Novel One-Pot Three-Component Synthesis of Fused Dihydropyrimido-Thiadiazole Quinozoline Derivatives of Biological Interest

Abstract

Multi-component one-pot reaction is the simplest and the most economical method for the synthesis of biologically important and pharmacologically active compounds. This reaction process allows the certain of several bonds in a single operation and are attracting increasing attention as one of the most powerful emerging synthetic tools for the reaction of molecular diversity and complexity. The multi component process has proved efficient method for one-pot synthesis of dihydro-thiadiazolo-quinazolin derivatives (2a-h) in excellent yields from thiadiazoles, dimedone and aldehydes under thermal condition without using any catalyst. This environmentally benign procedure for the synthesis of dihydro-thiadiazolo-quinazolin derivatives is suitable for library synthesis and it will find application in the synthesis of biologically active molecules. The process presented here is operationally simple, environmentally benign and has excellent yield. Furthermore, the reaction time is very short within an hour under steam bath reflux condition. The new compounds were screened for antimicrobial activity against various gram-positive, gram-negative bacteria and fungi, during which the compounds depicted good to moderate antimicrobial behavior against S.aureus,B.subti is, P.aeruginosa, E.coi and C.freundii.