| abstract |
A novel process for the preparation of the (Z)-isomer of 1,2-diphenyl-1-[p-(2-dimethylaminoethoxy)phenyl]but-1-ene from the mixture of the (Z)- and (E)-isomers is indicated. The (Z)-isomer is used in medicine for the treatment of breast cancer. The process starts from the isomer mixture and leads via salt formation, crystallisation of the acid addition salts of the (Z)-isomer, liberation of (Z)-1,2-diphenyl-1-[p-(2-dimethylaminoethoxy)- phenyl]but-1-ene from the salts and, if desired, reaction carried out to give a physiologically tolerable acid addition salt. It is characteristic of the invention that, for salt formation, dibenzoyl-d-tartaric acid monodimethylamide is used and the resulting (Z)-1,2-diphenyl-1-[p-(2-dimethylaminoethoxy)phenyl]but-1-ene dibenzoyl-d-tartaric acid monomethylamide salt is recrystallised from an organic solvent medium. The process allows the pharmacologically useful (Z)-isomer to be separated from the isomer mixture without fractional crystallisation. The yield of the process is better than that of the previously known processes, and the product obtained is additionally purer. |