反应详情

温度

135 °C

A solution was prepared from 100 g of the commercially available hemihydrate of 3-chloro-4-hydroxybenzoic acid in 300 mL of acetic anhydride. After adding 7 drops of concentrated sulfuric acid, the mixture was refluxed at 135° C. for 2 hrs. The product crystallized out on cooling. About 500 mL of cold water was added with stirring, which continued while cooling in an ice/water bath for 1 hr. After filtration and drying, the product was recrystallized from 350 mL of ethyl alcohol to yield 40 g of 3-chloro-4-acetoxybenzoic acid melting at 152-159° C.

1. customThe product crystallized out
2. temperatureon cooling
3. additionAbout 500 mL of cold water was added
4. temperaturewhile cooling in an ice/water bath for 1 hr
5. filtrationAfter filtration
6. customdrying
7. customthe product was recrystallized from 350 mL of ethyl alcohol