反应详情

2-(Benzooxazol-2-ylamino)-ethanol [compound of Step II] (9.76 g, 55 mmol) was taken in dry pyridine (40 mL) and to this solution, methanesulfonyl chloride (4.6 mL, 60 mmol) was added under stirring at room temperature. The reaction mixture was stirred for 15 hours, then diluted with ice water and extracted with dichloromethane (3×200 mL). The dichloromethane layer was washed with water and brine, dried over anhydrous sodium sulfate and was concentrated to give a crude material (18 g). The crude material obtained was purified using a silica gel column and 80% ethyl acetate in petroleum ether to yield sulfurous acid 2-(benzooxazol-2-ylamino)-ethyl ester methyl ester.

1. additionwas added
2. stirringThe reaction mixture was stirred for 15 hours
3. extractionextracted with dichloromethane (3×200 mL)
4. washThe dichloromethane layer was washed with water and brine
5. dry with materialdried over anhydrous sodium sulfate
6. concentrationwas concentrated
7. customto give a crude material (18 g)
8. customThe crude material obtained
9. customwas purified