-1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-oxopropyl)malonate (5r)

Yield, 50%; white solid; m.p. 67–69 °C; IR (KBr, cm⁻¹): ν 2911–3050 (C—H), 1726 (—O—C⚌O), 1680 (Ar′—C⚌O), 1458–1609 (C⚌C and benzene and Py-ring), 1294 (C—N), 1236 (Ar—C—O), 1159 (—CH₂—O—C⚌O), 824 (C-Cl); ¹H NMR (500 MHz, CDCl₃, ppm): δ 8.40 (d, 1H, J = 2.20 Hz, Py-2-H), 7.84 (d, 2H, J = 8.55 Hz, Ar′-2,6-H),7.71 (dd, 1H, J₁ = 2.45 Hz, J₂ = 2.30 Hz, Py-4-H), 7.40 (d, 2H, J = 8.50 Hz, Ar′-3,5-H), 7.34 (d, 1H, J = 8.25 Hz, Py-5-H), 7.18 (d, 2H, J = 8.70 Hz, Ar-2,6-H), 6.83 (d, 2H, J = 8.60 Hz, Ar-3,5-H), 4.98 (s, 2H, Py—CH₂—), 4.26–4.15 (m, 2H, —CO₂—CH₂—), 4.12–4.07 (m, 1H, Ar—CH—), 3.97 (q, 2H, —CO₂—CH₂—), 3.77 (d, 1H, J = 9.75 Hz, —CO₂—CH—), 3.51 (dd, 1H, J₁ = 4.20 Hz, J₂ = 4.25 Hz, —CO—CH—), 3.35 (dd, 1H, J₁ = 9.75 Hz, J₂ = 9.65 Hz, —CO—CH—), 1.25 (t, 3H, J₁ = 7.25 Hz, J₂ = 7.00 Hz, —CO₂—CH₂—CH₃), 1.03 (t, 3H, J₁ = 7.05 Hz, J₂ = 7.15 Hz, —CO₂—CH₂—CH₃); ¹³C NMR (125 MHz, CDCl₃, ppm): δ 196.5, 168.3, 167.7, 157.1, 151.1, 148.7, 139.5, 138.1, 135.0, 133.1, 131.5, 129.6, 129.4, 128.9, 124.2, 114.6, 66.6, 61.7, 61.4, 57.6, 42.8, 40.2, 14.0, 13.8; MS (ESI) m/z: 566.3 ([M + Na]⁺). Anal. Calcd for C₂₈H₂₇Cl₂NO₆: C, 61.77; H, 5.00; N, 2.57. Found: C, 61.52; H, 5.12; N, 2.64.

2.2.2.19

2.2.2.19 Diethyl 2-(1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-(2,4-dichlorophenyl)-3-oxopropyl)malonate (5s)

Yield, 41%; white solid; m.p. 71–73 °C; IR (KBr, cm⁻¹): ν 2849–3088 (C—H), 1734 (—O—C⚌O), 1684 (Ar′—C⚌O), 1458–1609 (C⚌C and benzene and Py-ring), 1300 (C—N), 1244 (Ar—C—O), 1153 (—CH₂—O—C⚌O), 826 (C—Cl); ¹H NMR (500 MHz, CDCl₃, ppm): δ 8.43 (d, 1H, J = 2.25 Hz, Py-2-H), 7.73 (dd, 1H, J₁ = 2.40 Hz, J₂ = 2.50 Hz, Py-4-H), 7.37–7.34 (m, 2H, Ar′-6-H, Py-5-H), 7.22 (dd, 1H, J₁ = 2.05 Hz, J₂ = 1.75 Hz, Ar′-3-H), 7.17–7.14 (m, 3H, Ar′-5-H, Ar-2,6-H), 6.83 (d, 2H, J = 8.65 Hz, Ar-3,5-H), 5.00 (s, 2H, Py—CH₂—), 4.23–4.19 (m, 2H, —CO₂—CH₂—), 4.03–3.94 (m, 3H, Ar—CH—, —CO₂—CH₂—), 3.71 (d, 1H, J = 9.75 Hz, —CO₂—CH—), 3.49 (dd, 1H, J₁ = J₂ = 4.40 Hz, —CO—CH—), 3.38 (dd, 1H, J₁ = 10.05 Hz, J₂ = 9.95 Hz, —CO—CH—), 1.26 (t, 3H, J₁ = 7.05 Hz, J₂ = 7.20 Hz, —CO₂—CH₂—CH₃), 1.03 (t, 3H, J₁ = 7.00 Hz, J₂ = 7.25 Hz, —CO₂—CH₂—CH₃); ¹³C NMR (125 MHz, CDCl₃, ppm): δ 199.6, 168.2, 167.6, 157.3, 151.2, 148.8, 138.1, 137.3, 132.9, 132.0, 131.6, 130.3, 129.7, 127.3, 124.3, 114.8, 66.7, 61.8, 61.5, 57.6, 46.8, 40.3, 14.1, 13.9; MS (ESI) m/z: 600.3 ([M + Na]⁺). Anal. Calcd for C₂₈H₂₆Cl₃NO₆: C, 58.10; H, 4.53; N, 2.42. Found: C, 57.86; H, 4.84; N, 2.33.

