反应详情

Concentrated sulphuric acid (20 ml) was added to a suspension of 2-chloro-4-(N-methylsulphonylamino)benzoic acid (10.3 g) in methanol and the mixture was stirred and heated at reflux for 22 hours. It was cooled, evaporated to dryness and diluted with water, extracted with ethyl acetate, washed with aqueous sodium bicarbonate solution, water, dried (MgSO4) and filtered. The filtrate was evaporated to dryness to give methyl 2-chloro-4(N-methylsulphonylamino)benzoate(10.0 g) as an off-white solid, NMR (DMSO-d6) 3.15(s,3H) 3.85(s,3H) 7.2(d,1H) 7.3(s,1H) 7.85(d,1H) 10.5(s,1H).

1. temperatureheated
2. temperatureat reflux for 22 hours
3. temperatureIt was cooled
4. customevaporated to dryness
5. additiondiluted with water
6. extractionextracted with ethyl acetate
7. washwashed with aqueous sodium bicarbonate solution, water
8. dry with materialdried (MgSO4)
9. filtrationfiltered
10. customThe filtrate was evaporated to dryness