Process for the preparation of sorafenib and salts thereof

摘要

Methods for the synthesis of the N-carbamoyl imidazole (I) and its 1:1 adduct with imidazole are provided. Methods for the preparation of these crystalline intermediates in a high state of purity are also provided. These intermediates react cleanly under mild conditions to produce sorafenib in high yield and purity, without generating difficult-to-remove impurities.