2.2.2.20

2.2.2.20 Diethyl 2-(1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-(4-ethoxyphenyl)-3-oxopropyl)malonate (5t)

Yield, 40%; white solid; m.p. 88–90 °C; IR (KBr, cm⁻¹): ν 2913–2986 (C—H), 1738 (—O—C⚌O), 1667 (Ar′—C⚌O), 1458–1603 (C⚌C and benzene and Py-ring), 1308 (C—N), 1254 (Ar—C—O), 1179 (—CH₂—O—Ar′), 1150 (—CH₂—O—C⚌O), 822 (C—Cl); ¹H NMR (500 MHz, CDCl₃, ppm): δ 8.41 (d, 1H, J = 2.00 Hz, Py-2-H), 7.88 (d, 2H, J = 8.80 Hz, Ar′-2,6-H), 7.71 (dd, 1H, J₁ = 2.30 Hz, J₂ = 2.50 Hz, Py-4-H), 7.34 (d, 1H, J = 8.20 Hz, Py-5-H), 7.19 (d, 2H, J = 8.60 Hz, Ar-2,6-H), 6.88 (d, 2H, J = 8.95 Hz, Ar′-3,5-H), 6.82 (d, 2H, J = 8.65 Hz, Ar-3,5-H), 4.98 (s, 2H, Py—CH₂—), 4.25–4.06 (m, 5H, —CO₂—CH₂—, Ar—CH—, Ar′—OCH₂—), 3.96 (q, 2H, —CO₂—CH₂—), 3.77 (d, 1H, J = 9.75 Hz, —CO₂—CH—), 3.45 (dd, 1H, J₁ = 4.40 Hz, J₂ = 4.25 Hz, —CO—CH—), 3.33 (dd, 1H, J₁ = 9.65 Hz, J₂ = 9.70 Hz, —CO—CH—), 1.43 (t, 3H, J₁ = 6.90 Hz, J₂ = 6.95 Hz, Ar′—OCH₂—CH₃), 1.25 (t, 3H, J₁ = 7.00 Hz, J₂ = 7.20 Hz, —CO₂—CH₂—CH₃), 1.02 (t, 3H, J₁ = 7.20 Hz, J₂ = 7.10 Hz, —CO₂—CH₂—CH₃); ¹³C NMR (125 MHz, CDCl₃, ppm): δ 196.1, 168.4, 167.8, 162.9, 157.0, 151.1, 148.7, 138.1, 133.4, 131.6, 130.4, 129.6, 129.5, 124.2, 114.5, 114.1, 66.6, 63.7, 61.7, 61.3, 57.7, 42.4, 40.3, 14.7, 14.1, 13.8; MS (ESI) m/z: 576.4 ([M + Na]⁺). Anal. Calcd for C₃₀H₃₂ClNO₇: C, 65.04; H, 5.82; N, 2.53. Found: C, 65.24; H, 5.50; N, 3.00.

2.2.2.21

2.2.2.21 Diethyl 2-(1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-(4-fluorophenyl)-3-oxopropyl)malonate (5u)

Yield, 52%; white solid; m.p. 65–67 °C; IR (KBr, cm⁻¹): ν 2932–3065 (C—H), 1740 (—O—C⚌O), 1684 (Ar′—C⚌O), 1458–1599 (C⚌C and benzene and Py-ring), 1314 (C—N), 1260 (C—F), 1236 (Ar—C—O), 1159 (—CH₂—O—C⚌O), 824 (C—Cl); ¹H NMR (500 MHz, CDCl₃, ppm): δ 8.40 (d, 1H, J = 2.00 Hz, Py-2-H), 7.94–7.91 (m, 2H, Ar′-2,6-H), 7.70 (dd, 1H, J₁ = 2.30 Hz, J₂ = 2.35 Hz, Py-4-H), 7.32 (d, 1H, J = 8.20 Hz, Py-5-H), 7.19 (d, 2H, J = 8.60 Hz, Ar-2,6-H), 7.09 (t, 2H, J₁ = 8.55 Hz, J₂ = 8.60 Hz, Ar′-3,5-H), 6.83 (d, 2H, J = 8.60 Hz, Ar-3,5-H), 4.98 (s, 2H, Py—CH₂—), 4.26–4.15 (m, 2H, —CO₂—CH₂—), 4.13–4.09 (m, 1H, Ar—CH—), 3.97 (q, 2H, —CO₂—CH₂—), 3.78 (d, 1H, J = 9.65 Hz, —CO₂—CH—), 3.51 (dd, 1H, J₁ = 4.35 Hz, J₂ = 4.20 Hz, —CO—CH—), 3.37 (dd, 1H, J = 9.6 Hz, —CO—CH—), 1.25 (t, 3H, J₁ = 7.15 Hz, J₂ = 7.05 Hz, —CO₂—CH₂—CH₃), 1.03 (t, 3H, J₁ = 7.15 Hz, J₂ = 7.05 Hz, —CO₂—CH₂—CH₃); ¹³C NMR (125 MHz, CDCl₃, ppm): δ 196.2, 168.4, 167.8, 166.8, 164.8, 157.2, 151.2, 148.8, 138.2, 135.1, 133.3, 131.7, 130.9, 130.8, 129.5, 124.3, 115.8, 115.6, 114.8, 66.7, 61.8, 61.4, 57.7, 42.8, 40.3, 14.1, 13.9; ¹⁹F NMR (470 MHz, CDCl₃, ppm): δ −105.10; MS (ESI) m/z: 550.3 ([M + Na]⁺). Anal. Calcd for C₂₈H₂₇ClFNO₆: C, 63.70; H, 5.15; N, 2.65. Found: C, 63.33; H, 5.34; N, 2.70.

2.2.2.22

2.2.2.22 Diethyl 2-(1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-(4-isopropylphenyl)-3-oxopropyl)malonate (5v)

Yield, 45%; white solid; m.p. 80–82 °C; IR (KBr, cm⁻¹): v 2874–2974 (C—H), 1728 (—O—C⚌O), 1676 (Ar′—C⚌O), 1458–1609 (C⚌C and benzene and Py-ring), 1292 (C—N), 1238 (Ar—C—O), 1157 (—CH₂—O—C⚌O), 824 (C—Cl); ¹H NMR (500 MHz, CDCl₃, ppm): δ 8.41 (d, 1H, J = 2.30 Hz, Py-2-H), 7.84 (d, 2H, J = 8.25 Hz, Ar′-2,6-H), 7.71 (dd, 1H, J₁ = 2.50 Hz, J₂ = 2.40 Hz, Py-4-H), 7.34 (d, 1H, J = 8.25 Hz, Py-5-H), 7.28 (d, 2H, J = 8.40 Hz, Ar-2,6-H), 7.20 (d, 2H, J = 8.65 Hz, Ar′-3,5-H), 6.82 (d, 2H, J = 8.75 Hz, Ar-3,5-H), 4.98 (s, 2H, Py—CH₂—), 4.24–4.11 (m, 3H, —CO₂—CH₂—, Ar—CH—), 3.96 (q, 2H, —CO₂—CH₂—), 3.78 (d, 1H, J = 9.75 Hz, —CO₂—CH—), 3.48 (dd, 1H, J₁ = J₂ = 4.30 Hz, —CO—CH—), 3.39 (dd, 1H, J₁ = J₂ = 9.60 Hz, —CO—CH—), 2.97–2.92 (m, 1H, Ar′—CH—), 1.26–1.24 (m, 9H, Ar′—CH—(CH₃)₂, —CO₂—CH₂—CH₃), 1.03 (t, 3H, J₁ = 7.15 Hz, J₂ = 7.05 Hz, —CO₂—CH₂—CH₃); ¹³C NMR (125 MHz, CDCl₃, ppm): δ 197.2, 168.4, 167.8, 157.0, 154.6, 151.1, 148.7, 138.1, 134.6, 133.5, 131.6, 129.5, 128.4, 126.7, 124.2, 114.6, 66.6, 61.7, 61.4, 57.7, 42.6, 40.1, 34.2, 23.7, 14.1, 13.8; MS (ESI) m/z: 574.4 ([M + Na]⁺). Anal. Calcd for C₃₁H₃₄ClNO₆: C, 67.44; H, 6.21; N, 2.54. Found: C, 67.25; H, 6.10; N, 2.61.

