反应详情

3 g (mmol) of methyl chloroformate were added dropwise at 0° C. to a mixture of 7.8 g (39 mmol) of N-(2-phenoxypyridin-3-yl)hydroxylamine (Example 1.b), 4 g (50 mmol) of NaHCO3 (solid) and 10 ml of methylene chloride. After 1 hour at room temperature (approximately 25° C.), the reaction mixture was treated with a further 2 g of methyl chloroformate and stirred for a further 2 hours at room temperature. The reaction mixture was subsequently treated with a further 2 g of methyl chloroformate and left for approximately 12 hours at 5° C. The resulting mixture was treated with water and extracted repeatedly using tert-butyl methyl ether. The organic phases were combined, washed and dried, and the solvent was removed under reduced pressure. The residue obtained was purified by column chromatography (cyclohexane/ethyl acetate). This gave 2.5 g of the title compound as a solid (m.p.: 140° C.

1. waitleft for approximately 12 hours at 5° C
2. extractionextracted repeatedly using tert-butyl methyl ether
3. washwashed
4. customdried
5. customthe solvent was removed under reduced pressure
6. customThe residue obtained
7. customwas purified by column chromatography (cyclohexane/ethyl acetate)