p-Toluenesulfonic acid monohydrate → 3-(4-nitrophenyl)-1H-pyrrole-2-carboxamide

Participants

Reaction Conditions

Reaction Steps

To 1.96 g (5.139 mmol) of 2-(2,4-dimethoxybenzylamino)carbonyl-3-(4-nitrophenyl)-1H-pyrrole dissolved in 55 cm3 of toluene are added, at a temperature in the region of 20° C. under an argon atmosphere, 2.224 g (11.69 mmol) p-toluenesulfonic acid monohydrate. After stirring for 4.5 hours at a temperature in the region of 65° C., the reaction mixture is diluted with 70 cm3 of ethyl acetate and then washed successively with three times 50 cm3 of water and 50 cm3 of saturated aqueous sodium chloride solution. The resulting organic phase is dried over anhydrous magnesium sulfate, filtered and concentrated to dryness under reduced pressure (2.7 kPa) to give a yellow solid, which is then stirred in 15 cm3 of acetonitrile for 16 hours. After filtering through a No. 3 sinter funnel, the solid is washed with twice 4 cm3 of ice-cold acetonitrile and then dried under reduced pressure (2.7 kPa) at a temperature in the region of 35° C. for 5 hours to give 0.5 g of 3-(4-nitrophenyl)-1H-pyrrole-2-carboxamide in the form of an ochre-coloured solid; EI: m/z=231: M+ base peak; m/z=214 [M−NH3]+; m/z=184 [M-HNO2]+.

Provenance & Evidence