反应详情

3.4 ml of sulfuric acid (63.59 mmol; 1.16 V) and 3.4 ml of water were added to a solution of 2.93 g of 2-tert-butyl-6-chlorobenzooxazole-7-sulfonic acid dimethylamide (9.25 mmol; 1.0 eq) in 13 ml of 1,4-dioxane. The reaction medium was refluxed for four and a half hours. The reaction medium was concentrated. 130 ml of 1 M sodium hydroxide were added to the residue (pH=10), followed by 400 ml of water. The solution was extracted with ethyl acetate (2×250 ml). The organic phases were combined, dried over anhydrous sodium sulfate, filtered and concentrated. The residue was chromatographed on silica gel (250 g prepacked column: eluent heptane/ethyl acetate, from 20% to 40% of ethyl acetate, flow rate 100 ml/min). 1.66 g of 3-amino-6-chloro-2-hydroxy-N,N-dimethylbenzenesulfonamide were obtained. Yield=72%.

1. temperatureThe reaction medium was refluxed for four and a half hours
2. concentrationThe reaction medium was concentrated
3. addition130 ml of 1 M sodium hydroxide were added to the residue (pH=10)
4. extractionThe solution was extracted with ethyl acetate (2×250 ml)
5. dry with materialdried over anhydrous sodium sulfate
6. filtrationfiltered
7. concentrationconcentrated
8. customThe residue was chromatographed on silica gel (250 g prepacked column: eluent heptane/ethyl acetate, from 20% to 40% of ethyl acetate, flow rate 100 ml/min)