Efficient constructions of the four different thienopyrimidinone skeletons via various cyclocondensation of o-aminothienonitrile with carbonyl compounds

A series of new thienopyrimidinone derivatives were synthesized via a novel, straightforward and efficient tandem cyclocondensation of o-aminothienonitrile 1 and carbonyl compounds 2 in different conditions. The synthesized four thienopyrimidinone skeletons were thieno[2,3-d]pyrimidinone 3, tert-hydroxythieno[2,3-d]pyrimidinone 4, symmetrical tetracycle thienothiophenepyrimidone 5 and thienopyrimidine 6 respectively. Their plausible mechanisms were proposed. The properties of compound 5 were investigated.