反应详情

48.5 g (0.27 mol) of 3-allyloxy-4-hydroxy-benzaldehyde, 104 g (1 mol) of malonic acid, 140 ml of pyridine and 4 ml of piperidine are heated to 100° C. for 2 hours, whilst stirring. The volatile constituents are distilled off under reduced pressure at 80° C. and the residue is stirred with 800 ml of water. The crystals obtained are filtered off and recrystallised from methylene chloride. 3-Allyl-4hydroxy-cinnamic acid of melting point 132°-133° C. is obtained.

1. distillationThe volatile constituents are distilled off under reduced pressure at 80° C.
2. stirringthe residue is stirred with 800 ml of water
3. customThe crystals obtained
4. filtrationare filtered off
5. customrecrystallised from methylene chloride