Synthesis and antimicrobial activity of some new heterocycles derived from 1-Benzylindole-3-carboxaldehyde

ABSTRACT

1-BENZYLINDOLE-3-CARBOXALDEYDE [1] reacted with 2- cyanoaceto-hydrazide to give the pyrazoline derivative 3. its reaction with 3-amino-5-pyrazolinone either in acidic or basic medium gave pyrazoline derivatives 10 and 11, respectively. reaction of 3 with phosphorus oxychloride yielded the 5-choloropyrazoline derivative 4 which was heterocylized in the reaction with hydrazine hydrate, phenylhydrazine or thiourea to give the condensed pyrazolopyrazoles 6 and 7 and pyrazolopyrimidine 9, respectively. on the other hand, cyclization of 10 with malononitrile and 11 with arylidenemaio-nonitrile gave the corresponding pyranopyrazole derivatives 12 and 17a,b, respectively. Compound 14 was obtained via the reaction of 12 with benzene-sulphonyl chloride. Moreover, pyrazole 18, 19, pyrimidine 20, 21 and pyridine 22, 23 derivatives were prepared through cyclization of 1-benzyl-3-indolylidene malononitrile 13 with different amino compounds. The newly synthesized compounds 3-17 showed in vitro potent antifungal activity only towards Candida albicans at MIC 20 and 25 micro g compared with the reference drug Nystatin which showed MIC at 0.3 micro g. They showed slight activities towards gram-negative and gram positive bacteria under test