Abstract: A compound of formula (VIII): ##STR1## in which Alk is a (C.sub.1 -C.sub.4)alkyl group, R.cndot. is hydrogen or a protecting group cleavable by hydrolysis and R is hydrogen, a protecting group cleavable by reduction or a heterocycle of structure (IX): ##STR2## in which Hal is a halogen atom and X, Y and Z are each --CH.dbd. or one of them is a nitrogen atom and the others are --CH.dbd., and its salts, R.cndot. being other than hydrogen if R is hydrogen or a group of structure (IX).

Abstract: The present invention relates to novel heteroarylpiperidines of formula (I): ##STR1## in which Hal is a halogen atom, Alk is a C.sub.1-4 alkyl group and one of X, Y and Z is a nitrogen atom while the others are .dbd.CH--, and their salts. These compounds are useful as 5-HT.sub.3 agonists.

Abstract: The present invention relates to new 1-heteroarylazetidines and new 1-heteroarylpyrrolidines endowed with 5-HT.sub.3 agonist activity of formula (I): ##STR1## in which A is --CH.dbd.N-- or --N.dbd.CH--; R is hydrogen, halogen, C.sub.1-4 alkyl, C.sub.1-4 alkoxy, C.sub.1-4 alkylthio, cyano, carboxamido, trifluoromethyl, a vinyl group, a formyl group, a carboxyl group in free, salt or esterified form, hydroxyl, hydroxymethyl, mercapto, amine, mono- or di-(C.sub.1-4 alkyl)amino, aminomethyl, mono- or di(C.sub.1-4 alkyl)aminomethyl, 1-piperido, 1-pyrrolidino, 1-piperazino or 4-(C.sub.1-4 alkyl)-1-piperazino, where R may replace any one of the hydrogen atoms of the heteroaryl nucleus;R.sub.1 is hydrogen or a methyl group;R.sub.2 and R.sub.3, which are identical or different, are hydrogen or C.sub.1-4 alkyl;n is 1 or 2; m is 0 or 1; and m+n.gtoreq.2;and addition salts with inorganic or organic acids of the compounds of formula (I).

Abstract: The present invention relates to new 1-heteroarylazetidines and new 1-heteroarylpyrrolidines endowed with 5-HT.sub.3 agonist activity of formula (I): ##STR1## in which A is --CH=CH--; R is hydrogen, halogen, C.sub.1-4 alkyl, C.sub.1-4 alkoxy, C.sub.1-4 alkylthio, cyano, carboxamido, trifluoromethyl, a vinyl group, a formyl group, a carboxyl group in free, salt or esterified form, hydroxyl, hydroxymethyl, mercapto, amino, mono- or di-(C.sub.1-4 alkyl)amino, aminomethyl, mono- or di(C.sub.1-4 alkyl)aminomethyl, 1-piperido, 1-pyrrolidino, 1-piperazino or 4-(C.sub.1-4 alkyl)-1-piperazino, where R may replace any one of the hydrogen atoms of the heteroaryl nucleus;R.sub.1 is hydrogen or a methyl group;R.sub.2 and R.sub.3, which are identical or different, are hydrogen or C.sub.1-4 alkyl;n is 1 or 2; m is 0 or 1; and m+n.gtoreq.2;and addition salts with inorganic or organic acids of the compounds of formula (I).

Abstract: The present invention relates to novel heteroarylpiperidines of formula (I): ##STR1## in which Hal is a halogen atom, Alk is a C.sub.1 -C.sub.4 alkyl group and X, Y and Z are each --CH.dbd. and their salts, to a process for their preparation and to their use as drugs active as 5-HT.sub.3 agonists.

Abstract: New therapeutic use of some heterocyclylpiperazines of formula (I) ##STR1## wherein R represents hydrogen or (C.sub.1 -C.sub.4)alkyl, R.sub.1 represents hydrogen or a methyl group, R.sub.2 represents hydrogen or a halogen atom; X et Y represent each --CH.dbd., or one is --CH.dbd. and the other is --N.dbd., as well as their pharmaceutically acceptable salts for the preparation of a medicament for the treatment or prophylaxis of the pathological conditions which can be improved by 5-HT.sub.3 mediated selective agonism and new compounds deriving from this chemical class.

Abstract: The present invention relates to new 1-heteroarylazetidines and new 1-heteroarylpyrrolidines endowed with 5-HT.sub.3 agonist activity of formula (IV): ##STR1## The substituents A, R', R.sub.1 and P, and the variables n and m, are as herein described.