FOERFARANDE FOER FRAMSTAELLNING AV TERAPEUTISKT AKTIVA BENSHYDRYLOXIETYLPIPERAZINDERIVAT

Derivatives, of formula: in which: R1, R2, R3 and R4 independently of each other denote a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group or the trifluoromethyl group; n is an integer in between 1 and 6 inclusive; R5 and R6 denote, one a hydrogen atom and the other a substituted or unsubstituted benzoyl group; or R5 and R6 form, with the nitrogen atom to which they are bonded, a substituted or unsubstituted 5- or 6-membered heterocyclic group chosen from the following groups: succinimidyl, 4-phenylsuccinimidyl, phthalimidyl, naphthalimidyl, phthalimidinyl, 3-hydroxyphthalimidinyl, 2-oxobenzimidazolinyl, 3-benzyl-2-oxobenzimidazolinyl, 1,2,3,4-tetrahydro-2,4-dioxoquinazolinyl, 3,4-dihydro-4-oxoquinazolinyl, 3,4-dihydro-4-oxo-2-methylquinazolinyl, 3,7-dihydro-1,3-dimethyl-2,6-dioxo-1H-purinyl, 3,7-dihydro-3,7-dimethyl-2,6-dioxo-1H-purinyl. The invention also relates to processes for obtaining the said derivatives and to pharmaceutical compositions containing them. The said derivatives exhibit an antihistaminic activity without any sedative component.