反应详情

温度

-40 °C

A solution of 75.60 g of methyl 2,2-dimethyl-3-oxo-3,4-dihydro-2H-benzo[1,4]oxazine-6-carboxylate in 2700 ml of anhydrous tetrahydrofuran is cooled to −40° C. 858 ml of diisobutylaluminium hydride solution (1M in toluene) are added dropwise at −45-−40° C. The reaction mixture is subsequently stirred at −40° C. for a further 2 hours and finally warmed slowly to −20° C. The reaction mixture is poured onto 360 ml of 32% HCl. The phases are separated and the organic phase is washed with 1000 ml of 1M aqueous sodium potassium tartrate solution. The combined aqueous phases are re-extracted with 1000 ml of tetrahydrofuran and the combined organic phases are dried over sodium sulphate and concentrated by evaporation. The residue is taken up in 500 ml of tert-butyl methyl ether and the suspension is stirred at 45° C. over 1 hour. The title compound is obtained as a beige solid by filtration. Rt=2.69.

1. temperaturefinally warmed slowly to −20° C
2. customThe phases are separated
3. washthe organic phase is washed with 1000 ml of 1M aqueous sodium potassium tartrate solution
4. extractionThe combined aqueous phases are re-extracted with 1000 ml of tetrahydrofuran
5. dry with materialthe combined organic phases are dried over sodium sulphate
6. concentrationconcentrated by evaporation
7. stirringthe suspension is stirred at 45° C. over 1 hour