Abstract: Morpholine derivatives of the formula ##STR1## and their pharmaceutically acceptable acid addition salts possess analgesic and/or opiate antagonistic activity. In the formula R.sup.1 represents lower alkyl; R.sup.2 represents hydrogen, lower alkyl or (lower)alkoxymethyl; R.sup.3 represents hydrogen, lower alkyl, lower alkenyl, lower alkynyl, aryl(lower)alkyl, 2-tetrahydrofurylmethyl or cycloalkylmethyl and R.sup.4 represents a lower alkenyl or lower alkynyl group containing at least 3 carbon atoms and in which there is no unsaturated bond in the 1-position.

Abstract: Novel N-(4-pyridyl)acetamide derivatives having the formula ##STR1## [where R.sup.1 and R.sup.2 are aryl or heteroarly (optionally linked together by a lower alkylene bridge) or one of R.sup.1 and R.sup.2 is aryl or heteroaryl and the other of R.sup.1 and R.sup.2 is lower alkyl or ar(lower)alkyl, R.sup.3 and R.sup.4 are each hydrogen or lower alkyl] and their nontoxic acid addition salts are described. They are chemical intermediates for the preparation of 4-pyridinamine derivatives having the formula ##STR2## which show CNS activity and may be used as antidepressant drugs.

Abstract: Morpholine derivatives of the formula ##STR1## and their pharmaceutically acceptable acid addition salts[wherein R.sup.1 represents lower alkyl. R.sup.2 represents hydrogen, lower alkyl, benzyl, lower alkoxymethyl or an acyl group; R.sup.3 represents hydrogen, lower alkyl or phenyl; R.sup.4, R.sup.5 and R.sup.6 are independently hydrogen or lower alkyl and R.sup.7 is hydrogen, lower alkyl, lower alkenyl, lower alkynyl, aryl(lower)alkyl, tetrahydrofurylmethyl or cycloalkylmethyl] possess analgesic and/or opiate antagonistic activity.

Abstract: New 4-pyridinamine derivatives having the formula ##STR1## and their pharmaceutically acceptable acid addition salts, [wherein one of R.sup.1 and R.sup.2 is aryl or heteroaryl, the other of R.sup.1 and R.sup.2 is lower alkyl, R.sup.3 and R.sup.4 are independently hydrogen or lower alkyl, and n is 0 or 1] are described. They show CNS activity and may used as antidepressant drugs. N-([.alpha.-Phenyl]-n-propyl)-4-pyridinamine also shows anti-ulcer activity.

Abstract: Pyridine derivatives having the formula ##STR1## and their N-oxides and pharmaceutically acceptable acid addition salts, wherein R.sup.1 and R.sup.2 are independently aryl, R.sup.3 is hydrogen or lower alkyl and n is 0, 1 or 2, have CNS activity and may be used as antidepressants.

Abstract: Novel 4-pyridinamine derivatives having the formula ##STR1## and their pharmaceutically acceptable acid addition salts (wherein A is C.sub.1 to C.sub.4 alkylene, each of B.sub.1 and B.sub.2, together with the two carbon atoms joined thereto, forms arylene or heteroarylene, R.sub.3 and R.sub.4 are independently hydrogen or lower alkyl and n is 0 or 1) are described. They show CNS activity and may be used as anti-depressant drugs.

Abstract: Novel 4-pyridinamine derivatives having the formula ##STR1## [where R.sup.1 and R.sup.2 are aryl or heteroaryl (optionally linked together by a lower alkylene bridge) or one of R.sup.1 and R.sup.2 is aryl or heteroaryl and the other of R.sup.1 and R.sup.2 is lower alkyl or ar(lower)alkyl, R.sup.3 and R.sup.4 are each hydrogen or lower alkyl and n is 0 or 1] and their non-toxic acid addition salts are described. They show CNS activity and may be used as antidepressant drugs. Some also show stimulant activity.Novel intermediates having the formula ##STR2## are also described.