反应详情

The stirred solution of 3.70 g of 6-hydroxymethyl-4H-benzo[1,4]oxazin-3-one (Example 2d) and 95 ml of N,N-dimethylformamide is cooled to 0° C., admixed with 0.808 g of sodium hydride (60% dispersion) and stirred over 1 hour. After 7.57 g of (4-bromobutoxy)triisopropylsilane have been added, the mixture is stirred at 0° C. over a further 18 hours and the resulting reaction mixture is poured onto aqueous 1M sodium hydrogencarbonate solution (200 ml). The mixture is extracted with tert-butyl methyl ether (2×200 ml). The organic phases are washed successively with water (3×200 ml) and brine (200 ml), dried over sodium sulphate, filtered and concentrated by evaporation. The title compound is obtained as a slightly yellowish oil from the residue by means of flash chromatography (SiO2 60F). Rf=0.43 (1:1 EtOAc-heptane); Rt=5.86.

1. stirringthe mixture is stirred at 0° C. over a further 18 hours
2. customthe resulting reaction mixture
3. extractionThe mixture is extracted with tert-butyl methyl ether (2×200 ml)
4. washThe organic phases are washed successively with water (3×200 ml) and brine (200 ml)
5. dry with materialdried over sodium sulphate
6. filtrationfiltered
7. concentrationconcentrated by evaporation