Manufacturing Process
2-Chlorbutiric acid dimethyl amide are dissolved in absolute benzene and
heated to 110°C with propylamine in the autoclave. After cooling the
propylamine hydrochloride is filtered off, then the benzene solution is treated
with water and freed from any dissolved propylamine hydrochloride by means
of potassium lye. After distillation of the benzene the 2-propylaminobutyric
acid dimethyl amide is rectified in vacuum.
2-Propylaminobutyric acid dimethyl amide is dissolved in benzene and while
cooling, crotonic acid chloride is added and mixed. Then, reaction mixture is
filtered and freed from benzene to give 2-(N-propyl-crotonylamido)butyric acid
dimethyl amide, melting point 128°-130°C.