2.3

2.3 Antiviral activities against CMV

2.3.1

2.3.1 Purification of CMV

Nicotiana tabacum L. leaves inoculated with CMV were selected, ground in phosphate butter, and then filtered through a double-layer pledget by using the method of Zhou et al. (1995). The filtrate was centrifuged at 8000g, and the supernatant liquid was collected as the crude extract of the virus. All of the experiments were performed at 4 °C.

The virus concentration was calculated as $Virus concentration (mg / mL) = (A_{260} \times dilution ratio) / E_{1 cm}^{0.1 % 260 nm}$

where E represents the extinction coefficient of TMV and $E_{1 cm}^{0.1 % 260 nm}$ is 3.1.

2.3.2

2.3.2 Curative activities of the title compounds against CMV in vivo

Leaves of the same age were gathered from Chenopodium amaranticolor. Crude CMV (6 × 10⁻³ mg/mL) was inoculated using a brush on whole leaves on which silicon carbide had previously been scattered. After 0.5–1 h, the leaves were washed with water and dried. The compound solution was then smeared on the right side of leaves, and solvent was smeared on the left side as a control. The number of local lesions that developed was recorded 3–4 d after inoculation. All compounds were tested with three repetitions to ensure accuracy in the results.

2.3.3

2.3.3 Protection activities of the title compounds against CMV in vivo

Leaves of C. amaranticolor of the same age were selected. The compound solution was smeared on the right side of the leaves. Meanwhile, the solvent was smeared on the left side as control. After 12 h, crude CMV, at the concentration of 6 × 10⁻³ mg/mL, was inoculated with a brush on whole leaves, which had previously been scattered with silicon carbide. After 0.5–1 h, the leaves were washed with water and dried. The number of local lesions was then recorded 3–4 d after inoculation. All compounds were tested with three repetitions to ensure veracity of the results.

2.3.4

2.3.4 Inactivation activities of the title compounds against CMV in vivo

The virus was inhibited by mixing with the compound solution at the same volume for 0.5 h. The right side of C. amaranticolor leaves was then inoculated with the mixture and CMV diluted to suitable concentration (6 × 10⁻³ mg/mL) was inoculated on the left side as control, of leaves that had previously been scattered with silicon carbide. After 0.5–1 h, the leaves were washed with water and dried. The number of local lesions was recorded 3–4 d after inoculation. All compounds were tested with three repetitions to ensure veracity of the results.

The inhibitory rates of the target compounds were calculated according to the following formula (“av” means average):

Inhibition rate (%) = [(av local lesion no of control (not treated with compound solution) − av local lesion no smeared with drugs)/av local lesion no of control (not treated with compound solution)] × 100%.

2.4

2.4 3D-QSAR analysis

2.4.1

2.4.1 Datasets for 3D-QSAR analysis

The data of 22 target compounds were obtained, and biological activity was expressed as pEC₅₀. A total of 16 compounds (labeled with asterisks) were randomly chosen as the training set for CoMFA (Cramer et al., 1988), and the remaining 6 compounds were used as the testing set.

2.4.2

2.4.2 Molecular modeling and alignment

Molecular modeling and CoMFA analysis were performed using SYBYL 7.3 (Tripos Inc., St. Louis, MO, USA) software. The 3D structures of all molecules were built using the Sketch Molecule function in SYBYL. Initial optimization of the structures was conducted using the Gasteiger–Hückel charge, Tripos force field, and Powell conjugate gradient algorithm with a convergence criterion of 0.005 kcal/mol Å (Huang et al., 2011). The 3D structures of the 22 molecules were aligned to the common template molecule of 5l to reveal the best curative activity against CMV in the CoMFA model study.

2.4.3

2.4.3 Partial least-squares analysis

3D-QSAR was derived using partial least square (PLS) analysis wherein molecules were placed in a rectangular grid, and interaction energies between a probe atom and all compounds were computed at surrounding points by using a volume-dependent lattice with a 2.0 grid spacing (default in SYBYL) to improve the signal-to-noise ratio (Elizabeth and William, 2006). CoMFA descriptors were used as independent variables, and experimental pEC₅₀ values were presented as the dependent variables. 3D-QSAR analysis was then conducted in two steps by using the PLS technique. First, the performance of the models was evaluated by leave-one-out cross-validation, and the optimal number of components (ONC) was determined with the highest cross-validated q² (Baroni et al., 1992). The non-cross-validated correlation coefficient r², standard error of estimate (SEE), and F were subsequently calculated according to the definitions in the SYBYL 7.3 package. Contour maps and standard deviations of CoMFA were generated by using PLS coefficients.

3 Results and discussion

3.1

3.1 Chemistry

High product yields, good molar equivalence, suitable reaction temperatures, and short reaction times encouraged us to apply previously reported methods under optimized reaction conditions with the aim of synthesizing title compounds. Thus, the reactions were carried out using the key intermediate 4a and diethyl malonate as the starting materials and the synthesis of the target compound 5l as the model reaction. The effects of different reaction solvents, catalysts, molar equivalents, and reaction temperatures on the yields and reaction times of the target compounds were determined. As shown in Table 1, the highest yield (71.2%) and shortest reaction time (0.5 h) were obtained when the reaction solvent, catalyst, molar equivalent, and reaction temperature were C₂H₅OH, KOH, 1:5:1, and 80 °C, respectively. Therefore, the target compounds 5a–5v were synthesized under the following optimal conditions: solvent, C₂H₅OH (CH₃OH); catalyst, KOH; temperature, 80 °C; and molar equivalent of 4: diethyl (dimethyl) malonate:catalyst, 1:5:1. The IR spectra of compounds 5a–5v showed characteristic absorption bands at 2837–3088 cm⁻¹, which reveals the presence of C—H. The stretching frequency at 1663–1749 cm⁻¹ was assigned to C⚌O vibrations. Bands at 1150–1262 and 818–833 cm⁻¹ revealed the respective stretching vibrations of C—O and C—Cl groups of the chalcone skeleton. ¹H NMR spectra showed one sharp peak appearing at 4.95–5.01 ppm, which indicates the presence of Py—CH₂—, and a doublet appearing at 3.72–3.84 ppm, which indicates the presence of —CH—(CO₂R₂)₂. Chemical shifts at approximately 197.6, 168.7, and 168.2 ppm in ¹³C NMR spectra confirmed the presence of C⚌O; a chemical shift at approximately 66.6 ppm confirmed the presence of Py—CH₂—.

Table 1 Selection of conditions for the reaction of the target compound 5l.

