IMPROVED PROCESS FOR THE PREPARATION OF STRONTIUM RANELATE HYDRATES AND NEW POLYMORPHIC FORM OF MONOHYDRATE

摘要

The present invention relates to an improved process for preparation of pure strontium ranelate hydrates (Ia-c) by using the intermediates, amino dimethyl ester (II) and tetramethyl ester (III), which are prepared by novel methods. The present invention also relates to a new crystalline polymorphic form of strontium ranelate monohydrate Form F, and process for the preparation thereof. Formula (Ia-c) : Ia- Strontium ranelate octahydrate: n=8 Ib- Strontium ranelate tetrahydrate: n=4 Ic- Strontium ranelate monohydrate: n=1 Formula (II) and Formula (III).