Synthesis of pharmacologically active indoles

Formylation of 6-methoxy-1-methyl and 5-methyl,2,3-diphenyl-1H-indole (Ib and IX) gave the 5- and 6- carboxaldehyde derivatives (II and X) respectively, which were treated with ethyl cyanoacetate to form the corresponding 2-cyano-3-substituted acrylic acid ethyl ester (III and XI). The latter compounds reacted with hydrazine hydrate, urea and thiourea to form the corresponding 5-amino-4-substituted 2,4,dihydropyrazol-3- one (IV), 6-indolyl-2,4-dioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitrile s (V and XII) and 6-indolyl-4-oxo-2-thixo-1,2,3,4-tetrahydropyrimidine-5-ca rbonitriles (VI and XIII). Reaction of the 5- and 6-carboxaldehyde derivatives with malononitrile afforded the 2-substituted malononitrile derivatives (VII and XIV). VII and XIV reacted readilly with aromatic ketones to give the 2-amino4,6-disubstituted nicotinonitriles (VIII a,b and XVa,b). The biological activity of compounds Ia, Ib, II, III, IX and X was tested for antiinflammatory, ulcerogenic and antispasmodic activities.