| abstract |
Compounds of the formula [R-Tyr-A-Gly-(N-R1)Phe(p-Y)-X]2-(CH2)n in which R is hydrogen or methyl; A is the residue of a D-amino acid selected from the group consisting of Ala, Abu, Ser, Thr, and Met; R1 is hydrogen, C1-C3 primary alkyl, cyclopropylmethyl, or allyl; Y is hydrogen or fluoro; n is an integer from 1 to 10; and X is -NH- or a group of the formula <IMAGE> in which R2 is hydrogen or C1-C3 primary alkyl; R3 is phenyl, 2-methylthioethyl, or isobutyl; or R2 and R3 taken together are -CH2-CH2-CH2-; subject to the limitation that, when R2 is other than hydrogen, R1 is hydrogen; are useful analgesic agents. |