EP1899328B1 — A process for the preparation of losartan derivatives by chlorination and reduction of the respective 1h-imidazole-5-carbaldehydes

USPTO Abstract

The invention provides a process for the preparation of a sartan derivative of formula (I): wherein R = C2-C7 straight or branched alkyl or C3-C9 cycloalkyl, or a pharmaceutically acceptable salt thereof, comprising the steps of chlorinating and reducing, in any order, a compound of formula (III): wherein R is defined as above to form a compound of formula (VI), wherein R is defined as above and then deprotecting said compound of formula (VI) to obtain the sartan derivative of formula (I), and optionally converting said sartan derivative into one of its pharmaceutically acceptable salts. A preferred embodiment of this invention is a process for the preparation of losartan and, particularly, its potassium salt.