Acetic Acid → 2,3,4,5-Tetrahydro-1H-pyrido[4,3-b]indol-1-one

Participants

Reaction Steps

A solution of 5,6-dihydro-4-(2-phenylhydrazino)-2(1H)-pyridinone (8.0 g) in acetic acid (16 ml) was added over 30 min to concentrated sulphuric acid (16 ml) at 10°-20°. The reaction mixture was stirred for 2 h, then added over 10 min to 2N sodium hydroxide (150 ml) at 15°-25°. The solid product was filtered off, triturated with water (50 ml), then recrystallised from ethanol (20 ml) and dried in vacuo to give the title compound (3.79 g), m.p. 255°, t.l.c. (System B, 100:8:1) Rf 0.2.

Provenance & Evidence