Process for preparing hexahydro-11 (eq)-CH2 CH2 COR5 -2,6-methano-3-benzazocines

Claim 1

The process for preparing a compound having the formula ##STR12## where: R 1 is hydrogen, lower-alkyl, lower-alkenyl, lower-alkynyl, halo-lower-alkenyl, cycloalkyl, cycloalkyl-lower-alkyl, 2- or 3-furylmethyl, or such 2- or 3-furylmethyl substituted on the unsubstituted ring carbon atoms by from one to three methyl groups, phenyl-lower-alkyl, or phenyl-lower-alkyl substituted in the phenyl ring by from one to two members of the group consisting of halogen, lower-alkyl, hydroxy, lower-alkanoyloxy, lower-alkoxy, lower-alkylmercapto, trifluoromethyl, amino, lower-alkanoylamino or a single methylenedioxy attached to adjacent carbon atoms; R 2 , r 2 ', r 2 " and R 2 '" are each hydrogen, or three of them are hydrogen and the fourth is halogen, lower-alkyl, hydroxy, lower-alkanoyloxy, lower-alkoxy, lower-alkylmercapto, trifluoromethyl, nitro, amino, lower-alkanoylamino, lower-alkoxy-carbonylamino or phenyl, or two of the adjacent such groups together are methylenedioxy; R 3 is hydrogen or lower-alkyl; R 4 is hydrogen, lower-alkyl, lower-alkoxy-lower-alkyl, hydroxy-lower-alkyl, lower-alkylthio-lower-alkyl, lower-alkyl-sulfinyl-lower-alkyl, phenylthio-lower-alkyl, phenylsulfinyl-lower-alkyl, lower-alkenyl or halo-lower-alkyl, or R 3 and R 4 together are divalent lower-alkylene, --(CH 2 ) n --, where n is one of the integers 3 or 4; R 5 is lower-alkyl, lower-alkylthio-lower-alkyl, lower-alkoxy-lower-alkyl, lower-alkoxy, cycloalkyl, cycloalkyl-lower-alkyl, 2- or 3-furyl, 2- or 3-furyl-(CH 2 ) m , where m is an integer from 2 to 4, or such 2- or 3-furyl or 2- or 3-furyl-(CH 2 ) m substituted on the unsubstituted ring carbon atoms by from one to three methyl groups, phenyl, phenyl-(CH 2 ) m , or phenyl or phenyl-(CH 2 ) m substituted in the phenyl ring by from one to two members of the group consisting of halogen, lower-alkyl, hydroxy, lower-alkanoyloxy, lower-alkoxy, lower-alkyl-mercapto, trifluoromethyl, amino, lower-alkanoylamino or a single methylenedioxy attached to adjacent carbon atoms which comprises heating, with formic acid in an inert organic solvent or with a benzyl-di-lower-alkylammonium formate or a tri-lower-alkylammonium formate, a compound having the formula ##STR13## where R 1 , R 2 , R 2 ', R 2 ", R 2 '", R 3 , R 4 and R 5 have the meanings given above, and Alk is lower-alkyl.