Benzimidazole deriv. - for use as anti-allergic agent

摘要

1-(4-Fluorophenyl methyl) N-(1-(2-(4-methoxyphenyl)ethyl) 4-piperidinyl) 2-amino benzimidazole is made by (a) cyclising 2-amino (N-4-fluorophenyl methyl) aniline with urea in organic solvent, e.g. triglyme, at 110-220 deg. C; (b) treatment of the prod. with phosphoryl chloride and hydrochloric acid under reflux; (c) reaction with 4-amino piperidine 1-carboxylic acid ethyl ester; and (d) condensn. of the 1-(4-fluorobenzyl) 2-(4-piperidinylamino) benzimidazole formed with p-methoxyphenyl ethyl methyl sulphonate in hot dimethyl formamide in presence of Na2CO3 and KI.