反应详情

Hydroxylamine hydrochloride (0.89 g, 12.8 mmol) was added to a suspension of 4-(2,4-bis(benzyloxy)-5-chlorophenyl)-2-hydroxy-4-oxobut-2-enoate (5.0 g, 10.7 mmol) in EtOH (100 ml). The reaction mixture was heated to reflux for 3.5 h and then allowed to cool to RT. The resulting suspension was filtered, washed sequentially with EtOH (2×10 ml), water (2×10 ml), and EtOH (2×10 ml), and dried under vacuo to afford the title compound ethyl 5-(2,4-bis(benzyloxy)-5-chlorophenyl)isoxazole-3-carboxylate (3.97 g, 80%) as a flocculent light-yellow solid.

1. temperatureThe reaction mixture was heated
2. temperatureto reflux for 3.5 h
3. filtrationThe resulting suspension was filtered
4. washwashed sequentially with EtOH (2×10 ml), water (2×10 ml), and EtOH (2×10 ml)
5. customdried under vacuo