反应详情

温度

220 °C

A mixture of 66 g of 3-cyclohexyl-7-methoxy-3,4-dihydro-benzo[e][1,3]oxazin-2-one and 200 g of pyridinium HCl are heated without solvent on a metal bath to 220° C. for 45 minutes whilst stirring. Evolving HCl gas is sucked off. The mixture obtained is cooled to RT, the melt obtained is dissolved in H2O and EtOAc and two phases obtained are separated. The aqueous layer obtained is extracted with EtOAc and washed with 1N HCl, dried and concentrated in vacuo. The concentration residue obtained is filtered over silica gel and the filtration residue obtained is concentrated. 3-Cyclohexyl-7-hydroxy-3,4-dihydro-benzo[e][1,3]oxazin-2-one is obtained in crystallized form. m.p. 193-196°.

1. customThe mixture obtained
2. temperatureis cooled to RT
3. customthe melt obtained
4. customare separated
5. customThe aqueous layer obtained
6. extractionis extracted with EtOAc
7. washwashed with 1N HCl
8. customdried
9. concentrationconcentrated in vacuo
10. customThe concentration residue obtained
11. filtrationis filtered over silica gel
12. customthe filtration residue obtained
13. concentrationis concentrated