STRUCTURE OF 5-CHLORO-2-METHYLTHIO-3H-INDOL-3-ONE 3-OXIME O-METHYL ETHER

C10H9ClN2OS, M(r) = 240.7 1, monoclinic, C2/c, a = 23.671 (6), b = 5.480 (1), c = 20.644 (8) angstrom, beta = 123.82 (2)-degrees, V = 2225 (1) angstrom3, Z = 8, D(x)= 1.437 g cm-3, lambda(Cu K-alpha) = 1.54178 angstrom, mu = 46.12 cm-1, F(000) = 992, T = 296 K, R = 0.053 for 974 observed [I/sigma(I) greater-than-or-equal-to 3] reflexions. All skeletal atoms in the title oxime ether lie in one plane, including both methyl C atoms, with a mean deviation from the plane of only 0.006 angstrom. The S-methyl group is oriented away from the oxime unit which has E geometry. The structure of the oxime ether, along with a comparison of its UV/VIS absorption spectrum with that of the corresponding oxime and with other 2-methylthio-3H-indol-3-one 3-oximes, demonstrates that the tautomeric equilibrium between 2-methylthio-3H-indol-3-one 3-oxime and 2-methylthio-3-nitrosoindole lies on the side of the former.