The present invention relates to a process for the preparation of asenapine maleate. The process of the present invention involves cyclization of 3-(5-chloro-2-phenoxyphenyl)-l-methylpyrrolidine-2,4-dione (II) to give ll-chloro-2-methyl-2,3-dihydro-lH- dibenzo[2,3:6,7]oxepino[45-C] pyrrol-1-one (III), reduction of compound (III) to give mixture of cis-(3a, 12b)-ll-chloro-2-methyl- 2,3,3a,12b-tetrahydro-lH-dibenzo[2,3:6,7]oxepino[455-C]pyrrol-l-one (IV) and trans-(3a. 12b)-ll-chIoro-2-methyl-2,3,3a,12b- tetrahydro-lH-dibenzo[2,3:6,7]oxepino[4,5-C]pyrrol-l-one (V), enrichment of trans isomer (V) in the mixture by isomerization of the cis isomer (IV), separation of cis isomer (IV) and trans isomer (V), reduction of trans isomer (V) to asenapine free base (VI) and treatment of asenapine free base (VI) with maleic acid.
