Urea → 4-Nitrobenzamide

Participants

Reaction Conditions

Reaction Steps

334 g (2.0 mol) of 4-nitrobenzoic acid, 120 g (2.0 mol) of urea and 2.0 g of phosphorous acid are heated in 1000 ml of mesitylene with stirring at from 158° C. to 163° C. for 8 h. After cooling to 25° C. the solid is filtered off with suction and washed with 200 ml of mesitylene. The filter cake is introduced into 1000 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. 301.2 g of 4-nitrobenzamide are obtained, having a melting point of from 191° to 194° C. This corresponds to a yield of 90.7% of theory. By acidification of the aqueous mother liquor to pH 2, 12.5 g of 4-nitrobenzoic acid (3.7% of theory) are obtained which can be employed again in a subsequent batch.

Provenance & Evidence