Modulators of acetylcholine receptors

A pharmaceutical composition comprising a compound of the structure:

• ##STR10## and a pharmaceutically acceptable carrier therefor, optionally in the form of a pharmaceutically acceptable non-toxic acid addition salt, wherein:
• A is a 2 or 3 atom bridging species which forms part of a saturated or monounsaturated 6- or 7-membered ring including N.sup.7, C.sup.8, C.sup.9 and B, provided, however, that the ring formed by N.sup.7, C.sup.8, C.sup.9, A and B does not contain any covalent heteroatom-heteroatom single bonds, or any heteroatom-methylene-heteroatom relationships;
• B is selected from --O--, --S--, --NR.sup.10 --, wherein R.sup.10 is selected from hydrogen, lower alkyl, aryl, substituted aryl, alkylaryl, substituted alkylaryl, arylalkyl, substituted arylalkyl;
• or B is .dbd.N--, provided there is no double bond in the ring between A and B, or between B and C.sup.9 when there is a double bond between N.sup.7 and C.sup.8 ;
• R.sup.2, R.sup.4, R.sup.5 and R.sup.6 are each independently selected from hydrogen, alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, aryl, substituted aryl, alkylaryl, substituted alkylaryl, arylalkyl, substituted arylalkyl, heterocyclic, substituted heterocyclic, trifluoromethyl, halogen, cyano, nitro;
• --S(O)R', --S(O).sub.2 R' or --S(O).sub.2 NHR', wherein each R' is as defined above, provided, however, that when R.sup.2, R.sup.4, R.sup.5 or R.sup.6 is --S(O)R', R' is not hydrogen, alkenyl or alkynyl, and provided that when R.sup.2, R.sup.4, R.sup.5 or R.sup.6 is S(O).sub.2 NHR', R' is not alkenyl or alkynyl;
• --C(O)R", wherein R" is selected from hydrogen, alkyl, substituted. alkyl, alkoxy, alkylamino, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, aryl, substituted aryl, aryloxy, arylamino, alkylaryl, substituted alkylaryl, arylalkyl, substituted arylalkyl, heterocyclic, substituted heterocyclic or trifluoromethyl, provided, however, that the carbonyl functionality is not conjugated with an alkenyl or alkynyl functionality;
• --OR'", wherein R'" is selected from hydrogen, alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, aryl, substituted aryl, alkylaryl, substituted alkylaryl, arylalkyl, substituted arylalkyl, aroyl, substituted aroyl, heterocyclic, substituted heterocyclic, acyl, trifluoromethyl, alkylsulfonyl or arylsulfonyl, provided, however, that the --OR'" functionality is not conjugated with an alkenyl or alkynyl functionality;
• --NR'".sub.2, wherein each R'" is independently as defined above, or each R'" and the N to which they are attached can cooperate to form a 4-, 5-, 6- or 7-membered ring;
• provided, however, that the --NR'".sub.2 functionality is not conjugated with an alkenyl or alkynyl functionality;
• --SR"", wherein R"" is selected from hydrogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, aryl, substituted aryl, alkylaryl, substituted alkylaryl, arylalkyl, substituted arylalkyl, heterocyclic, substituted heterocyclic or trifluoromethyl, provided, however, that the --SR"" functionality is not conjugated with an alkenyl or alkynyl functionality;
• or
• --SiR'"".sub.3, wherein R'"" is selected from alkyl or aryl;
• R.sup.7 is selected from hydrogen, lower alkyl, aryl, substituted aryl, alkylaryl, or substituted alkylaryl, or R.sup.7 is absent when there is a double bond between N.sup.7 and C.sup.8 ;
• and
• R.sup.9 and R.sup.9a are each independently selected from hydrogen, lower alkyl, hydroxyalkyl, aryl, aryloxyalkyl, fluoro, trifluoromethyl, cyano, cyanomethyl, --OR', --NR'.sub.2, or --SR', wherein each R' is as defined above, provided, however, that neither the --NR'.sub.2 nor the --SR' functionality is conjugated with an alkenyl or alkynyl functionality;
• provided, however, that when A is a two atom bridging species, B is --O--, and R.sup.2, R.sup.4, R.sup.6, R.sup.7, R.sup.9 and R.sup.9a are hydrogen, R.sup.5 is not nitro;
• and when A is a two atom bridging species and B is --NH--, at least one of R.sup.2, R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.9 and R.sup.9a is not hydrogen.