A versatile route to benzodiazocine and spiropyran derivatives through chalcones

Syntheses of 3-(phenyl)-benzo[b]thiophene [2, 3-d][1,2] benzodiazocine derivatives have been accomplished by the reaction of 3-phenacylidine-2-benzo[b]thiophene-2-ones with o -phenylene diamine. The photolytic reaction with trans -stilbene resulted in the exclusive formation of spiro{2′,5′,6′-triphenyl-2H-pyran-4′,3}-benzo[b]thiophene-2-one derivatives. Theoretical calculations have been performed to study the mechanism and stereoselectivity of products. Good yield and broad scope of usable substrates of industrial relevance are other prominent features of the present methodologies. Graphical Abstract Syntheses of 3-(phenyl)-benzo[b]thiophene [2, 3-d][1,2] benzodiazocine derivatives by the reaction of 3-phenacylidine-2-benzo[b]thiophene-2-ones with o-phenylene diamine have been accomplished. A [4+2] photocycloaddition has been carried out to obtain spiro{20,50,60-triphenyl-2H-pyran-40,3}-benzo[b] thiophene-2-one derivatives from 3-phenacylidine-2-benzo[b]thiophene-2-ones and trans -stilbene.