Triethylamine → 6-(4-Isocyanatophenoxy)-hexanoic acid methyl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To 6-(4-aminophenoxy)-hexanoic acid methyl ester 17 (26 g, 109.7 mmol) and tri-ethylamine (29.2 g, 288.56 mmol) in toluene (390 ml) under nitrogen atmosphere was added triphosgene (15.6 g, 52.56 mmol) in one lot. The reaction was exothermic and internal temperature rose to 60° 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 filtered off, and toluene distilled off under vacuum to get crude 18, which was vacuum distilled to get pure 18 (10 g, 34.7%) with an m.p between 47-50° C.

Herkunft & Nachweise