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 0.015 (2) and 0.020 (2) Å for the methyl C atoms in the methyl acetate substituents and 0.033 (1) Å for the linked C atom of the benzothia-zole substituent. The S, C and N atoms in the thia-zole ring of the benzothia-zole substituent lie -0.037 (2), 0.046 (2) and -0.028 (2) Å, respectively, from the mean plane defined by the benzene ring atoms.