1-Acyl-substituted piperidine derivatives

Claim 2

A compound of formula (I): or a salt or solvate thereof in which R.CO is an acyl group in which R is of formula (II) in which R₃ is Br, NO₂ or CF₃; and, R₁ and R₂ are independently C 1-6 alkyl or together form a C 3-6 polymethylene or alkylene group.

Claim 3

A compound according to claim 1, in which each of R₁ and R₂ is methyl, ethyl, propyl, butyl, pentyl or hexyl.

Claim 4

A compound according to claim 1, in which R₁ and R₂ together form a propylene, butylene, pentylene or hexylene group, or a -CH₂-CH=CH-CH₂- group.

Claim 5

A compound according to any one of claims 1 to 3 in which R₃ is at the meta- or para-position on the phenyl ring.

Claim 6

A compound according to any one of claims 1 to 4 in the form of an (S)-enantiomer.

Claim 7

A compound selected from: (2R,S)-1-(3-nitrophenylacetyl)-2-(1-pyrrolidinyl­methyl)piperidine hydrochloride; (2R,S)-1-(3-trifluoromethylphenylacetyl)-2-(1-­pyrrolidinylmethyl)piperidine hydrochloride hemihydrate; (2S)-1-(4-trifluoromethylphenylacetyl)-2-(1-­pyrrolidinylmethyl) piperidine hydrochloride sesquihydrate; (2R,S)-1-(4-nitrophenylacetyl)-2-(1-pyrrolidinyl­methyl)piperidine hydrochloride; (2R,S)-1-(4-trifluoromethylphenylacetyl)-2-(1-­pyrrolidinylmethyl)piperidine hydrochloride; (2R,S)-1-(4-bromophenylacetyl)-2-(1-pyrrolidinyl­methyl)piperidine hydrochloride; (2R,S)-1-(3-nitrophenylacetyl)-2-dimethylamino­methyl piperidine hydrochloride; (2R,S)-1-(3-trifluoromethylphenylacetyl)-2-­dimethylamino-methyl piperidine hydrochloride.

Claim 8

A compound selected from: (2R,S)-1-(3-nitrophenylacetyl)-2-(1-pyrrolidinyl­methyl)piperidine hydrochloride; (2R,S)-1-(3-trifluoromethylphenylacetyl)-2-(1-­pyrrolidinylmethyl)piperidine hydrochloride hemihydrate; (2S)-1-(4-trifluoromethylphenylacetyl)-2-(1-­pyrrolidinylmethyl) piperidine hydrochloride sesquihydrate; (2R,S)-1-(4-nitrophenylacetyl)-2-(1-pyrrolidinyl­methyl)piperidine hydrochloride; (2R,S)-1-(4-trifluoromethylphenylacetyl)-2-(1-­pyrrolidinylmethyl)piperidine hydrochloride; (2R,S)-1-(4-bromophenylacetyl)-2-(1-pyrrolidinyl­methyl)piperidine hydrochloride; (2R,S)-1-(3-nitrophenylacetyl)-2-dimethylamino­methyl piperidine hydrochloride; (2R,S)-1-(3-trifluoromethylphenylacetyl)-2-­dimethylamino-methyl piperidine hydrochloride.

Claim 9

A process for the preparation of a compound according to any one of claims 1 to 6, which comprises reacting a compound of formula (III): in which R₁ʹ and R₂ʹ are R₁ and R₂ as defined for formula (I) or a group or atom convertible to R₁ and R₂, with a compound of formula Rʹ- -OH or an active derivative thereof, in which Rʹ is R as defined for formula (I) or a group convertible to R, to form a compound of formula (Ia) and then performing one or more of the following steps: a) where Rʹ, R₁ʹ or R₂ʹ and other than R, R₁ and R₂, converting Rʹ, R₁ʹ or R₂ʹ to R, R₁ or R₂ to obtain a compound of formula (I), b) where Rʹ, R₁ʹ and R₂ʹ are R, R₁ and R₂, converting one R, R₁ or R₂ to another R, R₁ or R₂ to obtain a compound of formula (I), c) forming a salt and/or solvate of the obtained compound of formula (I).

Claim 10

A process according to claim 7, in which the active derivative of Rʹ- -OH is an acid chloride or acid anhydride.

Claim 11

A pharmaceutical composition comprising a compound according to any one of claims 1 to 6, and a pharmaceutically acceptable carrier.

Claim 12

A composition according to claim 9 in unit dosage form.

Claim 13

A compound according to any one of claims 1 to 6, for use as an active therapeutic substance.

Claim 14

A compound according to any one of claims 1 to 6 for use in the treatment of pain.

Claim 15

The use of a compound according to any one of claims 1 to 6, in the manufacture of a medicament for the treatment of pain.