Dimethyl 3-acetyl-3-(1,3-benzothia-zol-2-yl)penta-nedioate.

The title compound, C(16)H(17)NO(5)S, was one of two condensation products from the reaction of 1-(1,3-benzothia-zol-2-yl)propan-2-one with methyl chloro-acetate. The non-H atoms in each of the four substituent groups on the central quaternary C atom are virtually coplanar. The maximum deviations from the least-squares planes are 0.