Sulfuric Acid → 2,3,4,9-Tetrahydro-9-methyl-4-oxo-1H-carbazole-6-carboxamide

Participants

Reaction Steps

A solution of the product of Stage (i) cyanonitrile (2.7 g) in concentrated sulphuric acid (30 ml) was heated at 80° for 1 h. The mixture was poured onto ice (ca. 500 g) to precipitate a solid which was filtered, washed with water (3×50 ml) and dried in vacuo to leave a solid (3.1 g). This was extracted with boiling absolute ethanol (1.5 l), the extract was evaporated to ca 2 ml, diluted with a mixture of chloroform:methanol (1:1, ca 20 ml) and filtered to give the title compound (0.53 g) as a solid m.p. 295°-298°.

Provenance & Evidence