Original scientific paper

Indole Compounds. VI. Syntheses of Indole Thioethers by Direct Cyclization of Phenylhydrazine Hydrochlorides and Aliphatic Acetals Under Mild Conditions

D. Keglević ; Tracer Laboratory, Institute »Ruder Boskovic«, Zagreb, Croatia, Yugoslavia
D. Goleš ; Tracer Laboratory, Institute »Ruder Boskovic«, Zagreb, Croatia, Yugoslavia

Abstract

The ease of Fischer indolization, into several types of indole
thioethers, with respect to the nature of the starting arylhydrazine
and acetal components in 25°/o acetic acid at 80° is investigated.
3-Benzyloxy- and 3,4-dimethyl-phenylhydrazine hydrochlorides
indolize with 4-benzylthiobutanal diethyl acetal into isomeric
mixtures of 4- and 6-benzyloxy-, and 4,5- and 5,6-dimethyl-3-
(2-benzylthioethyl) indoles (I and II, and III and IV, respectively);
separation and structure assignment of the isomers is reported.
Debenzylation of III and IV gives the corresponding 3-(2-mecaptoethyl)- and bis[3-(2-thioethyl)indoles]. Indolization of 3-benzylthiopropanal diethyl acetal with several arylhydrazine hydrochlorides results in the formation of the corresponding 3-benzylthiomethylindoles in low yield; a subsequent decomposition of
the products under the conditions of the indolization reaction
has been established. 4-Benzylthiophenylhydrazine hydrochloride
and 4-aminobutanal diethyl acetal cyclize smoothly into 5-benzylthiotryptamine
hydrochloride.

Keywords

Hrčak ID:

197518

URI

https://hrcak.srce.hr/197518

Publication date:

10.2.1971.

Visits: 877 *