STUDIES ON POTENT ANALGESICS VI MODIFICATION OF 4-NPROPIONYL GROUP OF cis-3METHYLFENT ANYL AND ANALGESIC ACTIVITY

A series of 4-N-acyl analogs of cis-3-methylfentanyl were synthesized and their analgesic activity and duration of action of some representative compounds were tested. In preliminary pharmacological tests all compounds in this series exhibited typical morphine-like action. The analgesic activity of compounds 1, 2, 3, 7, 17 was over 100 times more potent than that of morphine. The duration of analgesic action of compounds 4, 7, 17 was longer than that of both fentanyl and cis-3-methylfentanyl.Structure-activity relationships are briefly discussed.