摘要 |
Compounds of the formula <IMAGE> and pharmaceutically acceptable non-toxic acid addition salts thereof, in which R is hydrogen, methyl, ethyl, cyclopropylmethyl, or allyl; A is a residue of a D-amino acid selected from the group consisting of Ala, Abu, Nva, Val, Nle, Leu, Ile, Gly(Al), Gly(Cp), Met, Cys(Me), Met(O), Cys(Me) (O), Ser, Thr, and Hse; R1 is C1-C3 primary alkyl, cyclopropylmethyl, allyl, ethylthiomethyl, 2-fluoroethyl, or propargyl; X is bromo, iodo, chloro, methyl, trifluoromethyl, or methoxy; and Z is -CH2OR2, <IMAGE> in which R2 is hydrogen, acetyl, or acetoxymethyl and R3 is C1-C3 alkyl; are useful analgesic agents. |