Abstract: Compounds of general formula (I): ##STR1## in which: R.sub.1 and R.sub.2 each represent a hydrogen atom or, with the oxygen and nitrogen, form an --O--CO--N-- linkage,W represents a halogen atom or a lower alkyl or alkoxy group optionally substituted with one or more halogen atoms, such as trifluoromethyl, and m being between 0 and 3,A represents a linear or branched lower alkylene group, andAr represents an aryl or heteroaryl group optionally substituted with one or more halogen atoms or with one or more lower alkyl, hydroxy, hydroxysulfonyloxy, lower alkoxy or aryloxy groups optionally substituted with one or more halogen atoms, such as a trifluoromethyl group,on the understanding that lower alkyl or lower alkyloxy radical is understood to mean a linear or branched alkyl group comprising from 1 to 6 carbon atom, their isomers, epimers and diastereoisomers. Medicinal products useful in the treatment of pain.

Abstract: Process for the synthesis of compounds of formula (I): ##STR1## their pyridinium salts and N-oxides, in which formula: the nitrogen of the pyridine ring is situated in the .alpha.-, .beta.-, .gamma.- or .delta.-position with respect to the ring junction;R.sup.1 represents a halogen, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkoxy or a nitro, substituted or unsubstituted amino, phenyl or cyano group;0.ltoreq.m.ltoreq.2;R.sup.2 represents a lower alkyl or cycloalkyl group, a 5- or 6-membered heterocycle containing 1 or 2 hetero atoms, substituted or otherwise, or an aryl group ##STR2## such that: R.sup.3 represents a halogen, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkoxy or a nitro, phenyl, substituted or unsubstituted sulfonyl, cyano, thioalkyl, substituted or unsubstituted amino, substituted or unsubstituted sulfinyl, mercapto, hydroxyl or ester group,0.ltoreq.n.ltoreq.