A series of novel chalcone 4a, 4b, 4c, 4d, 4e, 4f, 4g, 4h, 4i, 4j, 4k, 4l and pyrazoline 5a, 5b, 5c, 5d, 5e, 5f, 5g, 5h, 5i, 5j, 5k, 5l derivatives have been synthesized as potential antibacterial agents. The pyrazoline derivatives 5a, 5b, 5c, 5d, 5e, 5f, 5g, 5h, 5i, 5j, 5k, 5l have been synthesized by reaction of various chalcones 4a, 4b, 4c, 4d, 4e, 4f, 4g, 4h, 4i, 4j, 4k, 4l with hydrazine hydrate in the presence of acetic acid. The chalcones 4a, 4b, 4c, 4d, 4e, 4f, 4g, 4h, 4i, 4j, 4k, 4l were prepared by the condensation of key aldehyde 3 with appropriate acetophenone using basic condition and ethanol as a solvent. The key aldehyde 3 has been synthesized by reacting 2‐(chloromethyl)‐3‐methyl‐4‐(2,2,2‐trifluoroethoxy)pyridine hydrochloride and vanillin. The structures of the new compounds were established on the basis of 1H‐NMR, mass, IR, and elemental analysis data. All the newly synthesized compounds were screened for their antibacterial activity against Escherichia coli, Salmonella typhi (Gram‐negative bacteria), Staphylococcus aureus, Micrococcus luteus (Gram‐positive bacteria) and antifungal activity against Candida albicans (fungi).

A series of an easy and efficient route for the synthesis of some new 2-amino-3-cyanopyridine (4a-4i) and 2-methoxy-3-cyanopyridine (5a-5i) derivatives were synthesized through the reaction of various chalcone (3a-3i) with malononitrile in presence of ammonium acetate and sodium methoxide, respectively. The constitutions of the all synthesized compounds have been established by the IR, 1H-NMR, Mass spectral data and Elemental analysis. Furthermore, all the synthesized products were screened for their antimicrobial activity. INRODUCTIONPyridine functionalities have been widely studied [1,2] and widely used [3-6] but still generate much interest due to their wide range of application in medicinal chemistry [7][8][9][10][11]. The naturally occurring B6-vitamins pyridoxine, pyrodoxal, pyridoxamine and codecarbaxylase contain a pyridine nucleus [12]. Pyridine derivatives have been used as herbicides [13] [23]. Most derivatives are prepared by manipulation of pyridine and its simple homologues in a manner similar to chemistry of the benzenoid chemistry. However the simple pyridine compounds are prepared by the cyclization of aliphatic raw materials. The pyridine nucleus is found in a large number of commonly used drugs which have diverse pharmacological activities. Interests in the synthesis of multicyclic pyridine containing compounds have increased in recent years because of their biological and pharmacological activities.The structure of synthesized compounds were assigned based on Elemental analysis, IR 1H-NMR and Mass spectral data. The antimicrobial activity was assayed by using the MIC (Minimum Inhibitory Concentration) method. All the compounds were screened in vitro for their antimicrobial activities against Gram +ve bacteria, Gram -ve bacteria and fungi. The biological activities of the synthesized compounds were compared with known standard drugs. RESULTS AND DISCUSSIONThe synthetic route adopted to obtain the 3-cyanopyridine derivatives 4a-4i and 5a-5i is shown in Scheme 1. 2-Amino-3-cyanopyridine derivatives 4a-4i were prepared from Chalcones 3a-3i by refluxing with malononitrile and ammonium acetate in Ethanol. The isolated product was crystallized with diethyl ether to get 2-amino-3-cyanopyridine derivatives in 58-83% yield. The 2-methoy-3-cyanopyridine derivatives 5a-5i were prepared from Chalcones 3a-3i by refluxing with

ABSTRACT1-Acetyl-3-{4'-[(4'''-chlorophenyl) (phenyl) methyl amino] phenyl}-5-aryl-pyrazolines (3a-3l) and 1-Phenyl-3-{4'-[(4'''-chlorophenyl) (phenyl) methyl amino] phenyl}-5-aryl-pyrazolines (4a-4l) have been synthesized. The products have been assayed for their biological activity against Gram +ve, Gram -ve bacteria and fungi. Some of the compounds showed moderate activity in concentration 50 μg/ml. The structure of the products have been elucidated by IR, 1 H-NMR, mass spectral data elemental analysis and Thin layer chromatography.

Various isopropylacetoacetanilides were treated with 4-(difluoromethoxy)-3-hydroxy benzaldehyde and thiourea/urea in the presence of acid catalyst to produce the 1,4-dihydropyrimidine derivatives (4a-5i and 5a-5i) with good yields. All the synthesized compounds were characterized by mass, 1H-NMR and IR spectrum, also evaluated for antibacterial and antifungal activity against two Gram +ve and two Gram-ve bacterial and fungi strains. The compounds 4e, 4g and 5d were found comparatively promising active against all the bacterial and fungal strains.

A series of an easy and efficient route for the synthesis of some new 2-amino-3-cyanopyridine (4a-4i) and 2-methoxy-3-cyanopyridine (5a-5i) derivatives were synthesized through the reaction of various chalcone (3a-3i) with malononitrile in presence of ammonium acetate and sodium methoxide, respectively. The constitutions of the all synthesized compounds have been established by the IR, 1H-NMR, Mass spectral data and Elemental analysis. Furthermore, all the synthesized products were screened for their antimicrobial activity.