Organic Synthesis International: 1

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Wednesday 5 October 2016

A Rapid microwave assisted synthesis of novel 1,4-dihydropyridines derivatives under aqueous medium

July-August 2012, Volume 2, No.4

July-August 2012, Volume 2, No.4
Chemistry & Biology Interface, 2012, 2, 4, 206-257
(ISSN: 2249 – 4820)

A Rapid microwave assisted synthesis of novel 1,4-dihydropyridines derivatives under aqueous medium
Shailesh Thakrar, Dhairya Bhavsar, Vicky Jain, Anamik Shah

Chemistry & Biology Interface, 2012, 2, 4, 220-227 pg 220-227, Department of Chemistry, Saurashtra University, Rajkot-360005, India

[Full Text-PDF]

Keywords: 1, 4-dihydro pyridines, Pyrazole aldehyde, One-pot, Microwave, Aqueous medium,
Fe+3 montmorillonite clay K-10, HY-zeolite.
Abstract: An environment friendly synthesis of 1,4-dihydropyridine derivatives was developed by one pot multi component reaction of pyrazole aldehyde, EAA/MAA, 3-amino crotononitrile and Fe+3 montmorillonite clay K-10/ HY-zeolite under microwave irradiation in aqueous medium. The structures of all synthesized compounds were well characterized by Mass, FT-IR, 1H NMR and elemental analysis.

Methyl 5-cyano-1,4-dihydro-2,6-dimethyl- 4-(1,3-diphenyl-1H-pyrazol-4-yl)pyridine- 3-carboxylate (5a): MP: 182-184 oC; IR (cm-1): 3489, 3367, 3198, 2974, 2897, 2332, 2260, 1707, 1660, 1587, 1519, 1435, 1356, 1282, 744, 688. MS: m/z = 426.17; 1H NMR (DMSO-d6) δ ppm: 2.14(s, 6H), 2.58(s, 3H), 4.91(s, 1H), 6.91-6.99(d, 2H), 7.20-7.22(t, 2H), 7.29-7.31(t, 1H), 7.45-7.49(t, 2H), 7.60-7.62(d, 1H), 7.71-7.73(d, 2H), 7.95(s, 1H), 8.74(s, 1H). MS: m/z: 410.17; Anal. Calcd. for C25H22N4O2: C, 73.15; H, 5.40; N,13.65; O,7.80; Found: C, 73.06; H, 5.36; N, 13.61; O,7.79(%).

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Sunday 18 September 2016

Synthesis and Antifungal Activity Against Candida Strains of Mesoionic System Derived From 1,3-Thyazolium-5-thiolate

General procedure for the preparation of ten newly synthetized compounds - 2-(p-chlorophenyl)-3-methyl-4- (p-isopropylphenyl)-1,3-thiazolium-5-(N-arylacetamide)thio chloridrates 7a-j Mesoionic 2-(p-chlorophenyl)-3-methyl-4-(pisopropylphenyl)-1,3-thiazolium-5-thiolate 5 (278 mmol) was dissolved in hot ethanol and then 2-chloro-Narylacetamides 6a-j (278 mmol) were added. The system was refluxed for 4 h and then concentrated at reduced pressure, giving a yellow-orange solid.

R1, R2 =H, H

2-(p-Chlorophenyl)-3-methyl-4-(p-isopropylphenyl)-1,3- thiazolium-5-(N-phenylacetamide)thio chloridrate 7a Yield: 92.13%;

m.p.: 130-132 °C; anal. calcd.: C, 60.58; H, 4.69; N, 5.43; S, 12.44; found: C, 60.60; H, 4.70; N, 5.42; S, 12.42;

IR (KBr) νmax / cm-1 3181 (NH), 3003 (CHAr.), 2958 (CHAlif.), 1680 (C=O), 1599, 1551, 1491 (C=C and C=N of aromatic and heterocyclic rings), 1442 (C–N of N–CH3), 1404 (C–N), 1092 (C–Cl), 1001, 922 (CHAr.), 756 (NH), 557, 537 (C–C);

1 H NMR (200 MHz, CDCl3) delta
1.30 (d, 6H, J 6.9 Hz, H-16, H-16’),
2.98 (sept, 1H, H-15), 3.79 (s, 2H, H-17),
3.84 (s, 3H, H-10), 7.09 (t, 2H, J 7.3 Hz, H-23),
7.28-7.34 (m, 4H, H-13, H-13’, H-21, H-25),
7.60 (d, 2H, J 8.1 Hz, H-8, H-8’),
7.73 (d, 2H, J 7.9 Hz, H-12, H-12’),
7.86-7.93 (t, 4H, J 7.3 Hz, H-7, H-7’, H-22, H-24),
11.02 (s, 1H, H-19);

13C NMR (50 MHz, CDCl3)
delta 170.21 (C-2), 166.81 (C-18), 152.68 (C-14),
140.28 (C-4), 138.93 (C-9), 132.04 (C-20), 131.64 (C-7, C-7’), 130.89 (C-12, C-12’),
130.27 (C-8, C-8’), 128.69 (C-22, C-24), 127.54 (C-13, C-13’),
124.09 (C-23), 123.79 (C-11), 123.59 (C-6),
120.28 (C-21, C-25), 42.24 (C-17), 40.92 (C-10), 34.21 (C-15), 23.76 (C-16, 16’).

Peixoto IN, Souza HDS, Lira BF, Silva DF, Lima EO, Barbosa-Filho JM, et al. Synthesis and Antifungal Activity AgainstCandida Strains of Mesoionic System Derived From 1,3-Thyazolium-5-thiolate. J. Braz. Chem. Soc. 2016;27(10):1807-1813

*e-mail: athayde-filho@quimica.ufpb.br
J. Braz. Chem. Soc. 2016, 27(10), 1807-1813

Synthesis and Antifungal Activity Against Candida Strains of Mesoionic System Derived From 1,3-Thyazolium-5-thiolate

Isabelle N. Peixoto; Helivaldo D. S. Souza; Bruno F. Lira; Daniele F. Silva; Edeltrudes O. Lima; José M. Barbosa-Filho; Petrônio F. de Athayde-Filho

Ten new mesoionic derivatives from the 1,3-thiazolium-5-thiolate system with substituted acetamides were synthesized, had their potential as new drug evaluated in an in silico study and in their activity as antifungal against strains of Candida albicans.