반응 #5466

반응 방정식

dimethyl sulfate

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

sodium methoxide methanol

→

fine colorless needles

수율 87.0%

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

수율 87.0%

용매

water

methanol

반응 조건

후처리

1. 1
   농축concentrated in vacuo
2. 2
   온도refluxed for 2 hours
3. 3
   여과the precipitate was filtered
4. 4
   세척washed with water
5. 5
   기타dried exhaustively in vacuo

실험 절차

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.

출처