Triethylamine → (4-Isocyanato-phenoxy)-acetic acid methyl ester

Temperatur

75 °C

To a mixture of (4-aminophenoxy)-acetic acid methyl ester 3 (15 g, 82.87 mmol) and triethylamine (16.77 g, 165.73 mmol) in toluene (225 ml) under nitrogen atmosphere at 0° C. was added triphosgene (9 g, 30.33 mmol) in one lot. The reaction was exo-thermic and the temperature rose to 25° C. Later the reaction mixture was heated to 75° C. over a period of one hour and maintained at this temperature for 26 hours. The reaction mixture was cooled to room temperature, the solids were filtered off, and toluene was distilled off under vacuum to get crude 4, which was vacuum distilled to get pure 4 (10 grams, 58.3%) as a white powder with an m.p between 50-53° C.

1. customrose to 25° C
2. temperaturemaintained at this temperature for 26 hours
3. temperatureThe reaction mixture was cooled to room temperature
4. filtrationthe solids were filtered off
5. distillationtoluene was distilled off under vacuum
6. customto get crude 4, which
7. distillationdistilled

ORD-Eintrag

ord-3b5f043239244cea8c03e1d5a5f191d8

Quelldatensatz

uspto-grants-2014_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08846845B2