2-Naphthylamine → 1H-benzo[e]indole-1,2(3H)-dione

Participants

Reaction Conditions

Reaction Steps

A mixture of 2-naphthylamine (8.0 g, 56 mmol) in glacial acetic acid (500 mL) was treated with diethyl ketomalonate (9.2 mL, 62 mmol), heated to 120° C. for 4 hours, and concentrated. The concentrate was suspended in a solution of KOH (36.8 g, 690 mmol) in water (736 mL) and stirred overnight with a stream of air blowing into the solution. The resulting mixture was filtered and the filtrate was adjusted to approximately pH 3 with concentrated HCl. The resulting suspension was cooled to 0° C. and filtered. The filter cake was dried under vacuum to provide the desired product (8.76 g, 79%). MS (DCI) m/e 198 (M+H)+, 215 (M+NH4)+.

Provenance & Evidence