Reacción #61653

Ecuación de reacción

phosgene

1-(3-amino-5-benzyloxy-2-hydroxy-phenyl)-ethanone

hydrochloric acid

→

7-acetyl-5-benzyloxy-3H-benzoxazol-2-one

Disolventes

pyridine

Condiciones de reacción

Tratamiento posterior

1. 1
   OtroAt 20 to 40° C
2. 2
   workup.ADDITIONpoured onto ice
3. 3
   OtroA reddish-brown solid is isolated which
4. 4
   Otrois repeatedly recrystallised from ethanol with the addition of activated charcoal

Procedimiento

At 20 to 40° C. 52 g (0.53 mol) phosgene are piped into a solution of 121 g (0.47 mol) 1-(3-amino-5-benzyloxy-2-hydroxy-phenyl)-ethanone in 800 mL pyridine. The reaction mixture is heated to 50° C. for 2 hours, then poured onto ice and acidified with conc. hydrochloric acid. A reddish-brown solid is isolated which is repeatedly recrystallised from ethanol with the addition of activated charcoal.

Fuente