p-Toluenesulfonic Acid-Mediated Three-Component Reaction "On-Water" Protocol for the Synthesis of Novel Thiadiazolo[2,3-b]quinazolin-6(7H)-ones

Abstract

The first p-toluenesulfonic acid-mediated "on-water" multicomponent reaction sequence for the synthesis of novel thiadiazolo[2,3-b]quinazolinones from 5-aryl-1,3,4-thiadiazol-2-amines, cyclic 1,3-dicarbonyls and aldehydes with microwave irradiation is described. This protocol proceeds with high atom economy and leads to the generation of three rings, together with one C-C, one C=N and two C-N bonds in a single operation. This new methodology has advantages such as operational simplicity, mild conditions, broad functional group tolerance, simple work-up procedure and applicability on a gram scale. Three to one: The p-toluenesulfonic acid-mediated "on-water" multicomponent reaction sequence for the synthesis of thiadiazolo[2,3-b]quinazolinones is described. The reaction between 5-aryl-1,3,4-thiadiazol-2-amines, cyclic 1,3-dicarbonyls and aldehydes proceeds with microwave irradiation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.