Tautomerism in a 2,4-dichlorobenzenesulfonamide derived from 2-amino-4-(2,5-dimethoxyphenyl)thiazole

2,4-Dichloro-N-[2,3-dihydro-4-(2,5-dimethoxyphenyl)thiazol-2-ylidene]benzen esulfonamide, C17H14Cl2N2O4S2, crystallizes in space group P (1) over bar w ith two independent molecules. The structural parameters do not indicate a tautomeric equilibrium but a single imino form. The main differences betwee n the two crystalline forms lie in the intramolecular hydrogen bonding and the relative orientation of the methoxy groups. Attractive intermolecular i nteractions occur and are responsible for the crystalline cohesion.