Process for preparing 3-amino-9,13b-dihydro-1H-dibenz(c,f)imidazo(1,5-a)azepine-hydrochloride

A process for preparing 3-amino-9,13b-dihydro-1H-dibenz[c,f]imidazo[1,5-a]azepine-hydrochloride, which comprises:

• a) hydrogenating 6-phthalimidomethyl-5H-dibenz[b,e]-azepine i) in dimethylformamide and 0.5 to 5 mol/mol of formic acid, or ii) in dimethylacetamide and 0.5 to 5 mol/mol of acetic acid, in the presence of palladium/charcoal, at 1 to 10 bar of hydrogen pressure and at a temperature of 40.degree. to 100.degree. C., to produce 6-(phthalimidomethyl)-6,11-dihydro-5H-dibenz[b,e]azepine;
• b) reacting the 6-(phthalimidomethyl)-6,11-dihydro-5H-dibenz[b,e]azepine with hydrazine in an alkali metal hydroxide to produce 6-aminomethyl-6,11-dihydro-5H-dibenz[b,e]azepine;
• c) reacting the 6-aminomethyl-6,11-dihydro-5H-dibenz[b,e]azepine with bromocyanogen produced in situ to produce a reaction mixture;
• d) adding a base selected from the group consisting of N,N-dibenzylamine, N,N-dibutylamine, diethanolamine, diisopropylamine, N-ethylbenzylamine, sarcosin-Na salt and N-methylbenzylamine to the reaction mixture, to produce 3-amino-9,13b-dihydro-1H-dibenz[c,f]imidazo[1,5-a]azepine;
• e) dissolving the 3-amino-9,13b-dihydro-1H-dibenz[e,f]imidazo[1,5-a]azepine in a solvent selected from the group consisting of benzene, xylene, tolune and a halobenzene;
• and then adding a sodium hydroxide solution to effect precipitation;
• f) dissolving the precipitate produced in e) in dimethylformamide comprising from 2 to 7 wt. -% hydrochloric acid gas to produce a solution;
• and
• g) removing approximately one third of the dimethylformamide from the solution produced in f) by filtration and distillation, and then cooling the remainder of the solution to produce 3-amino-9,13b-dihydro-1H-dibenz[c,f]imidazo[1,5-a]azepine-hydrochloride.