CONVERSION OF TRANS-TO CIS-N,N-DIMETHYL-9-(3-(4- METHYL-1-PIPERAZINYL)PROPYLIDENE) THIOXANTHENE-2- SULFONAMIDE AND RECOVERY OF THE CIS-ISOMER

摘要

Trans-N,N-dimethyl-9-3-(4-methyl-1-piperazinyl)propylidene!-thioxanthe ne-2-sulfonamide is isomerized to the cis-isomer by contacting the trans-isomer with strong base in a polar organic solvent. By using an organic solvent in which the solubility of the cis-isomer is substantially less than that of the trans-isomer, the cis-isomer can be selectively precipitated from said solvent, thereby favoring additional isomerization to the cis-isomer in the supernatant, and separated.