The title compound, C(19)H(17)ClN(2)O(5)S, was synthesized by the reaction of ethyl 6-(4-chloro-phen-yl)-2-mercapto-4-methyl-1,6-dihydro-pyrimidine-5-carboxyl-ate and dimethyl acetyl-ene-dicarboxyl-ate in methanol. In the mol-ecule, the nearly planar thia-zole ring, with a mean deviation from the plane of 0.0108 (3) Å, is fused with a dihydro-pyrimidine ring in a flattened half-chair conformation.