Реакция #589022

Уравнение реакции

6-(4-aminophenoxy)-hexanoic acid methyl ester

triethylamine

triphosgene

→

18

Выход 72.3%

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

Выход 72.3%

Растворители

toluene

Условия реакции

Обработка

1. 1
   Другоеrose to 60° C
2. 2
   Температураmaintained at this temperature for 26 hours
3. 3
   ТемператураThe reaction mixture was cooled to room temperature
4. 4
   Фильтрацияthe solids filtered off
5. 5
   workup.DISTILLATIONtoluene distilled off under vacuum
6. 6
   Другоеto get crude 18, which
7. 7
   workup.DISTILLATIONdistilled

Методика

To 6-(4-aminophenoxy)-hexanoic acid methyl ester 17 (26 g, 109.7 mmol) and triethylamine (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.

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