Methyl acetoacetate → 3-Isopropenyl-4-nitro-2(3H)-benzimidazolone

Participants

Reaction Steps

0.3 ml of 47% potassium hydroxide and then 115 mmol of methyl acetoacetate are added to 100 mmol of 2-amino-3-nitroaniline in 50 ml of xylene brought to 120° C. The whole mixture is brought to reflux for 4 hours and the water/methanol mixture formed is removed by means of a Dean and Stark apparatus. 18 ml of 47% potassium hydroxide and 200 ml of water are then added. The aqueous phase is washed with xylene, brought to pH=6 with 12N hydrochloric acid and then extracted with ethyl acetate and the expected product is purified by chromatography on a silica column, using a dichloromethane/methanol (95/5) mixture as eluent.

Provenance & Evidence