O. H. Hishmat

Synthesis and antimicrobial activity of some indole derivatives

Bromination of 2,3-diphenyl-5-methylindole (I) (using 3 mol) with bromine gave the 4,6-dibromo derivative (II) which upon oxidation gave the corresponding 2-benzamido benzophenone derivative (III). Bromination (using 6 mol) with bromine afforded the tetrabromo derivative (IVa) which reated with amines to form the corresponding 5-substituted aminomethyl derivatives (IVb-d). Further bromination ofII using only 1 mol gave the tribromo derivative (Va) which in turn reacted with amines to formVb-g. The antimicrobial activities of compoundsI, IVa, IVc, Va, Ve, Vf andVg were studied.

Synthesis of pyranobenzopyranopyridines and benzodipyran derivatives

6-Formyl-7-hydroxy-5-methoxy-2-methylchromone on bromination yields the 8-bromo derivative or the 8-bromo-6-formyl-5,7-dihydroxy derivative depending on the reaction condition. Cyclization of both leads to the corresponding 3-acetyl-, 3-benzoyl-, 3-carboxamido-, 3-carbethoxybenzodipyran derivatives. The 3-acetylbenzodipyran derivative when treated with ethyl acetoacetate or ethyl cyanoacetate in the presence of ammonium acetate yields the corresponding dihydropyranobenzopyranopyridine dione or the dihydropyranobenzopyranopyridine trione. The reaction of the 3-acetyl derivative with cyanoacetamide in the presence of ammonium acetate affords the substituted pyranobenzopyranopyridine dione. The 3-acetyl derivative undergoes self condensation to form the substituted benzopyranobenzopyran derivative.

SYNTHESIS AND ANTIMICROBIAL ACTIVITY OF SOME BENZOFURAN DERIVATIVES

The Friedel-Crafts acylation of 2,3-diphenyl-5-methylbenzofuran 1a with succinic anhydride gives beta-(2,3-diphenyl-5-methylbenzofuranoyl)propionic acid 1b. Acid 1b reacts with hydrazines yielding the corresponding tetrahydropyridazinones 2. 4,5-Dihydro-1,2-oxazin-6H-6-one 6 is formed by reaction of 1b with hydroxylamine hydrochloride. The reaction of the pyridazinone 2a with dialkyl sulfates, ethyl chloroacetate, Grignard reagents, amines in presence of formaldehyde (Mannich reaction), o-amino-phenol and thiourea has been investigated. The antimicrobial activities of compounds 1a-c, 2a-c, e, f, 4a, b and 5a, b as well as 7b are studied.

Mannich Reaction with 2,3-Bis-(o-methoxyphenyl)-6-benzofuranol.

Das Benzofuranol (I) kondensiert mit Formaldehyd (II) und sekundaren Aminen (III) zu den Mannich-Basen (IV).