Abstract: 1-Substituted-4-(1,2-diphenylethyl)piperazine derivatives of the formula: ##STR1## wherein X is 2- or 3-hydroxy, 2-methoxy, 3-methyl, 3-alkoxy having 1 to 4 carbon atoms, or 2- or 3-alkanoyloxy having 2 to 5 carbon atoms; R is allyl, 3-hydroxyisoamyl, 3-methyl-2-butenyl, 3-methyl-3-butenyl, propyl, an unsubstituted monocycloalkyl having 5 to 8 carbon atoms, 2-chlorophenyl, or a phenyl substituted by hydroxy or methoxy; with proviso that when X is a substituent at position 2, R is cyclohexyl and when X is 3-methyl, R is 2-methoxyphenyl or an unsubstituted monocycloalkyl having 6 to 8 carbon atoms, and their pharmaceutically acceptable salts, and the preparation thereof, and analgesic or antitussive compositions containing the same as the essentially active ingredient.

Abstract: 1-Substituted-4-(1,2-diphenylethyl)piperazine derivatives of the formula: ##STR1## wherein X is 2- or 3-hydroxy, 2-methoxy, 3-methyl, 3-alkoxy having 1 to 4 carbon atoms, or 2- or 3-alkanoyloxy having 2 to 5 carbon atoms; R is allyl, 3-hydroxyisoamyl, 3-methyl-2-butenyl, 3-methyl-3-butenyl, propyl, an unsubstituted monocycloalkyl having 5 to 8 carbon atoms, 2-chlorophenyl, or a phenyl substituted by hydroxy or methoxy; with proviso that when X is a substituent at position 2, R is cyclohexyl and when X is 3-methyl, R is 2-methoxyphenyl or an unsubstituted monocycloalkyl having 6 to 8 carbon atoms, and their pharmaceutically acceptable salts, and the preparation thereof, and analgesic or antitussive compositions containing the same as the essentially active ingredient.

Abstract: 1,2-Diphenylethanolamine derivatives of the formula: ##SPC1##Wherein R.sub.1 and R.sub.2 are each hydrogen, a halogen, nitro, hydroxy, an alkyl or methoxy; R.sub.3 is a group of the formula: ##SPC2##Wherein R.sub.4, R.sub.5 and R.sub.6 are each hydrogen, a halogen or methoxy and n is an integer of 0 to 3, or a pyridyl; and Z is hydroxy or an acyloxy; with proviso that when R.sub.1 and/or R.sub.2 are hydroxy, Z is hydroxy, and their pharmaceutically acceptable salts, which have excellent analgesic and anti-tussive activities, and a process for the preparation thereof.

Abstract: 1-Substituted-4-(1,2-diphenylethyl)piperazine derivatives of the formula: ##SPC1##Wherein X is hydroxy, methoxy, methyl or trifluoromethyl; and R is an unsubstituted monocycloalkyl group having 6 to 8 carbon atoms or 2-methoxyphenyl; provided that when X is hydroxy, R is cyclohexyl, and when X is trifluoromethyl, R is 2-methoxyphenyl,And their pharmaceutically acceptable salts, which have excellent analgesic, anti-tussive and anti-inflammatory activities, without undesirable side effect such as narcotic activity, and a process for the preparation thereof.