Piperazine derivatives, their use as medicaments and process for preparation thereof

Abstract

The present invention relates to piperazine derivatives of formula wherein R represents a halogen atom or a C1-4 alkyl group; R1 represents hydrogen or a C1-4 alkyl group; R2 represents hydrogen, a C1-4 alkyl, C2-6 alkenyl_or a C3-7 cycloalkyl group; or R1 and R2 together with nitrogen and carbon atom to which they are attached respectively represent a 5-6 membered heterocyclic group; R3 represents a trifluoromethyl, a C1-4 alkyl, a C1-4 alkoxy, a trifluoromethoxy or a halogen group; R4 represents hydrogen, a (CH2)qR7 or a (CH2)rCO(CH2)pR7 group; R5 represents hydrogen, a C1-4 alkyl or a COR6 group; R6 represents hydrogen, hydroxy, amino, methylamino, dimethylamino a 5 membered heteroaryl group containing 1 to 3 heteroatoms selected from oxygen, sulphur and nitrogen or a 6 membered heteroaryl group containing 1to 3 nitrogen atoms; R7 represents hydrogen, hydroxy or NR8R9 wherein R8 and Rg represent independently hydrogen or C1-4 alkyl optionally substituted by hydroxy, or by amino; R10 represents hydrogen, a C1-4 alkyl I group or ,m is zero or an integer from 1 to 3; n is zero or an integer from 1 to 3; both p and r are independently zero or an integer from 1 to 4; q is an integer from 1 to 4; provided that, when R1 and R2 together with nitrogen and carbon atom to which they are attached respectively represent a 5 to 6 membered heterocyclic group, i) mis 1 or 2; ii) when m is 1, R is not fluorine and iii) when m is 2, the two substituents R are not both fluorine, and pharmaceutically acceptable salts. and solvates thereof. R10 together with R2 represents a a C3-7 cycloalkylgroup; m is zero or an integer from 1 to 3; n is zero or an integer from 1 to 3; both p and r are independently zero or an integer from 1 to 4; q is an integer from 1 to 4; provided that, when R1 and R2 together with nitrogen and carbon atom to which they are attached respectively represent a 5 to 6 membered heterocyclic group, i) mis 1 or 2; ii) when m is 1, R is not fluorine and iii) when m is 2, the two substituents R are not both fluorine, and pharmaceutically acceptable salts. and solvates thereof.