反应详情

Benzene (20 ml.) was added to a solution of phosgene 2.5 g.) in benzene (11.4 ml.). A solution of diethyl 2-hydroxyiminomalonate (4.73 g.) and N,N-dimethylaniline (3.03 g.) in benzene (30 ml.) was added dropwise to the solution over 40 minutes at 5° C in a nitrogen stream. The mixture was stirred for 1 hour at the same temperature and overnight at room temperature. A solution of 4-methoxybenzylalcohol (3.11 g.) and pyridine (4.04 ml.) in benzene (30 ml.) was added dropwise to the resultant mixture containing diethyl 2-chlorocarbonyloxyiminomalonate over a period of 40 minutes at 5° C. The mixture was stirred for 2 hours at the same temperature, for 3 hours at room temperature and allowed to stand overnight. Cold water (100 ml.) was added to the reaction mixture to dissolve an insoluble material and cooled 1N-hydrochloric acid (20 ml.) was added thereto, after which the mixture was shaken. The organic layer was then washed 3 times with 1N hydrochloric acid (20 ml.), 3 times with a 5% sodium carbonate aqueous solution (20 ml.) and a sodium chloride aqueous solution, and then dried over magnesium sulfate. After drying, the solvent was distilled off to give diethyl 2-(4-methoxybenzyloxycarbonyloxyimino)malonate (6.89 g.), a pale brown oil, which was solidified on standing at ambient temperature.

1. stirringThe mixture was stirred for 2 hours at the same temperature, for 3 hours at room temperature
2. waitto stand overnight
3. dissolutionto dissolve an insoluble material
4. additionwas added
5. stirringafter which the mixture was shaken
6. washThe organic layer was then washed 3 times with 1N hydrochloric acid (20 ml.), 3 times with a 5% sodium carbonate aqueous solution (20 ml.)
7. dry with materiala sodium chloride aqueous solution, and then dried over magnesium sulfate
8. customAfter drying
9. distillationthe solvent was distilled off