反应详情

温度

-40 °C

The mixture of 6.9 g of methyl 3-oxo-3,4-dihydro-2H-benzo[1,4]oxazine-6-carboxylate and 230 ml of tetrahydrofuran is cooled to −40° C. Over 30 minutes, 88.9 ml of diisobutylaluminium hydride (1.5M in toluene) are added dropwise at −40° C. The reaction mixture is stirred at from −40° C. to −20° C. over 1.5 hours and subsequently poured cautiously onto 150 ml of 2N HCl (cold). The organic phase is removed and the water phase extracted with tetrahydrofuran (5×100 ml). The organic phases are washed with brine (1×100 ml), filtered through cottonwool and concentrated by evaporation. The title compound is obtained as beige crystals from the residue by crystallization (from ethanol). Rf (2:1 EtOAc-heptane)=0.16; Rt=2.23; m.p.: 186-187° C.

1. customThe organic phase is removed
2. extractionthe water phase extracted with tetrahydrofuran (5×100 ml)
3. washThe organic phases are washed with brine (1×100 ml)
4. filtrationfiltered through cottonwool
5. concentrationconcentrated by evaporation