SYNTHESIS AND ANALGESIC ACTIVITY OF 3, 4-DICHLORO-N-METHYL-N- TRANS-2-(1-△³-PYRROLINYL )-CYCLOHEXYL-BENZENACETAMIDE HYDROCHLORIDE

3, 4-Dichloro-N-methyl-N-trans-2- (1-△³-pyrrolinyl)-cyclohexyl-benzenacetamide hydrochloride (K-Ⅱ) was synthesized from N-methyl-7-azabicyclo 4.1.0 heptane by treatment with 2,5-dihydropyrrole to give N-trans-2(1-△³-pyrrolinyl)-cyclohexyl-N-methylamine which was amidated with 3,4-dichlorophenyl-acetic acid. K-Ⅱ is an analogue of U-50488 H(K-Ⅰ), a known kappa receptor agonist.The results of animal tests showed that K-Ⅱ is 3 times as potent as K-Ⅰ as an analgesic in the mouse hot plate test and 5 times in the mouse writhing test and that the affinity of K-Ⅱ for kappa receptor may be higher than that of K-Ⅰ. The general behavioural effects of these two agents are similar in mice.