PROCESS FOR THE SYNTHESIS OF A BENZAMIDE DERIVATIVE

摘要

The invention relates to a process for the synthesis of mosapride citrate of formula (I), the chemical name: (R,S)-4-amino-5-chloro-2-ethoxy-N-{ [4-(4-fluoro-benzyl)-2­ morpholinyl]-methyl}benzamide citrate dihydrate, (I), (II) reacting the compound of formula (II) with di-tert-butyl-dicarbonate in an alcohol in the presence of a base, the obtained product is ethylated in an inert solvent in the presence of a base, the obtained compound is hydrolyzed with an alkyl-hydroxide and the obtained salt neutralized with an acid, the obtained product is chlorinated, and the obtained compound of formula (VI) is reacted with the compound of formula (VII), (VI), (VII) where BOC is tert-butoxy-carbonyl protecting group and removing the protecting group from the obtained compound of formula (VIII) the mosapride base is prepared, (VIII) where BOC is defined as above and in desired case with an acid, preferably with citric acid a pharmaceutically acceptable salt, preferably the mosapride citrate dehydrate of formula (I) is produced.