反应详情

A mixture of 10 g. 4-hydroxy-3-chlorobenzoic acid and 50 ml. of acetic anhydride is refluxed for two hours. Excess acetic anhydride is distilled under vacuum and the residue diluted and stirred with a mixture of methanol (100 ml.) and water (20 ml.) at about 50° for 30 minutes. The mixture is then reduced to low volume under vacuum, water added and the precipitated crystals filtered. Recrystallization from toluene gives 6.5 g. (52% yield) m.p. 162°-163° C.

1. additionA mixture of 10 g
2. distillationExcess acetic anhydride is distilled under vacuum
3. additionthe residue diluted
4. additionadded
5. filtrationthe precipitated crystals filtered
6. customRecrystallization from toluene
7. customgives 6.5 g