Pyridinium compounds which are useful as antagonists of platelet activating factor

A compound of the formula:

• ##STR18## wherein:
• (A) X is a divalent radical of:
• ##STR19## wherein Y is a divalent radical (CH.sub.2).sub.n, or p is the integer 1, 2, or 3;
• n is the integer 0, 1, or 2;
• R.sub.4 is hydrogen, phenyl, --COR.sub.6 or --SO.sub.2 R.sub.7 ;
• wherein R.sub.6 is C.sub.1 -C.sub.6 alkyl, C.sub.2 -C.sub.6 alkenyl, C.sub.1 -C.sub.6 alkylamino, C.sub.1 -C.sub.6 alkoxy, phenyl, aminophenyl, substituted phenyl or substituted aminophenyl and the substituents are of one or more of the following C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy, halogen or trifluoromethyl;
• R.sub.7 is C.sub.1 -C.sub.25 alkyl, C.sub.2 -C.sub.25 alkenyl, phenyl or substituted phenyl and the substituents are C.sub.1 -C.sub.20 alkyl, C.sub.1 -C.sub.20 alkoxy, halogen or trifluoromethyl;
• (B) R.sub.1 is one or more substituents of the aromatic ring which may be the same or different and is
• (i) C.sub.1 -C.sub.25 alkyl, C.sub.2 -C.sub.25 alkenyl, C.sub.1 -C.sub.25 alkoxy,
• C.sub.2 -C.sub.25 alkenyloxy, C.sub.1 -C.sub.25 thioalkyl, phenyl, phenoxy, substituted phenyl or substituted phenoxy wherein the substituents are C.sub.1 -C.sub.20 alkyl, C.sub.1 -C.sub.20 alkoxy, halogen, or trifluoromethyl;
• (ii) halogen, trifluoromethyl, cyano, or nitro;
• (iii) --CO.sub.2 R.sub.7, --CONHR.sub.7, --OCONHR.sub.7, or --NHCOR.sub.7 wherein R.sub.7 is as previously described above;
• (C) the moiety R.sub.2 is one or more substituents of the pyridine ring which may be in any position and are hydrogen, C.sub.1 -C.sub.5 alkyl, C.sub.1 -C.sub.5 alkoxy, or halogen;
• (D) the heterocycle is bonded to the X-group at optionally the 2, 3, or 4 position.
• (E) the group R.sub.3 is C.sub.1 -C.sub.8 alkyl, C.sub.1 -C.sub.8 halogen (bromine, chlorine or fluorine) substituted alkyl, hydrogen, or N-oxide;
• and
• (F) Z.sup..crclbar. represents a pharmacologically acceptable anion.