5-[(4-Methyl-phen-yl)sulfon-yl]-1-phenyl-thio-pyrano[4,3-b]indole-3(5H)-thione di-chloro-methane monosolvate.

Rhodium-catalyzed [2+2+2] cyclo-addition of carbon di-sulfide to o,N-dialkynyl-tosyl-anilines gives two isomeric indolo-thio-pyran-thio-nes, a violet and a red isomer. This is the first crystal structure of a red isomer, which crystallizes with one solvent mol-ecule of di-chloro-methane in the asymmetric unit, C24H17NO2S3·CH2Cl2. In the extended structure, centrosymmetric pairs of the planar annulated system are arranged in strands and solvent mol-ecules fill the space between the strands.