Benzimidazole derivatives, process for the preparation thereof and
申请人:Kanebo, Ltd.
公开号:US04430343A1
公开(公告)日:1984-02-07
Novel benzimidazole derivatives of the formula: ##STR1## wherein R.sup.1 is an alkyl group having 1 to 3 carbon atoms, allyl group, propargyl group, or phenyl group; R.sup.2 is hydrogen atom or an alkyl group having 1 to 3 carbon atoms; and n is 2 or 3, or pharmaceutically acceptable acid addition salts thereof, which have excellent antihistaminic activities and are useful as antiallergics for various allergic diseases, and a process for the preparation thereof, and an antihistaminic composition containing the compound as an active ingredient.
A series of 2-(4-substituted-1-(homo)piperazinyl)benzimidazoles was prepared and tested for H1-antihistaminic activity in vitro and in vivo. Most of the compounds showed antihistaminic activity and some of the 1-[2-(substituted-oxy)ethyl] derivatives exhibited potent activity. In a structure-activity comparison it was found that the oxygen atom in the 2-(substituted-oxy)ethyl group at the 1-position