Benzimidazoline-2-oxo-1-carboxylic acid compounds useful as 5-HT 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: (I) wherein R is hydrogen, C1-6 alkyl, C2-6 alkenyl or C2-6 alkynyl; R1 is hydrogen; R2 is hydrogen, halogen or C1-6 alkoxy; Y is oxygen or N-R3 in which R3 is hydrogen; A is a group selected from: (a) (b) (c) (d) wherein p is 1; r is 0, 2 or 3: R4 is hydrogen; R5 is hydrogen, C1-6 alkyl, or R5 is a group of the formula -CR6=N-R7 wherein R6 is hydrogen, C1-4 alkyl or amino and R7 is hydrogen or C1-6 alkyl; or a pharmaceutically acceptable acid addition salt thereof. The processes for the preparation of the compounds of formula (I) as well as pharmaceutical compositions contained in them are also described.