Entry	Solvent	Catalyst	Molar equivalent (4a:diethyl malonate:catalyst)	T (°C)	t (h)	Yield (%)
1	EtOH	KOH	1:1:0.5	80	4	37.4
2	EtOH	KOH	1:1:1	80	2	44.9
3	EtOH	KOH	1:2:1	80	1	61.0
4	EtOH	KOH	1:5:1	80	0.5	71.2
5	EtOH	KOH	1:5:1	20	12	43.4
6	EtOH	KOH	1:5:1	40	8	56.7
7	EtOH	KOH	1:5:1	60	3	62.2
8	THF	KOH	1:5:1	65	3	–^a
9	EtOH	NaOH	1:5:1	80	1	68.0
10	EtOH	KOH	1:5:1	80	3	10.6

a No reaction.

3.2

3.2 Antiviral activity

The antiviral activities of the target compounds 5a–5v against CMV were assayed with ningnanmycin as the control. Table 2 shows that most of the title compounds present moderate to good antiviral activity against CMV in vivo. In particular, among the compounds tested, 5l and 5n exhibited excellent curative activities with inhibition rates as high as 69.8% and 65.0% at 500 μg/mL; these rates are better than that reported for ningnanmycin (56.9%). Compounds 5l and 5n showed increased CMV inactivation rates of 88.1% and 88.6%, respectively, which are nearly similar to that of ningnanmycin (92.2%). Compound 5n also possessed good protective activity against CMV, with an inhibition rate of 54.9% at 500 μg/mL; this rate is only slightly lower than that of ningnanmycin (58.3%).

Using the results of preliminary bioassays as bases, the EC₅₀ values of the title compounds were evaluated and are summarized in Table 3. Compounds 5l and 5n exhibited notable curative activities against CMV with EC₅₀ values of 186.2 and 211.5 μg/mL, respectively; these values are even better than that of ningnanmycin (330.5 μg/mL).

3.3

3.3 Performance of the CoMFA model

A CoMFA model based on the experimental EC₅₀ values of the training set was developed for the 3D-QSAR study. The predicted and experimental pEC₅₀ values of compounds in both the training and testing sets are presented in Table 4, and correlations between the predicted and experimental pEC₅₀ values in the CoMFA model are presented in Fig. 1. Overall, the predicted pEC₅₀ values were very similar to the corresponding experimental values among compounds in both the training and testing sets (Table 4). The mostly linear correlation in Fig. 1 demonstrated the high predictive power of the developed model. The calculated statistical parameters of the CoMFA model are shown in Table 5. The cross-validated coefficient q², non-cross-validated correlation coefficient r², SEE, and F of the model were 0.517 (>0.5) with 6 ONC, 0.990, 0.036, and 143.396, respectively. The relative contributions of steric and electrostatic to the CoMFA model were 0.658 and 0.342, respectively; these values suggest that bioactivity is mainly determined by steric interactions.

Table 4 Experimental and predicted pEC₅₀ results against CMV.

Compd.	Experimental^a	Predicted^b	Residual^c
^⁎5a	2.581	2.597	0.016
5b	2.587	2.584	−0.003
^⁎5c	2.796	2.800	0.004
^⁎5d	3.061	3.046	−0.015
^⁎5e	3.196	3.161	−0.035
^⁎5f	3.017	3.043	0.026
^⁎5g	2.614	2.599	−0.015
5h	2.502	2.481	−0.021
^⁎5i	2.606	2.611	0.005
^⁎5j	2.383	2.399	0.016
^⁎5k	2.814	2.796	−0.018
^⁎5l	3.437	3.427	−0.010
^⁎5m	3.116	3.124	0.008
5n	3.393	3.465	0.072
5o	3.088	3.338	0.250
^⁎5p	2.996	3.053	0.057
5q	3.206	3.353	0.153
^⁎5r	2.651	2.680	0.029
^⁎5s	2.707	2.642	−0.065
^⁎5t	2.720	2.723	0.003
^⁎5u	2.748	2.741	−0.007
5x	3.072	3.185	0.113

a Experimental pEC₅₀.

b Predicted by CoMFA.

c Relative error of the experimentally predicted pEC₅₀ (b–a).

⁎ Samples of the training set.

Graph of predicted pEC50 versus experimental pEC50 for the CoMFA model.

Table 5 Statistical parameters for the CoMFA model.

Statistical parameter	CoMFA
q^2a	0.517
ONC^b	6
r^2c	0.990
SEE^d	0.036
F^e	143.396
Fraction of field contributions^f
Steric	0.658
Electrostatic	0.342

a Cross-validated correlation.

b Optimum number of components.

c Noncross-validated correlation.

d Standard error of estimate.

e F-test value.

f Field contributions: steric and electrostatic.

CoMFA contour maps of the steric and electrostatic fields for antiviral activity against CMV are shown in Fig. 2. Green contours in the CoMFA steric field indicate regions where bulky groups increase activity, whereas yellow contours indicate regions where bulky groups decrease activity. Fig. 2A shows two large yellow contours around the benzene ring; this result indicates that bulky substituent groups at the position of R₁ are unfavorable. For example, a molecule with a Ph (i.e., 5l) substituent showed better activity than that with a 4-OC₂H₅-Ph (5t) moiety at the R₁ position. A green contour was found near the R₂ substituent position, which suggests that bulky groups are favorable at this position. The results of the contour map agreed well with experimental data showing that replacement of methyl with ethyl at the R₂ substituent position results in increases in activity following the order of 5l > 5a, 5m > 5b, and 5n > 5c. An electrostatic contour map of the CoMFA model is displayed in Fig. 2B; here, blue contours indicate regions where electron-withdrawing groups would increase activity and red contours indicate regions where electron-donating groups would increase activity. As shown in Fig. 2B, several large regions of the red contours were observed near the phenyl ring, which indicates that electron-donating substituent groups at the position of the phenyl ring help increase the activity of the compounds. The contour maps agreed well with experimental data showing that replacement of —F with —H or —CH₃ at the R₁ substituent position on the phenyl ring results in increases in activity following the order of 5l > 5u and 5o > 5u.

CoMFA contour maps of the steric (A) and electrostatic (B) fields.

4 Conclusion

In summary, novel chalcone derivatives containing malonate and pyridine moieties were prepared and evaluated in terms of their antiviral activities against CMV. The structures of all of the compounds were identified using spectral data (¹H NMR, ¹³C NMR, ¹⁹F NMR, MS, and IR) and elemental analyses. Bioassay results showed that most of the compounds possess good antiviral activity against CMV in vivo; in particular, compounds 5l and 5n exhibited higher curative activities than ningnanmycin. The CoMFA model established based on the anti-CMV activities of the target compounds showed high predictive ability. The present work successfully demonstrated that chalcone derivatives containing malonate and pyridine moieties can effectively control CMV. Further studies on the structural optimization and modes of action of these compounds are ongoing in our laboratory.

