Manufacturing Process
2-Clorobutiric acid dimethyl amide is dissolved in absolute benzene and
heated to 110°-120°C with ethylamine in the autoclave. After cooling the
ethylamine hydrochloride is filtered off, then the benzene solution is treated
with water and freed from any dissolved ethylamine hydrochloride by means
of potassium lye. After distillation of the benzene the 2-ethylaminobutyric acid
dimethyl amide is rectified in vacuum.
2-Ethylaminobutyric acid dimethyl amide is dissolved in absolute ether, then
the mixture is well cooled and treated drowsy under stirring with crotonic acid
chloride. After a stirring reaction mixture is filtered and residue obtained is
dissolved in water and treated by potassium hydroxide. The remaining product
is finally rectified in high vacuum to give 2-(N-ethyl-crotonylamido)butyric
acid dimethyl amide.
