Je. Macor et al., SYNTHESIS AND REACTIVITY OF PYRROLO[3,2-E]INDOLE - REMOVAL OF A N-BOMGROUP FROM AN UNACTIVATED INDOLE, Tetrahedron letters, 38(10), 1997, pp. 1673-1676
A practical synthesis of pyrrolo[3,2-e]indole (1) is described. Differ
ent hydrogenation conditions of the indol-4-ylacetonitrile (3) afforde
d either 1-BOM-pyrrolo[3,2-e]indole (4, 42% from 5-nitroindole) or 1-h
ydroxymethylpyrrolo[3,2-e]indole (5, 46% from 5-nitroindole). Removal
of the benzyl group was found to be problematic, but could be accompli
shed in moderate yield. Treatment bf the resulting 1-hydroxymethylpyrr
olo[3,2-e]indole (5) with NaOH in THF afforded 1 (94% from 5). Limited
studies on the chemistry of 1 are also presented. (C) 1997 Elsevier S
cience Ltd.