6'-(4-Chlorophenyl)-spiro[cyclohexane-1,2'-thieno[3,2-d][1,3] oxazin]-4'(1'H)-one (1) was synthesized and used as a starting material for the synthesis of a novel series of spiro compounds having biologically active sulfonamide 2a-e and 3'-(4-acetylphenyl)-6'- (4-chlorophenyl)-1'H-spiro[cyclohexane-1,2'-thieno[3,2-d] pyrimidine-4'(3'H)-one (3). Compound 2a was used as a key intermediate for the...

An efficient and simple one-pot approach for the synthesis of 3,4-dihydropyrimidin-2-(1H)-one derivatives using antimony trichloride (SbCl3) as a mild catalyst by means of three-component Biginelli reaction between β-keto esters, aldehyde derivatives and urea/thiourea under thermal and solvent-free conditions with excellent yields and short reaction times is reported. This m...