反应 #6857

反应方程式

hydrochloric acid

4-methoxyphthalic acid dimethyl ester

sodium hydroxide

→

5-methoxy-isobenzofuran-1,3-dione

收率 50.8%

溶剂

methanol

反应条件

后处理

1. 1
   温度to reflux for 3 hours
2. 2
   萃取extracted three times with ethyl acetate
3. 3
   萃取The organic extractions
4. 4
   干燥dried over magnesium sulfate
5. 5
   workup.DISSOLUTIONThe diacid (1.43 g) and 1.9 mL of acetic anhydride were dissolved in tetrahydrofuran
6. 6
   温度heated
7. 7
   温度to reflux for 16 hours
8. 8
   其他The solvent was evaporated

实验过程

A solution of 4-methoxyphthalic acid dimethyl ester (3.1 g, Fluka, U.S.A.) in 10 mL methanol and 35 mL of a 1 M solution of aqueous sodium hydroxide was heated to reflux for 3 hours. The solution was allowed to cool to rt, acidified to pH 2 with 1 M hydrochloric acid, and extracted three times with ethyl acetate. The organic extractions were combined, dried over magnesium sulfate, and reduced in vacuo to cleanly yield 2.43 g of the corresponding diacid. The diacid (1.43 g) and 1.9 mL of acetic anhydride were dissolved in tetrahydrofuran and heated to reflux for 16 hours. The solvent was evaporated to give 5-methoxy-isobenzofuran-1,3-dione (1.25 g).

来源