反应详情

A mixture of 2.88 g. (0.02 mole) of 3,4-difluorobenzaldehyde, 3.24 g. (0.025 mole) of propionic anhydride and 0.92 g. (0.02 mole) of sodium propionate under nitrogen is heated at 135° with a magnetic stirrer for 20 hours. The reaction mixture is poured onto 50 ml. of water. A solid precipitates that dissolves when 50 ml. of saturated K2CO3 is added with stirring. The basic solution is extracted with ether (2×100 ml.). The aqueous phase is then poured into an excess of concentrated HCl and ice. The precipitated white solid is filtered and dried to give 3,4-difluoro-α-methylcinnamic acid, M.P. 122°-125°.

1. additionA mixture of 2.88 g
2. additionThe reaction mixture is poured onto 50 ml
3. customA solid precipitates
4. dissolutionthat dissolves when 50 ml
5. additionof saturated K2CO3 is added
6. extractionThe basic solution is extracted with ether (2×100 ml.)
7. additionThe aqueous phase is then poured into an excess of concentrated HCl and ice
8. filtrationThe precipitated white solid is filtered
9. customdried