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

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

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.

Herkunft & Nachweise