Reaction #2045021

Reaction equation

2-(4-Aminophenoxy)propionic acid methyl ester

2-(4-Amino-phenoxy)-propionic acid methyl ester

triethylamine

triphosgene

→

32

Yield 143.8%

2-(4-Isocyanato-phenoxy)-propionic acid methyl ester

Yield 143.8%

Solvents

toluene

Conditions

Workup

1. 1
   Temperaturemaintained at this temp
2. 2
   TemperatureThe reaction mixture was cooled to room temperature
3. 3
   Filtrationthe solids were filtered off
4. 4
   workup.DISTILLATIONthe toluene was distilled off under vacuum
5. 5
   Otherto get crude 32, which
6. 6
   workup.DISTILLATIONdistilled

Procedure

To a mixture of 2-(4-Aminophenoxy)propionic acid methyl ester 18 (15 grams, 76.9 mmol) and triethylamine (15.6 g, 154.16 mmol) in toluene (210 ml) under nitrogen atm. was added triphosgene (8.4 g, 28.3 mmol) in one lot. Later the reaction mixture was heated to 75° C. over a period of one hour and maintained at this temp. for 26 hours. The reaction mixture was cooled to room temperature, the solids were filtered off, and the toluene was distilled off under vacuum to get crude 32, which was vacuum distilled to get pure 32 (9 g, 52.9%) as a light yellow syrup.

Source