反应详情

1.93 ml (1.93 mmol) of 1N aqueous hydrochloric acid were added to a solution of 600 mg (1.75 mmol) of ethyl 4-(N-benzyloxycarbonyl-N-methylamino)phenoxyacetate (prepared as described in Preparation 16) in 18 ml of methanol, and the mixture was stirred at room temperature for 1.5 hours in the presence of a palladium-on-charcoal catalyst, under an atmosphere of hydrogen. At the end of this time, the catalyst was removed by filtration, and the filtrate was freed from the solvent by distillation under reduced pressure. The resulting residue was mixed with benzene, and the mixture was dehydrated by azeotropic distillation. This operation was repeated again, to give ethyl 4-methylaminophenoxyacetate as a residue. The whole of this residue was dried in vacuo and then dissolved in 2 ml of dimethylformamide. 186 mg (1.75 mmol) of sodium carbonate and 0.12 ml (1.93 mmol) of methyl iodide were added to the solution, and the mixture was stirred at room temperature for 48 hours. At the end of this time, the reaction mixture was concentrated by evaporation under reduced pressure, and the concentrate was mixed with ethyl acetate. The resulting organic mixture was washed with a 5% w/v aqueous solution of sodium hydrogencarbonate, with a 5% w/v aqueous solution of sodium thiosulfate and with a saturated aqueous solution of sodium chloride, in that order. The reaction mixture was then dried over anhydrous sodium sulfate, and the solvent was removed by distillation under reduced pressure. The resulting residue was purified by preparative thin layer chromatography, using a 1:1 by volume mixture of hexane and ethyl acetate as the developing solvent, to give 129 mg of the title compound as an oil.

1. customAt the end of this time, the catalyst was removed by filtration
2. distillationthe filtrate was freed from the solvent by distillation under reduced pressure
3. additionThe resulting residue was mixed with benzene
4. distillationthe mixture was dehydrated by azeotropic distillation