Three‐Component Reaction for Construction of Spiro[indoline‐3,7′‐thiazolo[3,2‐a]pyridines] and Spiro[benzo[4,5]thiazolo[3,2‐a]pyridine‐3,3′‐indolines]

Abstract

Abstract The three‐component reaction of thiazole (benzothiazole), dialkyl but‐2‐ynedioate, and isatinylidene malononitriles in toluene at 110–120°C in a sealed tube afforded a mixture of cis/trans ‐isomers of functionalized diastereoisomeric spiro[indoline‐3,7′‐thiazolo[3,2‐a]pyridines] and spiro[benzo[4,5]thiazolo[3,2‐a]pyridine‐3,3′‐indolines] in good yields. Both cis ‐isomers and trans ‐isomers were successfully separated out and fully characterized with spectroscopy and single crystal determination. Under similar conditions, the three‐component reaction containing 2‐(1,3‐dioxo‐1 H ‐inden‐2(3 H )‐ylidene)malononitrile resulted in spiro[indene‐2,7′‐thiazolo[3,2‐a]pyridine] derivatives.