Acknowledgments

The authors gratefully acknowledge the National Natural Science Foundation of China (Nos. 21132003 and 21362004) and Collaborative Innovation Center for Natural Products and Biological Drugs of Yunnan for supporting the project.

References

Abad J., Anastasio G., Fraile A., García-Arenal F., . A search for resistance to cucumber mosaic virus in the genus Lycopersicon. J. Plant. Pathol.. 2000;82:39-48.
[Google Scholar]
Ahmeda O.M., Mohamed M.A., Ahmed R.R., Ahmed S.A., . Synthesis and anti-tumor activities of some new pyridines and pyrazolo [1,5-a] pyrimidines. Eur. J. Med. Chem.. 2009;44:3519-3523.
[Google Scholar]
Bandgar B.P., Patil S.A., Korbad B.L., Nile S.H., Khobragade C.N., . Synthesis and biological evaluation of β-chloro vinyl chalcones as inhibitors of TNF-α and IL-6 with antimicrobial activity. Eur. J. Med. Chem.. 2010;45:2629-2633.
[Google Scholar]
Baroni M., Clementi S., Cruciani G., Costantino G., Riganelli D., Oberrauch E., . Predictive ability of regression models. Part II. Selection of the best predictive PLS model. J. Chemom.. 1992;6:347-356.
[Google Scholar]
Brandau S., Landa A., Franzén J., Marigo M., Jørgensen K.A., . Organocatalytic conjugate addition of malonates to α, β-unsaturated aldehydes: asymmetric formal synthesis of (−)-paroxetine, chiral lactams, and lactones. Angew. Chem.. 2006;118:4411-4415.
[Google Scholar]
Chen M.H., Chen Z., Song B.A., Bhadury P.S., Yang S., Cai X.J., Hu D.Y., Xue W., Zeng S., . Synthesis and antiviral activities of chiral thiourea derivatives containing an α-aminophosphonate moiety. J. Agric. Food Chem.. 2009;57:1383-1388.
[Google Scholar]
Choudhary A.N., Juyal V., . Synthesis of chalcone and their derivatives as antimicrobial agents. Int. J. Pharm. Pharm. Sci.. 2011;3:125-128.
[Google Scholar]
Cramer R.D.I.I.I., Patterson D.E., Bunce J.D., . Comparative molecular field analysis (CoMFA). Effect of shape on binding of steroids to carrier proteins. J. Am. Chem. Soc.. 1988;110:5959-5967.
[Google Scholar]
Elizabeth A.A., William J.W., . Highly predictive CoMFA and CoMSIA models for two series of stromelysin-1 (MMP-3) inhibitors elucidate S1′ and S1–S2′ binding modes. J. Chem. Inf. Model.. 2006;46:1775-1783.
[Google Scholar]
Gallitelli D., . The ecology of cucumber mosaic virus and sustainable agriculture. Virus Res.. 2000;71:9-21.
[Google Scholar]
González J.A., Estévez-Braun A., . Effect of (E)-chalcone on potato-cyst nematodes (Globodera pallida and G. rostochiensis) J. Agric. Food Chem.. 1998;46:1163-1165.
[Google Scholar]
Huang X.Y., Shan Z.J., Zhai H.L., Li L.N., Zhang X.Y., . Molecular design of anticancer drug leads based on three-dimensional quantitative structure activity relationship. J. Chem. Inf. Model.. 2011;51:1999-2006.
[Google Scholar]
Kang S.H., Song B.A., Wu J., He M., Hu D.Y., Jin L.H., Zeng S., Xue W., Yang S., . Design, synthesis and insecticidal activities of novel acetamido derivatives containing N-pyridylpyrazole carboxamides. Eur. J. Med. Chem.. 2013;67:14-18.
[Google Scholar]
Lin C.H., Sheu F., Lin H.T., Pan T.M., . Allergenicity assessment of genetically modified cucumber mosaic virus (CMV) resistant tomato (Solanum lycopersicon) J. Agric. Food Chem.. 2010;58:2302-2306.
[Google Scholar]
Liu M., Wilairat P., Go L.M., . Antimalarial alkoxylated and hydroxylated chalcones: structure–activity relationship analysis. J. Med. Chem.. 2001;44:4443-4452.
[Google Scholar]
Liu Y.X., Wei D.G., Zhu Y.R., Liu S.H., Zhang Y.L., Zhao Q.Q., Cai B.L., Li Y.H., Song H.B., Liu Y., Wang Y., Huang R.Q., Wang Q.M., . Synthesis, herbicidal activities, and 3D-QSAR of 2-cyanoacrylates containing aromatic methylamine moieties. J. Agric. Food Chem.. 2008;56:204-212.
[Google Scholar]
Luo H., Liu J.J., Jin L.H., Hu D.Y., Chen Z., Yang S., Wu J., Song B.A., . Synthesis and antiviral bioactivity of novel (1E,4E)-1-aryl-5-(2-(quinazolin-4-yloxy)phenyl)-1,4-pentadien-3-one derivatives. Eur. J. Med. Chem.. 2013;3:662-669.
[Google Scholar]
Ma J., Li P., Li X.Y., Shi Q.C., Wan Z.H., Hu D.Y., Jin L.H., Song B.A., . Synthesis and antiviral bioactivity of novel 3-((2-((1E,4E)-3-oxo-5-arylpenta-1,4-dien-1-yl)phenoxy)methyl)quinazolin-4(3H)-one derivatives. J. Agric. Food Chem.. 2014;62:8928-8934.
[Google Scholar]
Palukaitis P., Roossinck M.J., Dietzgen R.G., Francki R.I., . Cucumber mosaic virus. Adv. Virus Res.. 1992;41:281-348.
[Google Scholar]
Patel N.B., Patel H.R., . Characterization and pharmacological evaluation of new pyridine analogs. Arab. J. Chem.. 2012;5:81-91.
[Google Scholar]
Ragoussis V., Panopoulou M., Ragoussis N., . Concise preparation of the (3E,5Z)-alkadienyl system. New approach to the synthesis of principal insect sex pheromone constituents. J. Agric. Food Chem.. 2004;52:5047-5051.
[Google Scholar]
Ritzenthaler C., . Resistance to plant viruses: old issue, new answer. Curr. Opin. Biotechnol.. 2005;16:118-122.
[Google Scholar]
Song B.A., Yang S., Jin L.H., Bhadury P.S., . Environment-Friendly Antiviral Agents for Plants. Berlin: Springer; 2009.
Stamova B.S., Chetelat R.T., . Inheritance and genetic mapping of cucumber mosaic virus resistance introgressed from Lycopersicon chilense into tomato. Theor. Appl. Genet.. 2000;101:527-537.
[Google Scholar]
Sulistyowati E., Mitter N., Bastiaan-Net S., Roossinck M.J., Dietzgen R.G., . Host range, symptom expression and RNA 3 sequence analyses of six Australian strains of cucumber mosaic virus. Australas. Plant. Pathol.. 2004;33:505-512.
[Google Scholar]
Thirunarayanan G., Vanangamudi G., . Synthesis, spectral studies, antimicrobial and insect antifeedant activities of some substituted styryl 4′-fluorophenyl ketones. Arab. J. Chem.. 2014;7:1185-1191.
[Google Scholar]
Vincenzo R.D., Ferlini C., Distefano M., Gaggini C., Riva A., Bombardelli E., Morazzoni P., Valenti P., Belluti F., Ranelletti F.O., Mancuso S., Scambia G., . In vitro evolution of newly developed chalcone analogues in human cancer cells. Cancer Chemother. Pharmacol.. 2000;46:305-312.
[Google Scholar]
Wang Z.W., Wei P., Wang L.Z., Wang Q.M., . Design, synthesis, and anti-tobacco mosaic virus (TMV) activity of phenanthroindolizidines and their analogues. J. Agric. Food Chem.. 2012;60:10212-10219.
[Google Scholar]
Wheeler T.N., . Synthesis and insecticidal activities of pyrethroids derived from 3-methyl-2-(3,4-dihydronaphthyl) butanoic acids. J. Agric. Food Chem.. 1984;32:1125-1129.
[Google Scholar]
Woo E.R., Fujii I., Ebizuka Y., Sankawa U., Kawaguchi A., Huang S.Y., Beale J.M., Shibuya M., Mocek U., Floos H.G., . Nonstereospecific proton removal in the enzymatic formation of orsellinic acid from chiral malonate. J. Am. Chem. Soc.. 1989;111:5498-5500.
[Google Scholar]
Xiao H., Li P., Hu D.Y., Song B.A., . Synthesis and anti-TMV activity of novel β-amino acid ester derivatives containing quinazoline and benzothiazole moieties. Bioorg. Med. Chem. Lett.. 2014;24:3452-3454.
[Google Scholar]
Yoshimura M., Sano A., Kamei J.I., Obata A., . Identification and quantification of metabolites of orally administered naringenin chalcone in rats. J. Agric. Food Chem.. 2009;57:6432-6437.
[Google Scholar]
Zhao P.L., Liu C.L., Huang W., Wang Y.Z., Yang G.F., . Synthesis and fungicidal evaluation of novel chalcone-based strobilurin analogues. J. Agric. Food Chem.. 2007;46:1163-1165.
[Google Scholar]
Zhou X.P., Xu Z.X., Xu J., . The research of cucumber mosaic virus which infected loofah. J. South Chin. Agric. Univ.. 1995;16:74-79.
[Google Scholar]

