The present invention relates to novel derivatives of benzimidazole, their process of preparation as well as their use as medicaments.
The compounds according to the present invention correspond to the general formula I ##STR2## in which: R.sub.1 and R.sub.2, equal or different, represent a hydrogen atom, a halogen, a lower alkyl radical, a hydroxy radical, an alkoxy radical, an alkyl carboxylate radical, an aryl or substituted aryl,
n may have the values 0 or 1, PA0 m may have the values 2 to 4, PA0 X, Y, Z and W, equal or different, represent a nitrogen atom or a carbon atom linked to a hydrogen atom, a halogen or another alkyl, aryl, alkylcarbonyl, carboxy, hydroxyl, sulfo and alkylsulfonic radical.
In the scientific literature derivatives of benzimidazole are already known with different biological activities, like for example, analgesic and antiinflammatory activity (Japan Kokai 75, 126, 682), gastric antisecretory activity (EP 246,126 and EP 5129); antihistaminic activity (J. Jilek et al., Collect. Czech. Chem. Commun. 1988, 53, 870-83; U.S. Pat. No. 4,200,641; Drugs of the Future, VII; 10-1, 1982; R. Iemura et al., J. Med. Chem., 1987, 24, 31-37). The compounds according to the present invention are novel derivatives of benzimidazole, actually 1-(2-ethoxyethyl)-2-(alkylpiperazinylalkylazoles) benzimidazole. We have discovered that these novel derivatives have very good antihistaminic activity and they do not have side effects on the central nervous system.
The novel derivatives of general formula I may be prepared, according to the invention, according to any one of the following methods: