Synthesis of 1,2,3,4-Tetrahydro-β-carbolines

Abstract

1,1-Disubstituted 1,2,3,4-tetrahydro-β-carbolines are formed by the action of trifluoroacetic acid on enamines derived from tryptamine or tryptophan. With methanolic hydrogen chloride, either cyclization to the corresponding β-carboline derivative, or acidolysis to regenerate the parent amine, occurs. The course of this reaction depends on the substitution pattern. Mixtures of products are not formed. Authentic phenacyl L-tryptophanate hydrochloride has been synthesized.