Appendix A

Supplementary material

Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/j.arabjc.2015.05.003.

Appendix A

Supplementary material

Supplementary data 1

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Introduction

Experimental

Materials and methods
Chemistry
Antiviral activities against CMV
3D-QSAR analysis

Results and discussion

Chemistry
Antiviral activity
Performance of the CoMFA model

Conclusion

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[1] Abad J., Anastasio G., Fraile A., García-Arenal F., . A search for resistance to cucumber mosaic virus in the genus Lycopersicon. J. Plant. Pathol.. 2000;82:39-48.
[Google Scholar]

[2] Ahmeda O.M., Mohamed M.A., Ahmed R.R., Ahmed S.A., . Synthesis and anti-tumor activities of some new pyridines and pyrazolo [1,5-a] pyrimidines. Eur. J. Med. Chem.. 2009;44:3519-3523.
[Google Scholar]

[3] Bandgar B.P., Patil S.A., Korbad B.L., Nile S.H., Khobragade C.N., . Synthesis and biological evaluation of β-chloro vinyl chalcones as inhibitors of TNF-α and IL-6 with antimicrobial activity. Eur. J. Med. Chem.. 2010;45:2629-2633.
[Google Scholar]

[4] Baroni M., Clementi S., Cruciani G., Costantino G., Riganelli D., Oberrauch E., . Predictive ability of regression models. Part II. Selection of the best predictive PLS model. J. Chemom.. 1992;6:347-356.
[Google Scholar]

[5] Brandau S., Landa A., Franzén J., Marigo M., Jørgensen K.A., . Organocatalytic conjugate addition of malonates to α, β-unsaturated aldehydes: asymmetric formal synthesis of (−)-paroxetine, chiral lactams, and lactones. Angew. Chem.. 2006;118:4411-4415.
[Google Scholar]

[6] Chen M.H., Chen Z., Song B.A., Bhadury P.S., Yang S., Cai X.J., Hu D.Y., Xue W., Zeng S., . Synthesis and antiviral activities of chiral thiourea derivatives containing an α-aminophosphonate moiety. J. Agric. Food Chem.. 2009;57:1383-1388.
[Google Scholar]

[7] Choudhary A.N., Juyal V., . Synthesis of chalcone and their derivatives as antimicrobial agents. Int. J. Pharm. Pharm. Sci.. 2011;3:125-128.
[Google Scholar]

[8] Cramer R.D.I.I.I., Patterson D.E., Bunce J.D., . Comparative molecular field analysis (CoMFA). Effect of shape on binding of steroids to carrier proteins. J. Am. Chem. Soc.. 1988;110:5959-5967.
[Google Scholar]

[9] Elizabeth A.A., William J.W., . Highly predictive CoMFA and CoMSIA models for two series of stromelysin-1 (MMP-3) inhibitors elucidate S1′ and S1–S2′ binding modes. J. Chem. Inf. Model.. 2006;46:1775-1783.
[Google Scholar]

[10] Gallitelli D., . The ecology of cucumber mosaic virus and sustainable agriculture. Virus Res.. 2000;71:9-21.
[Google Scholar]

[11] González J.A., Estévez-Braun A., . Effect of (E)-chalcone on potato-cyst nematodes (Globodera pallida and G. rostochiensis) J. Agric. Food Chem.. 1998;46:1163-1165.
[Google Scholar]

[12] Huang X.Y., Shan Z.J., Zhai H.L., Li L.N., Zhang X.Y., . Molecular design of anticancer drug leads based on three-dimensional quantitative structure activity relationship. J. Chem. Inf. Model.. 2011;51:1999-2006.
[Google Scholar]

