| abstract |
2,3,3a,4,5,6- hexahydro-8-cyclohexyl- 1H-pyrazino(3,2,1,1-j,k) carbazole hydrochloride of formula (I) is new. (I) is obtd. by alkylation of 6-cyclohexyl-3,4-dihydrocarbazol-1 (2H)-one with beta-(N,N-dibenzylamino)ethyl chloride hydrochloride in a two-phase system comprising an aromatic hydrocarbon and a 30-40% aq. soln. of alkali in the presence of an interphase transfer catalyst at 85-100 deg.C, followed by hydrogenation of the resulting 6-cyclohexyl-9-beta- (N,N-dibenzylamino) ethyl-3,4-dihydrocarbazol -1(2H)-one over a Pd catalyst on a carrier in a higher aliphatic alcohol at 50-70 deg.C and 1-30 atmos. The obtd. 2,3,3a,4,5,6 -hexahydro-8- cyclohexyl-1H-pyrazino(3,2,1-j,k) carbazole is then converted to the hydrochloride. The interphase transfer catalyst is selected from tetra-alkyl-or trialkyl benzyl-, or trialkyl(alkylbenzyl)ammonium halide, or polyethylene glycol, or a mixt. of benzyl chloride and triethylamine or dimethyl formamide. The Pd catalyst comprises Pd bisacetyl acetonate or Pd hydroxide, and the catalyst carrier in C or asbestos. When Pd bisacetyl acetonate is used as catalyst on a carbon carrier the hydrogenation stage is pref. carried out at 50-60 de.gC and at 10-20 atmos. |