反应详情

To a mixture of 4-hydroxybenzaldehyde (6.1 g, 50 mmol) in dry DMF (40 mL), was added sodium hydride (2.2 g, 55 mmol, 60% suspension) under stirring, in a nitrogen atmosphere at room temperature. The thick solution was diluted with dry DMF (20 mL). Sulfurous acid 2-(benzooxazol-2-ylamino)-ethyl ester methyl ester [compound of Step III] (14 g, 55 mmol) dissolved in dry DMF was added dropwise to the reaction mixture over a period of 20 min and the resulting mixture was heated to 80° C. for 1 hour. The reaction mixture was poured on crushed ice and then extracted with ethyl acetate (3×200 mL). The ethyl acetate layer was washed with water and brine, dried over anhydrous sodium sulfate, concentrated and purified using silica gel column and 50% ethyl acetate in petroleum ether to give 4-[2-(benzooxazol-2-ylamino)-ethoxy]-benzaldehyde.

1. additionwas added dropwise to the reaction mixture over a period of 20 min
2. temperaturethe resulting mixture was heated to 80° C. for 1 hour
3. additionThe reaction mixture was poured
4. customon crushed ice
5. extractionextracted with ethyl acetate (3×200 mL)
6. washThe ethyl acetate layer was washed with water and brine
7. dry with materialdried over anhydrous sodium sulfate
8. concentrationconcentrated
9. custompurified