Solvent-free synthesis for imidazole-1-yl-acetic acid hydrochloride: an intermediate for zoledronic acid

Abstract

A convenient and environmentally-friendly protocol for the preparation of imidazol-1-yl-acetic acid hydrochloride is described <em>via</em> solvent-free <em>N</em>-alkylation of imidazole by <em>tert</em>-butyl chloroacetate, the obtained imidazol-1-yl-acetic acid <em>tert</em>-butyl ester was hydrolyzed in water and treated with hydrochloric acid to get imidazol-1-yl-acetic acid hydrochloride in good yields. Unlike the previously reported methods, this two step process is completely free from the use of hazardous solvents, besides, it has high yielding and been characterized by simple and easy work-up procedure. Imidazol-1-yl-acetic acid hydrochloride produced by the described method is converted into zoledronic acid monohydrate of medicinal use.