反应 #170990

反应方程式

2-(4-Aminophenoxy)-propionic acid 2-[2-(4-aminophenoxy)-acetoxy]-ethyl ester

dioxane

triphosgene

dioxane

→

40

收率 37.2%

2-(4-Isocyanatophenoxy)-propionic acid 2-[2-(4-isocyanatophenoxy)-acetoxy]-ethyl ester

收率 37.2%

反应条件

后处理

1. 1
   温度cooled to below 20° C
2. 2
   workup.DISTILLATIONA condenser was then arranged for distillation and solvent
3. 3
   其他removed by distillation at atmospheric pressure until the volume of the reaction mixture
4. 4
   workup.ADDITIONFresh dry dioxane (50 ml) was added
5. 5
   workup.DISTILLATIONthe solvent was distilled off under vacuum
6. 6
   其他The residue was re-evaporated two times from dry dioxane

实验过程

2-(4-Aminophenoxy)-propionic acid 2-[2-(4-aminophenoxy)-acetoxy]-ethyl ester 39 (5.2 g, 13.9 mmol) was dissolved in dry dioxane (80 ml) under nitrogen atmosphere and cooled to below 20° C. A solution of triphosgene (7 g, 23.6 mmol) in dry dioxane (20 ml) was added drop wise. The mixture was heated slowly to 75-80° C. and main-tained for 3 hrs. A condenser was then arranged for distillation and solvent removed by distillation at atmospheric pressure until the volume of the reaction mixture was reduced to approximately one third. Fresh dry dioxane (50 ml) was added and the solvent was distilled off under vacuum. The residue was re-evaporated two times from dry dioxane to give 40 (2.2 g, 37.2%) as a light yellow syrup.

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