Fused heterocycles, VI: Reactions of 3-arylidenechromanones and -1-thiochromanones with thiourea
摘要:
Reactions of 3-arylidenechromanones (1-4) and -1-thiochromanones (5-8) with thiourea gave thiazines (9-16) under acidic and pyrimidine derivatives (17-21) under alkaline reaction conditions.
An efficientsynthesis of thiochromeno[3,4-d]pyrimidine derivatives has been achieved successfully via a one-pot three-component reaction of thiochrome-4-one, aromatic aldehyde and thiourea in the presence of 1-butyl-3-methyl imidazolium hydrogen sulphate [Bmim]HSO4. This new protocol has the advantages of environmental friendliness, high yields, short reaction times, and convenient operation. Furthermore