The ethanolamides of 3-dimethylaminopropionic acid, 1-methyl-1,2,5,6-tetrahydronicotinic acid (arecaidine) and 1-methylhexahydronicotinic acid, and propanolamides of 3-dimethylaminopropionic acid and arecaidine have been synthesised. None of these compounds had demonstrable oxytocic activity on the isolated oestrous rat uterus in concentrations up to 1 mg./ml. Arecaidine propanolamide inhibited acetylcholine-induced contractions in concentrations of 0.075 to 0.3 mg./ml. The 2-styryl derivatives of 3-dimethylaminopropionic and 4-dimethylaminobutyric acids were found to be unstable.