反应 #5466

反应方程式

dimethyl sulfate

4-amino-5-chloro-2-hydroxybenzoic acid

sodium methoxide methanol

→

fine colorless needles

收率 87.0%

4-Amino-5-chloro-2-hydroxybenzoic acid, methyl ester

收率 87.0%

溶剂

water

methanol

反应条件

后处理

1. 1
   浓缩concentrated in vacuo
2. 2
   温度refluxed for 2 hours
3. 3
   过滤the precipitate was filtered
4. 4
   洗涤washed with water
5. 5
   其他dried exhaustively in vacuo

实验过程

A solution of 4-amino-5-chloro-2-hydroxybenzoic acid (1.88 g, 10 mmol) in absolute methanol (20 mL) was treated with 25% sodium methoxide/methanol (2.16 g, 10 mmol), stirred for 30 minutes, and concentrated in vacuo. The solid residue was taken up in anhydrous acetone (30 mL), treated with dimethyl sulfate (1.64 g, 13 mmol), and refluxed for 2 hours. The resultant solution was diluted with water (100 mL), and the precipitate was filtered, washed with water, and dried exhaustively in vacuo to afford 1.75 g (87%) of fine colorless needles. The material was recrystallized from ethyl acetate/hexane; mp 138°-139° C.

来源