Synthesis of Some New Spiro, Isolated and Fused Heterocycles Based on 1H‐indole‐2‐One

TLDR: The reaction of 3-benzoylcyanomethylidine-1(H)-indole-2-one with a variety of active methylene compounds, such as thioglycolic acid, glycine, hydrazine hydrate and phenyl hydrine led to the formation of compounds as discussed by the authors.

Abstract: The reaction of 3-benzoylcyanomethylidine-1(H)-indole-2-one (1) with a variety of active methylene compounds, thioglycolic acid, glycine, hydrazine hydrate and phenyl hydrazine led to the formation of compounds 4a-d-10 3-Thiosemicarbazide-1(H)-indole-2-one 2 on reaction with α-halocarbonyl compounds gave compounds 11a-c, 12a-c The latter compounds on heating with phosphoryl chloride, cyclization takes place via losing water to give the angular tetracyclic compounds 13a,b and 14a-c Cyanoacetic hydrazone derivative 3 readily cyclized upon heating in triethyl orthoformate to give the tricyclic system, oxopyridazino indole 15 On the other hand, the reaction of 3 with benzylidine malononitrile and benzylidene ethylcyanoactate gave the pyranyl hydrazone derivatives 16a,b