Pentanal → methyl (1RS, 3RS)-cis-1-butyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylate hydrochloride

Beteiligte Stoffe

Reaktionsschritte

A mixture of DL-tryptophan methyl ester hydrochloride (30.49 g), n-valeraldehyde (12.4 g) and methanol (400 ml) is refluxed for 48 hours and then concentrated to about 1/5 volume. After cooling, the precipitates are separated by filtration and recrystallized from methanol to give methyl (1RS, 3RS)-cis-1-butyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylate hydrochloride (20.5 g, 53%), m.p. 218° C. (decomp.) The hydrochloride thus obtained is treated with aqueous ammonia and recrystallized from diisopropyl ether-isopropanol to give the corresponding free base, m.p. 85°-87° C.

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