Cycloaliphatic compounds, analgesic compositions thereof and method of use thereof as analgesics

A compound of the formula (I):

• ##STR22## in which R.sub.1 represents a hydrogen atom, a halogen atom or a group OR.sub.2, in which R.sub.2 represents a hydrogen atom, an alkyl group containing 1 to 6 carbon atoms, an alkanoyl group containing 1 to 6 carbon atoms, an alkenoyl group containing 3 to 6 carbon atoms or a benzoyl group;
• R.sub.3 represents a hydrogen atom or an alkyl containing 1 to 6 carbon atoms, alkenyl containing 3 to 6 carbon atoms or a phenyl group;
• R.sub.4 and R.sub.5, which may be the same or different, each represents a hydrogen atom or an alkyl containing 1 to 6 carbon atoms, alkenyl containing 3 to 6 carbon atoms or alkynyl group containing 3 to 6 carbon atoms optionally substituted by a phenyl or cycloalkyl group containing 3 to 6 carbon atoms;
• or R.sub.4 and R.sub.5 together with the nitrogen atom to which they are attached form a saturated four to seven membered ring in which said nitrogen atom is the only heteroatom in said ring;
• with the provisos that, when R.sub.4 and R.sub.5 simultaneously represent hydrogen atoms, (i) when R.sub.1 represents a hydrogen atom, R.sub.3 does not represent a methyl group, and (ii) the compound of formula (I) is the .beta.-isomer, and its physiologically accepted salts.