反应详情

A solution of the product of Step 1 (0.1 mol) in dichloromethane (300 ml) was cooled to 0° C. and treated with N,O-dimethylhydroxylamine hydrochloride (11.7 g, 0.12 mol) followed by triethylamine (36 ml, 0.36 mol). The mixture was allowed to warm to room temperature and stirred for 30 minutes The solvent was evaporated in vacuo and the residue partitioned between ethyl acetate and water. After separation of the layers, the organic phase was washed sequentially with 2M hydrochloric acid, water and brine, dried and concentrated in vacuo. The product was purified by silica gel chromatography eluting with ethyl acetate/hexane (1:1) to give the title compound (30.1 g, 96%); 1H NMR (CDCl3) 7.12 (1H, s), 3.78 (3H, s), 3.31 (3H, s).

1. customwas evaporated in vacuo
2. customthe residue partitioned between ethyl acetate and water
3. customAfter separation of the layers
4. washthe organic phase was washed sequentially with 2M hydrochloric acid, water and brine
5. customdried
6. concentrationconcentrated in vacuo
7. customThe product was purified by silica gel chromatography
8. washeluting with ethyl acetate/hexane (1:1)