Tryptamines, Carbolines, and Related Compounds. Part II.
A Convenient Synthesis of Tryptamines and ?-Carbolines.R. A. Abramovitch and D. ShapiroJ. Chem. Soc. 4589-4592 (1956)
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https://www.thevespiary.org/rhodium/Rhodium/pdf/tryptamines.abramovitch-2.pdf)
Abstract2,3-Dioxopiperidine 3-phenylhydrazone was cyclised under acid conditions to 1,2,3,4-tetrahydro-1-oxo-?-carboline. This was hydrolysed to tryptamine-2-carboxylic acid which was decarboxylated to tryptamine. The same reaction sequence with p-anisidine afforded a new route to serotonin. 5-Benzyloxytryptamine-2-carboxylic acid could not be decarboxylated to the base. The method also provides a route to the 1,2,3,4-tetrahydro-?-carbolines.
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Tryptamines, Carbolines, and Related Compounds. Part III.
1-Methyl- and 1,N-Dimethyl-tryptaminesR. A. AbramovitchJ. Chem. Soc. 4593-4602 (1956)
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https://www.thevespiary.org/rhodium/Rhodium/pdf/tryptamines.abramovitch-3.pdf)
AbstractThe scope of the synthesis of tryptamines from 1,2,3,4-tetrahydro-1-oxo-?-carbolines has been examined. Substituents in the benzene ring affect the ease of decarboxylation of the tryptamine-2-carboxylic acids, in the order OMe > Me > H > Cl > NO
2; an explanation is suggested. Tetrahydro-oxocarbolines with dimethyl sulphate give the 9-methyl compounds from which the 1-methyltryptamines can be obtained; the amide group is unreactive but can be methylated by prolonged treatment with sodium hydride followed by methyl iodide, to give the 2,9-dimethyl compound in which the amide group now behaves normally, though it is resistant to alkaline hydrolysis. Acid hydrolysis leads to N,N'-dimethyltryptamine. Cyclisation of 2,3-dioxopiperidine 3-m-methoxyphenylhydrazone by formic acid gives a mixture of isomers, whereas ethanolic hydrogen chloride gives only the 7-methoxy-compound which, contrary to report, is hydrolysed normally to the amino-acid.