Vk. Ahluwalia et al., A CONVENIENT SYNTHESIS OF ,2,3,4-TETRAHYDRO-7H-PYRANO[2,3-D]PYRIMIDIN-7-ONES, Indian journal of chemistry. Sect. B: organic chemistry, including medical chemistry, 34(1), 1995, pp. 51-53
Synthesis of 1, 3-diaryl-6-ethoxycarbonyll, 2, 3, 4-tetrahydro-4-oxo-2
-thioxo-7H-pyrano [2, 3d] pyrimidin-7-ones (4a-e) has been carried out
by the reaction of 5-ureidomethylene-2-thiobarbituric acids (3a-e) wi
th ethyl cyanoacetate in the presence of potassium t-butoxide. Compoun
ds 3a-e in turn have been synthesised by the condensation of 1,3-diary
l-2-thiobarbituric acids (1a-e) with thiourea and triethyl orthoformat
e.