N-(Pyrrolidinylalkyl)acetamide derivs. of formula (I) are new. R1 = Ar, 3-6C cycloalkyl or 4-8C cycloalkylalkyl； R2 = Ar； or R1+R2 = a gp. of formula (a)； R3 = H, OH, OA or A； R4 = A or Ph (opt. mono- or disubstd. by halo, OH, OA, CF3, NO2, NH2, NHA, NHCOA, NHSO2A or NA2)； R5 = OH or CH2OH； R6, R7 = H, halo, OH, OA, CF3, NH2, NHA, NA2, NHCOA, NHCONH2, NO2 or methylenedioxy； A = 1-7C alkyl； Ar = mono- or bicyclic aromatic residue (opt. contg. N, O or S), (opt. mono- to tri- substd. by A, halo, OH, OA, CF3, NH2, NHA, NA2, NHCOA and/or NHCONH2)； D = CH2, O, S, NH, NA, CH2, CH=CH, CH2NH, CH2NA or bond； halo = F, Cl, Br or I； with the exception of the cpd. N-methyl-N-Ä(1S)-1-phenyl-2-((3S)-3-hydroxypyrrolidin-1-yl)ethylÜ-2,2- diphenylacetamide hydrochloride (Ia). Also claimed is a compsn. contg. (I) and/or the glycolised (sic) derivs. of (I) or (Ia)； and the use of (Ia) to produce a pharmaceutical with kappa-opiate antagonist activity. Pref. (I) is N-methyl-N-Ä(1S)-1-phenyl-2-((3S)-3-hydroxypyrrolidin-1-yl)ethylÜ-2,2- diphenylacetamide.
