Phenyl 5-tert-butylisoxazol-3-ylcarbamate → 1-(5-Tert-butyl-isoxazol-3-yl)-3-{4-[7-(2-chloro-ethoxy)-benzo[d]imidazo[2,1-b]thiazol-2-yl]-phenyl}-urea

Participants

Reaction Steps

A mixture of 7-(2-chloro-ethoxy)-2-(4-amino-phenyl)-benzo[d]imidazo[2,1-b]thiazole (1 equivalent) and phenyl 5-tert-butylisoxazol-3-ylcarbamate, prepared as described in WO 2006/082404 A1 (1 equivalent) in anhydrous THF is stirred at selected temperatures between rt and 50° C. until the reaction is substantially complete as monitored by LCMS or TLC. The mixture is concentrated under reduced pressure and the residue is partitioned between water and either dichloromethane or a mixture of dichloromethane and isopropanol. The separated aqueous layer is further extracted with dichloromethane or a mixture of isopropanol and dichloromethane, and the combined organic layers are dried over magnesium sulfate, filtered, and concentrated under reduced pressure. The residue is purified by silica gel flash chromatography to afford 1-(5-tert-butyl-isoxazol-3-yl)-3-{4-[7-(2-chloro-ethoxy)-benzo[d]imidazo[2,1-b]thiazol-2-yl]-phenyl}-urea.

Provenance & Evidence