Urea → 4-Nitrobenzamide

Participants

Reaction Conditions

Reaction Steps

83.5 g (0.5 mol) of 4-nitrobenzoic acid, 33.0 g (0.55 mol) of urea and 0.5 g of phosphorous acid are heated in 250 ml of o-chlorotoluene with stirring at from 150° to 157° C. for 8 h. After cooling to 25° C. the solid is filtered off with suction and washed with 50 ml of o-chlorotoluene. The filter cake is introduced into 250 ml of water, the mixture is adjusted to a pH of 12 using aqueous sodium hydroxide solution, and is subjected to steam distillation. Subsequently the solid is filtered off with suction and dried at 100° C. 74.9 g of 4-nitrobenzamide are obtained having a melting point of from 194 to 195° C. This corresponds to a yield of 90.3% of theory. By acidification of the aqueous mother liquor to pH 2, 3.4 g of 4-nitrobenzoic acid (4.1% of theory) are obtained which can be employed again in a subsequent batch.

Provenance & Evidence