Ethyl 1,3,4,5-tetrahydro-2H-pyrido[4,3-b]indole-2-carboxylate → HCID 44593836, compound

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Reaction Conditions

Reaction Steps

A mixture of ethyl 1,3,4,5-tetrahydro-2H-pyrido[4,3-b]indole-2-carboxylate (49.2 g), prepared as described in J. Med. Chem. 23:635-643 (1980), in NH3 /CH3OH (400 ml) was hydrogenated with Raney nickel (5 g) as a catalyst. The mixture was cooled and the catalyst was filtered off. The filtrate was evaporated. The residue was dissolved in anhydrous diethyl ether (600 ml) and HCl(g) was allowed to bubble through the solution for 30 minutes. The resulting precipitate was filtered off, dissolved in water (200 ml) and extracted with diethyl ether (100 ml). The organic layer was separated, dried, filtered and the solvent was evaporated. The residue was solidified in DIPE (150 ml), cooled to 0° C., filtered off and dried, yielding 34.3 g (70%) of (±)-ethyl cis-1,3,4,4a,5,9b-hexahydro-2H-pyrido[4,3-b]indole-2-carboxylate (intermediate 1).

Provenance & Evidence