[13] Kang S.H., Song B.A., Wu J., He M., Hu D.Y., Jin L.H., Zeng S., Xue W., Yang S., . Design, synthesis and insecticidal activities of novel acetamido derivatives containing N-pyridylpyrazole carboxamides. Eur. J. Med. Chem.. 2013;67:14-18.
[Google Scholar]

[14] Lin C.H., Sheu F., Lin H.T., Pan T.M., . Allergenicity assessment of genetically modified cucumber mosaic virus (CMV) resistant tomato (Solanum lycopersicon) J. Agric. Food Chem.. 2010;58:2302-2306.
[Google Scholar]

[15] Liu M., Wilairat P., Go L.M., . Antimalarial alkoxylated and hydroxylated chalcones: structure–activity relationship analysis. J. Med. Chem.. 2001;44:4443-4452.
[Google Scholar]

[16] Liu Y.X., Wei D.G., Zhu Y.R., Liu S.H., Zhang Y.L., Zhao Q.Q., Cai B.L., Li Y.H., Song H.B., Liu Y., Wang Y., Huang R.Q., Wang Q.M., . Synthesis, herbicidal activities, and 3D-QSAR of 2-cyanoacrylates containing aromatic methylamine moieties. J. Agric. Food Chem.. 2008;56:204-212.
[Google Scholar]

[17] Luo H., Liu J.J., Jin L.H., Hu D.Y., Chen Z., Yang S., Wu J., Song B.A., . Synthesis and antiviral bioactivity of novel (1E,4E)-1-aryl-5-(2-(quinazolin-4-yloxy)phenyl)-1,4-pentadien-3-one derivatives. Eur. J. Med. Chem.. 2013;3:662-669.
[Google Scholar]

[18] Ma J., Li P., Li X.Y., Shi Q.C., Wan Z.H., Hu D.Y., Jin L.H., Song B.A., . Synthesis and antiviral bioactivity of novel 3-((2-((1E,4E)-3-oxo-5-arylpenta-1,4-dien-1-yl)phenoxy)methyl)quinazolin-4(3H)-one derivatives. J. Agric. Food Chem.. 2014;62:8928-8934.
[Google Scholar]

[19] Palukaitis P., Roossinck M.J., Dietzgen R.G., Francki R.I., . Cucumber mosaic virus. Adv. Virus Res.. 1992;41:281-348.
[Google Scholar]

[20] Patel N.B., Patel H.R., . Characterization and pharmacological evaluation of new pyridine analogs. Arab. J. Chem.. 2012;5:81-91.
[Google Scholar]

[21] Ragoussis V., Panopoulou M., Ragoussis N., . Concise preparation of the (3E,5Z)-alkadienyl system. New approach to the synthesis of principal insect sex pheromone constituents. J. Agric. Food Chem.. 2004;52:5047-5051.
[Google Scholar]

[22] Ritzenthaler C., . Resistance to plant viruses: old issue, new answer. Curr. Opin. Biotechnol.. 2005;16:118-122.
[Google Scholar]

[23] Song B.A., Yang S., Jin L.H., Bhadury P.S., . Environment-Friendly Antiviral Agents for Plants. Berlin: Springer; 2009.

[24] Stamova B.S., Chetelat R.T., . Inheritance and genetic mapping of cucumber mosaic virus resistance introgressed from Lycopersicon chilense into tomato. Theor. Appl. Genet.. 2000;101:527-537.
[Google Scholar]

[25] Sulistyowati E., Mitter N., Bastiaan-Net S., Roossinck M.J., Dietzgen R.G., . Host range, symptom expression and RNA 3 sequence analyses of six Australian strains of cucumber mosaic virus. Australas. Plant. Pathol.. 2004;33:505-512.
[Google Scholar]

[26] Thirunarayanan G., Vanangamudi G., . Synthesis, spectral studies, antimicrobial and insect antifeedant activities of some substituted styryl 4′-fluorophenyl ketones. Arab. J. Chem.. 2014;7:1185-1191.
[Google Scholar]

[27] Vincenzo R.D., Ferlini C., Distefano M., Gaggini C., Riva A., Bombardelli E., Morazzoni P., Valenti P., Belluti F., Ranelletti F.O., Mancuso S., Scambia G., . In vitro evolution of newly developed chalcone analogues in human cancer cells. Cancer Chemother. Pharmacol.. 2000;46:305-312.
[Google Scholar]

[28] Wang Z.W., Wei P., Wang L.Z., Wang Q.M., . Design, synthesis, and anti-tobacco mosaic virus (TMV) activity of phenanthroindolizidines and their analogues. J. Agric. Food Chem.. 2012;60:10212-10219.
[Google Scholar]

[29] Wheeler T.N., . Synthesis and insecticidal activities of pyrethroids derived from 3-methyl-2-(3,4-dihydronaphthyl) butanoic acids. J. Agric. Food Chem.. 1984;32:1125-1129.
[Google Scholar]

[30] Woo E.R., Fujii I., Ebizuka Y., Sankawa U., Kawaguchi A., Huang S.Y., Beale J.M., Shibuya M., Mocek U., Floos H.G., . Nonstereospecific proton removal in the enzymatic formation of orsellinic acid from chiral malonate. J. Am. Chem. Soc.. 1989;111:5498-5500.
[Google Scholar]

[31] Xiao H., Li P., Hu D.Y., Song B.A., . Synthesis and anti-TMV activity of novel β-amino acid ester derivatives containing quinazoline and benzothiazole moieties. Bioorg. Med. Chem. Lett.. 2014;24:3452-3454.
[Google Scholar]

[32] Yoshimura M., Sano A., Kamei J.I., Obata A., . Identification and quantification of metabolites of orally administered naringenin chalcone in rats. J. Agric. Food Chem.. 2009;57:6432-6437.
[Google Scholar]

[33] Zhao P.L., Liu C.L., Huang W., Wang Y.Z., Yang G.F., . Synthesis and fungicidal evaluation of novel chalcone-based strobilurin analogues. J. Agric. Food Chem.. 2007;46:1163-1165.
[Google Scholar]

[34] Zhou X.P., Xu Z.X., Xu J., . The research of cucumber mosaic virus which infected loofah. J. South Chin. Agric. Univ.. 1995;16:74-79.
[Google Scholar]

