Synthesis and Antimicrobial Screening 6-Aryl-2-(Amino/Methoxy)-4-[(4′-Difluoro Methoxy) (3′-Hydroxy) Phenyl] Nicotinonitrile

Abstract

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

Synthesis, characterization and antibacterial evaluation of novel 2-mercaptobenzothiazole derivatives bearing 2-aminonicotinonitrile moiety

“…Reaction mixture was refluxed at 60 °C for 8 hours, poured into crushed ice water, the product was extracted with 20 mL ethyl acetate. The organic layer was washed with brine, dry over sodium sulphate and evaporated under reduced pressure [29].…”

Recent Progress on Nicotinonitrile Scaffold‐based Anticancer, Antitumor, and Antimicrobial Agents: A Literature Review

“…made two series of 2‐aminonicotinonitriles 207a – i and 2‐methoxynicotinonitriles 208a – i from chalcones 206a – i by refluxing with ammonium formate and malononitrile in ethanol and/or sodium methoxide in ethanol for 8–12 h, respectively. The antimicrobial activity of 207a – i and 208a – i has been investigated and revealed that most of the tested compounds have moderate antibacterial activity with minimum inhibitory concentrations within 20 and 80 μg/mL and low antifungal activity (Scheme ) .…”