New benzimidazoline-2-oxo-1-carboxylic acid derivatives useful as 5-nt receptor antagonists

New pharmacologically active benzimidazoline-2-oxo-1-carboxylic acid derivatives which are 5-HT receptor antagonists useful as antiemetic agents and as gastric prokinetic agents of the following formula: wherein R represents a hydrogen atom, C1-6 alkyl, C1-6 alkenyl or C1-6 alkynil; R1 and R2 may be at the same time or not a hydrogen atom, halogen, trifluoromethyl, C1-6 alkyl, C1-6 alkoxy, C1-6 alkylthio, C1-6 acyl, carboxyl, C1-6 alkoxycarbonyl, hydroxy, nitro, amino optionally C1-4 alkyl N-mono or di-substituted, C1-6 acylamino, C1-6 alkoxycarbonylamino, carbamoyl optionally C1-4 alkyl N-mono or di-substituted, cyano, C1-6alkylsulphinyl, C1-6 alkylsulphonyl, amino sulphonyl optionally C1-4 alkyl N-mono or di-substituted, C1-4 alkyl N-mono or di-substituted aminosulphonylamino, aminosulphonylamino; Y is oxygen or is N - R3 in which R3 is a hydrogen, a C1-6 alkyl or optionally substituted by one or more C1-6 alkoxy benzyl; A is a group selected from: wherein p is 0, 1; r is 0, 1, 2, 3; R4 is hydrogen atom or a C1-4 alkyl; R5 is a hydrogen atom, C1-6 alkyl, C3-8 cycloalkyl, C3-8 cycloalkyl C1-4 alkyl,substituted phenyl C1-4 alkyl or R5 is a group of formula wherein R6 is hydrogen atom, C1-4 alkyl or an amino group and R7 is hydrogen atom or C1-6 alkyl, tautomers thereof and acid addition salts of the aforesaid compounds. The processes for the preparation of the compounds of formula (I) as well as pharmaceutical compositions containing them are also described.