反应详情

A solution of 2.8 g (9.232 mmol) of ethyl 5-carbamoyl-4-(4-nitrophenyl)-1H-pyrrole-3-carboxylate in 33.6 cm3 (0.614 mol) of concentrated sulfuric acid is heated at a temperature in the region of 80° C. for 2 hours. The reaction mixture is poured slowly and with stirring into 350 cm3 of ice-water. After stirring for 30 minutes, the reaction mixture is filtered through a No 3 sinter funnel. The solid is washed with 4 times 100 cm3 of ice-water and then dried under reduced pressure (2.7 kPa) at a temperature in the region of 45° C. for 24 hours, to give 2.25 g of 5-carbamoyl-4-(4-nitrophenyl)-1H-pyrrole-3-carboxylic acid in the form of a beige-coloured solid; ES+: m/z=276: [M+H]+; ES−: m/z=274: [M−H]−.

1. additionThe reaction mixture is poured slowly
2. filtrationthe reaction mixture is filtered through a No 3 sinter funnel
3. washThe solid is washed with 4 times 100 cm3 of ice-water
4. customdried under reduced pressure (2.7 kPa) at a temperature in the region of 45° C. for 24 hours