反应 #3422974
相关文献 (1)
openreactiondata ↗doi:10.6084/m9.figshare.5104873.v1; patent:US05317100
反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.
实验步骤: A solution of 11.6 g of oxalyl chloride in 25 ml of methylene chloride is added dropwise, in the course of 15 minutes, to a mixture, cooled to -25°, of 20 g of dimethylforinaniide and 115 ml of methylene chloride. The white suspension is stirred for a further 20 minutes at -25°, and a solution of 28.5 g of the dicyclohexylammonium salt of (2R,3R,)-2,3-epoxybutyric acid in 115 ml of methylene chloride is then added in the course of 10 minutes. The reaction mixture is stirred for a further 20 minutes at the same temperature, and a solution of 17.87 g of di-tert-butyl iminodiacetate in 90 ml of methylene chloride and 9.22 ml of N-methylmorpholine are then added dropwise simultaneously in the course of 15 minutes. The cooling bath is removed and the reaction mixture is stirred for 3 hours at room temperature. The white suspension is then filtered through a sintered glass suction filer, the residue is washed with methylene chloride, and the filtrate is diluted with methylene chloride and washed successively with water, 5% aqueous citric acid, saturated aqueous sodium bicarbonate solution and water. The aqueous phases are subsequently extracted twice with methylene chloride, and the combined organic phases are dried and evaporated under a water pump vacuum. The yellow-brown crude product is purified by flash chromatography over silica gel (Merck 9385) using a 9:1 mixture of methylene chloride and ethyl acetate as the mobile phase. (2R,3R)-N,N-Bis-(tert-butoxy-carbonylmethyl)-2,3-epoxybutyramide is obtained in the form of a pale yellow oil, [α]D =+52° (c=1.250% in chloroform). The reaction mixture is stirred for a further 20 minutes at the same temperature The cooling bath is removed the reaction mixture is stirred for 3 hours at room temperature The white suspension is then filtered through a sintered glass suction filer the residue is washed with methylene chloride the filtrate is diluted with methylene chloride washed successively with water, 5% aqueous citric acid, saturated aqueous sodium bicarbonate solution and water The aqueous phases are subsequently extracted twice with methylene chloride the combined organic phases are dried evaporated under a water pump vacuum The yellow-brown crude product is purified by flash chromatography over silica gel (Merck 9385) a 9:1 mixture of methylene chloride and ethyl acetate as the mobile phase
来源 ID: ord-76d50f2d7a4c4fd6b0b7a98b54643f2b