| abstract |
Compounds of the general formulan and pharmaceutically acceptable non-toxic acid addition salts thereof, in which L and D, when applicable, define the chirality;n R 1 and R 2 independently are hydrogen or C 1 -C 3 primary alkyl; R 3 is C 1 -C 3 primary or secondary alkyl or-CH 2 CH 2 -S-CH 3 ; R 4 is hydrogen or C 1 -C 3 primary alkyl; R 5 is hydrogen or C 1 -C 3 primary alkyl; Y is hydrogen or acetyl; and Zisn -CH 2 OH, or -CN; subject to the limitation that one of R 4 and R, is C 1 -C 3 primary alkyl and the other is hydrogen; are useful analgesic agents. |