Novel antihistamines, process for their preparation and pharmaceutical compositions containing them

Claim 1

Process for the preparation of compounds of the general formula 1 wherein A represents the group of atoms required for completing a fused aromatic 5- or 6-membered heterocyclic ring or a fused benzene ring; B represents the group of atoms required for completing a fused pyridine, benzene or X-substituted benzene ring wherein X is halogen, with the proviso that,when A defines a nitrogen-containing heterocyclic ring, then B defines a fused benzene or X-substituted benzene ring; Z represents a single bond or a substituted or unsubstituted methylene or ethylene group, the substituent being an oxo or hydroxy group, or Z represents vinylene; R 2 represents hydrogen or an alkyl group having I to 3 carbon atoms and R 3 represents,hydrogen, or R 2 and R 3 form together a second bond; R 4 represents hydrogen and R 1 represents an alkyl group having 1 to 6 carbon atoms, or R 1 and R 4 form together a second bridge -(CH 2 ) 2 - between the carbon atom and the nitrogen atom to which they are attached; p represents 1 or 2; and Y represents either of the groups -COOR 7 and -SO 2 R 8 wherein R 7 represents alkyl, cycloalkyl,-cycloalkyl-alky, alkenyl , phenyl, phenylloweratkyl 1 or 2-, 3- or 4-pperidyl I' and R 8 represents alkyl, cycloalkyl, cycloalkylalkyl, alkenyl, phenyl or phenylloweralkyt, whereby the alkyl, cycloalkyl, cycloalkylalkyl and alkenyl groups represented by R 7 may optionally be substituted by the group wherein R 5 and R 6 each represent hydrogen or an alkyl group having 1 to 6 carbon atoms, the piperidyl groups represented by R 7 may be substituted at the nitrogen atom by a lower alkyl group having 1 to 4 carbon atoms, and whereby the phenyl groups and the phenyl moiety of the phenylloweralkyl groups represented by R 7 and/or R 8 may be substituted by halogen or lower alkyl having 1 to 4 carbon atoms, characterized in that a compound of the general formula III wherein A,B,Z, R 1 ,R 2 ,R 3 ,R 4 and p are as defined in claim l and Y' represents a replaceable group, with a compound of formula IV wherein Y is as de fined in claim I and T represents a group capable of being eliminated together with Y', and that, if desired, a so obtained compound of formula I is transferred into another compound of formula I by transesterification of the group Y.