反应详情

A solution of 156 g of methyl 3-cyano-2,4,5-trifluoro-benzoate in 960 ml of glacial acetic acid, 140 ml of water and 69 ml of concentrated sulphuric acid is heated to reflux for 8 hours. The acetic acid is then largely removed by distillation in vacuo and the residue is treated with water. The precipitated solid is filtered off with suction, washed with water and dried. 118.6 g of 3-cyano-2,4,5-trifluoro-benzoic acid are obtained as a white solid of melting point 187-190° C.

1. temperatureto reflux for 8 hours
2. customThe acetic acid is then largely removed by distillation in vacuo
3. additionthe residue is treated with water
4. filtrationThe precipitated solid is filtered off with suction
5. washwashed with water
6. customdried