反应详情

To a solution of hydroxylamine hydrochloride (20.85 g) in DMSO (200 ml) was added triethylamine (3.9 g) and the mixture was stirred for 30 minutes at room temperatures. To the reaction mixture was added the compound (16 g) obtained in Example (34c), and the mixture was stirred for 60 hours at 70° C. To the resultant mixture was added tetrahydrofuran (100 ml). After removal of crystalline precipitate by filtration, the filtrate was concentrated to dryness. The residue was partitioned between water (1.2 liter) and ethyl acetate (350 ml), and the upper layer was washed with water (70 ml×3). Ethyl acetate was evaporated under reduced pressure, and to the residue was added methanol (70 ml). Resulting crystalline precipitate was filtered off. The filtrate was concentrated to dryness under reduced pressure to give the title compound as a pale yellow syrup (13.0 g, 76%).

1. stirringthe mixture was stirred for 60 hours at 70° C
2. customAfter removal of crystalline precipitate
3. filtrationby filtration
4. concentrationthe filtrate was concentrated to dryness
5. customThe residue was partitioned between water (1.2 liter) and ethyl acetate (350 ml)
6. washthe upper layer was washed with water (70 ml×3)
7. customEthyl acetate was evaporated under reduced pressure
8. additionto the residue was added methanol (70 ml)
9. filtrationResulting crystalline precipitate was filtered off
10. concentrationThe filtrate was concentrated to dryness under reduced pressure