SYNTHESIS AND BIOLOGICAL SCREENING OF SOME NEW HETEROCYCLIS COMPOUNDS

Abstract

The main objective of the studies described in this thesis involved the synthesis of some new classes of heterocyclic quinones, using tetrabromo-Q_-benzoquinone as starting material. These included (the synthesis of seven new types of heterocyclic compounds namely, imidazolo[4,5-f])benzimidazolediones, naphtl1oxazole diones, naphtho­ thiazolediones, benz(b)phenazinediones, carbazoles, pyrrocolines and indoles.

The reaction of tetrabromo-Q-benzoquinone with ammoma solution m a absolute ethanol gave 2,5-diamino-3,6-dibromo-1,4- benzoquinone (1). The latter was reacted with different acid chlorides to give 2,5-diacylamino -3,6-dibromo-1,4-benzoquinone (2).

0

Br Nl

NYBr 0

0

BrnNHCOR

RCOHN Br

()

(l) (2)

Compounds (2) were then reacted with ammonia solution to give the 2,5-diacylamino-3,6-diamino-1,4-benzoquinone (3). The cyclization of (3) to imidazolo[4,5-f]benzoimidazolediones (4a-t) was carried out by heating in ethylorthoformate in presence of concentrated sulphuric acid.