Abstract: A new piperidine derivative represented by the formula: ##STR1## wherein X is oxygen, sulfur, carbonyl, hydroxymethylene or methylene; R.sub.1 is straight-chain alkylene having 1-4 carbon atoms with or without lower alkyl substituent(s); (A).sub.m and R.sub.2 are usually used substituents; and Y is a monovalent group or a divalent group and is one of the following three groups: ##STR2## wherein when p is 0, B is --N.dbd.N--, ##STR3## and when p is 1, B is ##STR4## wherein (R.sub.3).sub.n is a usually used substituent, has hypotensive activity.

Abstract: New piperidine derivatives which have a useful pharmacological activity such as hypotensive activity are prepared.

Abstract: New piperidine derivatives which have a useful pharmacological activity such as hypotensive activity are prepared.

Abstract: Ethanolamine derivatives and their acid addition salts are prepared (1) by reacting a 1-(3,4-methylenedioxyphenyl)-2-aminoethanol compound or an .alpha.-amino-(3,4-methylenedioxy)acetophenone compound with an alkanal or an alkanone under reduction conditions, (2) by hydrogenating and/or hydrogenolyzing a 1-(3,4-methylenedioxyphenyl)-2-(N-substituted amino)-ethanol compound or an .alpha.-(N-substituted amino)-(3,4-methylenedioxy)acetophenone compound, and (3) by reacting a (3,4-methylenedioxyphenyl)-ethylene oxide compound or a 1-(3,4-methylenedioxyphenyl)-2-substituted ethanol compound with an amine. The ethanolamine derivatives and their salts show .beta.-adrenergic receptor blocking activity, and are expected to be useful in the treatment of heart disease, hypertension, myocardites and pheochromocytoma.