反应详情

A solution of 7-(dimethyl-t-butylsilyl)oxymethyl-4-p-methoxybenzyl-3-oxo-3,4-dihydro-2H-1,4-benzoxazine in tetrahydrofuran is treated with a solution of tetrabutylammonium fluoride in tetrahydrofuran and the reaction mixture left standing overnight. The solvent is evaporated, the residue is treated with aqueous hydrochloric acid and extracted with dichloromethane. The organic phase is washed with a solution of sodium bicarbonate, brine and then dried on sodium sulfate. Evaporation of the solvent and filtration through a small pad of silica gel yields the pure 7-hydroxymethyl-4-p-methoxybenzyl-3-oxo-3,4-dihydro-2H-1,4-benzoxazine. To a solution of 7-hydroxymethyl-4-p-methoxybenzyl-3-oxo-3,4-dihydro-2H-1,4-benzoxazine in dichloromethane is added triphenylphosphine and carbonium tetrabromide. Then a solution of diethyl azodicarboxylate in dichloromethane is added dropwise and the reaction mixture stirred at room temperature for 6 hours. The solvent is evaporated and the product isolated by flash chromatography.

1. waitthe reaction mixture left
2. customThe solvent is evaporated
3. additionthe residue is treated with aqueous hydrochloric acid
4. extractionextracted with dichloromethane
5. washThe organic phase is washed with a solution of sodium bicarbonate, brine
6. customdried on sodium sulfate
7. customEvaporation of the solvent and filtration through a small pad of silica gel