PROCESS FOR PREPARING ENTACAPONE SUBSTANTIALLY FREE OF Z-ISOMER, SYNTHESIS INTERMEDIATES THEREOF AND A NEW CRYSTALLINE FORM

摘要

The present invention relates to a new process for preparing Entacapone s ubstantially free of Z-isomer from 3, 4-dihydroxy-5-Nitrobenzaldehyde and N, N-Dimethylcyano acetamide, or directly from a mixture of (E) - and (Z) - is omers of Entacapone, by formation of organic or inorganic salts, specially p iperidine and sodium ones. A new crystalline form G of Entacapone can be obt ained from this method in a fast, efficient, and simple way and substantiall y free of Z-isomer. Another object of the invention is a pharmaceutical comp osition comprising it.