反应详情

温度

50 °C

A solution of 32.8 g of sodium hydroxide, dissolved in 330 ml of methanol, was slowly added dropwise to a mixture of 170.0 g (0.54 mol) of methyl 2-chloro-3-(4,5-dihydroisoxazol-3-yl)-4-methylsulfonylbenzoate and 1 l of methanol at 40-45° C. The suspension was stirred for 5 hours at 50° C. After the solvent had been distilled off, the residue was taken up in 1.5 l of water, and the aqueous phase was extracted three times with ethyl acetate. The aqueous phase was acidified with hydrochloric acid and extracted three times with ethyl acetate. The combined organic phases were subsequently washed to neutrality with water, dried and concentrated. This gave 148.8 g (91% of theory) of 2-chloro-3-(4,5-dihydroisoxazol-3-yl)-4-methylsulfonylbenzoic acid.

1. distillationAfter the solvent had been distilled off
2. extractionthe aqueous phase was extracted three times with ethyl acetate
3. extractionextracted three times with ethyl acetate
4. washThe combined organic phases were subsequently washed
5. customdried
6. concentrationconcentrated