Polycyclic aminopyridine compounds which are acetylcholinesterase inhibitors, process for preparing them and their use

A process for obtaining polycyclic aminopyridine compounds of general Formula I ##STR31## and their pharmaceutically acceptable salts, in which:

• R is hydrogen, alkyl, aralkyl, or acyl;
• R.sub.1 and R.sub.2 are, independently, hydrogen, alkyl, aralkyl, alkoxy, alkoxycarbonyl, amino or amino substituted with one or two alkyl, aralkyl or acyl groups;
• m and n are independently 1, 2 or 3;
• X is a bond between two carbons, an oxygen or sulphur atom, a group N--R.sub.3 --in which the group R.sub.3 has one of the meanings defined about for R--or an alkylene or alkenylene bridge containing from 1 to 5 carbon atoms and which may contain one or more substituents R.sub.4 --which are, respectively, hydrogen, lower alkyl, alkenyl or alkylidene having one to four carbon atoms with a linear or branched chain, phenyl, phenyl substituted with one or more lower alkyl groups having one to four carbon atoms, lower alkoxy groups having one to four carbon atoms or halogen groups, aralkyl, lower alkoxy containing from one to four carbon atoms, and hydroxyl--and when X is an alkenylene group, the latter may be fused to a saturated or unsaturated carbocyclic ring system, it being possible for the ring to be substituted with one or more groups R.sub.5 --which are lower alkyl or lower alkoxy having one to four carbon atoms, or halogen;
• Y is an alkenylene bridge containing from 3 to 5 carbon atoms and which may contain one or more substituents R.sub.4 as defined above;
• and ##STR32## p being an integer which is 3 or 4, q being an integer from 1 to 3 inclusive, and r being integer from an 1 to 4 inclusive, and R.sub.6 and R.sub.7 being substituents which are individually hydrogen, halogen, lower alkoxy or lower alkyl, the said process wherein ketones of general Formula (11) ##STR33## are reacted with the aminonitriles of general formula (III) ##STR34## in which general formulae (II) and (III) A, R.sub.1 and R.sub.2, X, Y, m and n have the meanings defined above, and, if necessary, when it is desired to obtain compounds in which R is other than hydrogen, the compounds of general structure (I) in which R is hydrogen are subjected to alkylation, aralkylation or acylation;
• or, when it is desired to obtain compounds in which R.sub.4 is an endo hydroxyl group, the corresponding keto precursor in which R.sub.4 is an oxo group is subjected to reduction;
• thereafter, if so desired, to form a pharmaceutically acceptable acid addition salt, a basic compound obtained is reacted with a suitable acid.