5-aryl-3-azabicyclo[3.2.0]heptan-6-one acetals, and analgesic use

Abstract

Novel compounds are disclosed having the formula ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 are each individually selected from the class consisting essentially of hydrogen, hydroxy, chloro, bromo, an alkyl radical having up to 3 carbon atoms, an alkoxy radical having up to 3 carbon atoms, and trifluoromethyl, and any two or more of R.sub.1, R.sub.2 and R.sub.3 may be the same; R.sub.4 is selected from the class consisting essentially of hydrogen, an alkyl radical having up to 3 carbon atoms, an allyl radical having up to 4 carbon atoms, the cyclopropylmethyl radical or the phenethyl radical; and W and W' each represent a monovalent alkyl moiety having up to 3 carbon atoms or W-W' jointly represent a divalent moiety of the formula ##STR2## where n is an integer of 2 or 3, including individual optically active isomers, racemic mixtures thereof, and non-toxic pharmacologically-acceptable acid-addition salts thereof. Such compounds are useful as analgesics in mammals. They can be prepared by irradiating with ultra-violet light a mixture of a dialkoxyethylene and a maleimide of the formula ##STR3## to produce a 4,4-dialkoxy-N-alkyl-1-phenyl-1,2-cyclobutanedicarboximide, and chemically reducing the same. Three other processes of preparation are also described.