| 摘要 |
Basic esters of monoalkyl-isobutyl-acetic acids are prepared by reacting said acids or their reactive functional derivatives, i.e. their halides, esters or anhydrides, with amino alcohols, viz. amino-alkanols or cycloalkanols substituted in the amino group by two alkyl groups which may form part of a ring, if necessary in the presence of a condensation agent, by reacting the acids or their salts with reactive esters of the said amino alcohols such as their esters with hydrogen halides or arylsulphonic acids; or by converting the said acids into their halogen alkyl esters and reacting these with secondary amines. The halogen alkyl esters may be prepared by reacting the said acids or their halides, esters or anhydrides with alkylene halohydrin or salts of the acids with alkylene halohydrin or alkylene dihalide, and replacing any hydroxyl groups by halogen. The basic esters have cramp-relieving properties and their salts are water soluble. In examples: (1) n-propyl-isobutyl-acetic acid chloride is heated with b -diethylaminoethanol and the basic ester isolated. Dimethylaminoethanol, dimethyl- (or ethyl) aminopropanol, piperidinoethanol and m-dimethylaminocyclohexanol may be used similarly; (2) di-isobutyl-acetic acid is heated with b -chlorethyl-diethylamine and potash in acetic ester and the ester recovered. n-Butyl-(or amyl) isobutyl-acetic acid may be converted similarly; (3) di-isobutyl-acetic acid chloride is converted with ethylene chlorhydrin in presence of pyridine and the recovered b -chlorethyl ester reacted with piperidine. |
