Substituted 1-phenethylpiperidine compounds used as inter alia analgesics

Substituted 1-phenethylpiperidine compounds of the general formula I

• 13
• in which
• X denotes a methylene (CH2) or carbonyl (C═O) group,
• R1 denotes an optionally at least mono-substituted aryl or heteroaryl residue,
• R2 denotes H, COR5, SO2R5, an optionally at least mono-substituted, saturated, branched or unbranched aliphatic C1-10 residue, an optionally at least mono-substituted, at least mono-unsaturated, branched or unbranched aliphatic C2-10 residue, an optionally at least mono-substituted, saturated or at least mono-unsaturated cycloaliphatic C3-8 residue, an optionally at least mono-substituted aryl or heteroaryl residue or an optionally at least mono-substituted aryl or heteroaryl residue attached via a C1-3 alkylene group,
• R3 and R4 each separately denote H or together denote a bond,
• R5 denotes an optionally at least mono-substituted, saturated, branched or unbranched aliphatic C1-10 residue, an optionally at least mono-substituted, at least mono-unsaturated, branched or unbranched aliphatic C2-10 residue, an optionally at least mono-substituted, saturated or at least mono-unsaturated cycloaliphatic C3-8 residue, an optionally at least mono-substituted aryl or heteroaryl residue or an optionally at least mono-substituted aryl or heteroaryl residue attached via a C1-3 alkylene group,
• as a free base or a corresponding physiologically acceptable salt and corresponding racemates, enantiomers and diastereomers.