Patent ID: 6288264
Filing Date: 2001-09-11
Classification: C07C

Abstract:
A process for preparing cyanoacetamide from cyanoacetic acid and ammonia, comprising:(1) optionally, azeotropically distilling out water from cyanoacetic acid with a first monohydric alcohol having 4 to 10 carbon atoms;(2) esterifying said cyanoacetic acid with a second monohydric alcohol without additional catalyst;distilling out the water/alcohol mixture, thereby providing a crude ester;(3) optionally purifying said crude ester by distillation out from high boilers, thereby providing a purified ester;(4) reacting said crude ester or said purified ester with ammonia in the presence of a basic catalyst, thereby providing crude cyanoacetamide; and(5) working up the crude cyanaoacetamide by a mechanical separating operation and thermal treatment.