Maleimide derivatives of oxotremorine

A compound selected from those of the formulae II and IV:

• ##STR8## wherein R.sub.1 and R.sub.2 are independently selected from straight and branched (C.sub.1 -C.sub.6)alkyl;
• or R.sub.1 is selected from straight and branched (C.sub.1 -C.sub.6)alkyl and R.sub.2 is --(CH.sub.2).sub.n R.sub.9 where n=2-6 and R.sub.9 is selected from hydroxy, (C.sub.1 -C.sub.10)acyloxy, and trialkylsilyloxy or R.sub.1 and R.sub.2 taken together with their associated N(itrogen) are selected from the group consisting of pyrrolidine, piperidine and moieties of the formula:
• ##STR9## wherein R.sub.5 and R.sub.6 are independently selected from (C.sub.1 -C.sub.10)acyloxy, (C.sub.1 -C.sub.6)alkoxy, aroyloxy, substituted aroyloxy (wherein the substituting moiety is selected from hydroxy, halo, alkyl (C.sub.1 -C.sub.6) and alkoxy (C.sub.1 -C.sub.6), hydroxy, thio, (C.sub.1 -C.sub.6)alkylthio, (C.sub.1 -C.sub.6)alkyldithio, (C.sub.1 -C.sub.10)acylthio and hydrogen;
• and R.sub.7 and R.sub.8 are selected from hydrogen, substituted methyl wherein the substituting moiety is selected from hydroxy, halo, (C.sub.1 -C.sub.6) alkylsulfonyloxy and phenylsulfonyloxy with the proviso that only one R.sub.5, R.sub.6, R.sub.7, or R.sub.8 can be a substituent other than hydrogen;
• R.sub.3 is selected from hydrogen, straight and branched (C.sub.1 -C.sub.6)alkyl;
• R.sub.4 is selected from, straight and branched (C.sub.1 -C.sub.6) alkylthio;
• R.sub.10 is selected from (C.sub.1 -C.sub.6)alkyl;
• and the pharmacologically acceptable salts thereof.