反应详情

In 2 ml of toluene were dissolved 0.5 g of 6-cyano3,4-dihydro-2,2-dimethyl-2H-1,4-benzoxazine, 1.2 ml of 2,3-butanedione and a catalytic amount of p-toluenesulfonic acid and the mixture was stirred at 100° C. for 2 days. The solvent was then distilled off under reduced pressure and the residue was re-dissolved in toluene, washed with saturated aqueous sodium hydrogen carbonate solution and saturated aqueous sodium chloride solution, and dried over anhydrous magnesium sulfate. The solvent was then distilled off and the residue was purified by silica gel column chromatography to give 0.15 g of 6-cyano-3,4-dihydro-2,2-dimethyl-4-(2,5-dimethyl-3-furyl)-2H-1,4-benzoxazine.

1. distillationThe solvent was then distilled off under reduced pressure
2. dissolutionthe residue was re-dissolved in toluene
3. washwashed with saturated aqueous sodium hydrogen carbonate solution and saturated aqueous sodium chloride solution
4. dry with materialdried over anhydrous magnesium sulfate
5. distillationThe solvent was then distilled off
6. customthe residue was purified by silica gel column chromatography