Synthesis of (4S*,5S*)-diphenyl-1,3,4,5-tetrahydro-2H-[1]benzopyrano[4,3-d]pyrimidine-2-thiones by base-catalysed cyclocondensation of (E)-3-benzylideneflavanones with thiourea, and determination of their monoacetylation site

Mallik A., Chattopadhyay F., Dey D., Patra A., Elmali A.

JOURNAL OF CHEMICAL RESEARCH, no.3, pp.180-182, 2004 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Publication Date: 2004
  • Journal Name: JOURNAL OF CHEMICAL RESEARCH
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.180-182
  • Keywords: flavanones, thiourea, fused [1]benzopyrans, fused pyrimidinethiones, E-3-BENZYLIDENEFLAVANONES
  • Ankara University Affiliated: No

Abstract

Base-catalysed cyclocondensation of (E)-3-benzylideneflavanones with thiourea has been found to be highly stereoselective, producing (4S*,5S*)-diphenyl-1,3,4,5-tetrahydro-2H-[l]benzopyrano[4,3-d]pyrimidine-2-thiones in high yield, the structure of one of which has been determined by X-ray crystallography. Just like 4,6-diaryl-3, 4-dihydropyrimidine-2(1H)-thiones, the said products also undergo monoacetylation on treatment with Ac2O. The site of acetylation in both of these classes of compound are established by detailed NMR spectral studies.