Mv. Vasylyev et al., A facile method for synthesis of heterocycles containing tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidine and coumarin moieties, HETEROCYC C, 5(3), 1999, pp. 241-242
2-(2-Oxo-2H-1-benzopyran-3-yl)-5,6,7,8-tetrahydro-3H-benzo(4,5)thienol[2,3-
d]pyridimin-4-ones (4a,b) have been synthesized via a rearrangement of 2-(N
-3-carbamoyl-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl)imino-2H-1- benzopyran
-3-carboxamides (3a,b), The tetrahydrobenzo[b]thiophenes 3 have been conven
iently prepared by the reaction of 2-imino-2H-1-benzopyran-3-carboxamides (
1a.b) with 2-amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3carboxamide (2) in
glacial acetic acid.