Compd.			Curative activity (%)^a	Protection activity (%)^a	Inactivation activity (%)^a
Compd.	R₁	R₂	Curative activity (%)^a	Protection activity (%)^a	Inactivation activity (%)^a
5a	H	—CH₃	31.0 ± 2.4	28.6 ± 2.1	78.5 ± 1.7
5b	2-CH₃	—CH₃	29.1 ± 1.7	40.0 ± 2.1	82.3 ± 1.7
5c	3-CH₃	—CH₃	39.1 ± 2.0	25.8 ± 1.9	79.1 ± 1.7
5d	4-CH₃	—CH₃	53.8 ± 1.6	26.0 ± 2.1	78.3 ± 1.8
5e	2-Cl	—CH₃	57.5 ± 1.1	12.7 ± 3.3	75.8 ± 1.1
5f	3-Cl	—CH₃	48.0 ± 2.1	37.7 ± 2.1	81.1 ± 1.6
5g	4-Cl	—CH₃	29.2 ± 1.4	24.6 ± 1.5	69.1 ± 2.1
5h	2,4-di-Cl	—CH₃	26.7 ± 2.0	19.5 ± 1.3	67.2 ± 2.4
5i	4-OC₂H₅	—CH₃	28.9 ± 0.5	42.7 ± 2.6	74.9 ± 1.7
5j	4-F	—CH₃	25.4 ± 0.9	38.2 ± 2.0	68.9 ± 1.5
5k	4-i-Pr	—CH₃	38.9 ± 0.8	43.7 ± 2.1	67.2 ± 1.6
5l	H	—C₂H₅	69.8 ± 1.8	39.1 ± 2.6	88.1 ± 1.5
5m	2-CH₃	—C₂H₅	55.5 ± 1.6	37.1 ± 2.6	84.4 ± 1.9
5n	3-CH₃	—C₂H₅	65.0 ± 3.9	54.9 ± 1.4	88.6 ± 1.2
5o	4-CH₃	—C₂H₅	54.1 ± 0.7	24.2 ± 1.5	83.3 ± 1.5
5p	2-Cl	—C₂H₅	46.6 ± 1.3	50.1 ± 1.2	73.0 ± 2.4
5q	3-Cl	—C₂H₅	56.4 ± 1.8	41.2 ± 2.7	86.2 ± 1.8
5r	4-Cl	—C₂H₅	31.4 ± 1.8	29.5 ± 1.0	75.2 ± 2.1
5s	2,4-di-Cl	—C₂H₅	33.3 ± 0.9	22.1 ± 1.0	72.3 ± 2.1
5t	4-OC₂H₅	—C₂H₅	33.3 ± 0.9	46.9 ± 1.7	70.0 ± 2.3
5u	4-F	—C₂H₅	34.6 ± 1.4	39.3 ± 0.8	78.6 ± 1.2
5v	4-i-Pr	—C₂H₅	50.4 ± 2.2	28.0 ± 2.1	64.8 ± 2.5
Ningnanmycin^b			56.9 ± 0.9	58.3 ± 0.8	92.2 ± 0.9

Synthesis, antiviral activity, and 3D-QSAR study of novel chalcone derivatives containing malonate and pyridine moieties

Abstract

Keywords

Chalcone derivatives

Malonate moiety

Pyridine moiety

Antiviral activity

Cucumber mosaic virus

3D-QSAR

Abbreviations

1 Introduction

2 Experimental

2.1 Materials and methods

2.2 Chemistry

2.2.1 General procedure for synthesizing (E)-3-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-1-(aryl)prop-2-en-1-ones (4a–4k)

2.2.2 General procedure for synthesizing dimethyl (ethyl) 2-(1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-oxo-3-(aryl)phlpropyl)malonates (5a–5v)

2.2.2.1 Dimethyl 2-(1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-oxo-3-phenylpropyl)malonate (5a)

2.2.2.2 Dimethyl 2-(1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-oxo-3-(o-tolyl)propyl)malonate (5b)

2.2.2.3 Dimethyl 2-(1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-oxo-3-(m-tolyl)propyl)malonate (5c)

2.2.2.4 Dimethyl 2-(1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-oxo-3-(p-tolyl)propyl)malonate (5d)

2.2.2.5 Dimethyl 2-(3-(2-chlorophenyl)-1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-oxopropyl)malonate (5e)

2.2.2.6 Dimethyl 2-(3-(3-chlorophenyl)-1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-oxopropyl)malonae (5f)

2.2.2.7 Dimethyl 2-(3-(4-chlorophenyl)-1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-oxopropyl)malonate (5g)

2.2.2.8 Dimethyl 2-(1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-(2,4-dichlorophenyl)-3-oxopropyl)malonate (5h)

2.2.2.9 Dimethyl 2-(1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-(4-ethoxyphenyl)-3-oxopropyl)malonate (5i)

2.2.2.10 Dimethyl 2-(1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-(4-fluorophenyl)-3-oxopropyl)malonate (5j)

2.2.2.11 Dimethyl 2-(1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-(4-isopropylphenyl)-3-oxopropyl)malonate (5k)

2.2.2.12 Diethyl 2-(1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-oxo-3-phenylpropyl)malonate (5l)

2.2.2.13 Diethyl 2-(1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-oxo-3-(o-tolyl)propyl)malonate (5m)

2.2.2.14 Diethyl 2-(1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-oxo-3-(m-tolyl)propyl)malonate (5n)

2.2.2.15 Diethyl 2-(1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-oxo-3-(p-tolyl)propyl)malonate (5o)

2.2.2.16 Diethyl 2-(3-(2-chlorophenyl)-1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-oxopropyl)malonate (5p)

2.2.2.17 Diethyl 2-(3-(3-chlorophenyl)-1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-oxopropyl)malonate (5q)

2.2.2.18 Diethyl 2-(3-(4-chlorophenyl)-1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-oxopropyl)malonate (5r)

2.2.2.19 Diethyl 2-(1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-(2,4-dichlorophenyl)-3-oxopropyl)malonate (5s)

2.2.2.20 Diethyl 2-(1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-(4-ethoxyphenyl)-3-oxopropyl)malonate (5t)

2.2.2.21 Diethyl 2-(1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-(4-fluorophenyl)-3-oxopropyl)malonate (5u)

2.2.2.22 Diethyl 2-(1-(4-((6-chloropyridin-3-yl)methoxy)phenyl)-3-(4-isopropylphenyl)-3-oxopropyl)malonate (5v)

2.3 Antiviral activities against CMV

2.3.1 Purification of CMV

2.3.2 Curative activities of the title compounds against CMV in vivo

2.3.3 Protection activities of the title compounds against CMV in vivo

2.3.4 Inactivation activities of the title compounds against CMV in vivo

2.4 3D-QSAR analysis

2.4.1 Datasets for 3D-QSAR analysis

2.4.2 Molecular modeling and alignment

2.4.3 Partial least-squares analysis

3 Results and discussion

3.1 Chemistry

3.2 Antiviral activity

3.3 Performance of the CoMFA model

4 Conclusion

Acknowledgments

References

Appendix A

Supplementary material

Appendix A

Supplementary material

Supplementary data 1

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