Isochem

Telik, Inc.

Hervé Lhermitte

Christian Picherit

Antoine Paris

Charles-Henri Vincent

Guyselaine Leclerc

Julien Grima

Provided herein are processes of preparing ezatiostat hydrochloride, and crystalline ezatiostat hydrochloride ansolvate form D.

Preparation of crystalline ezatiostat hydrochloride ansolvate form D

The invention relates to a method of preparing urethane-protected N-carboxyanhydrides of alpha amino acids. The inventive method enables the synthesis of urethane-protected N-carboxyanhydrides of alpha amino acids in the presence of a catalytic quantity of triethylene diamine without the addition of a tertiary amine-type base.

Method of obtaining urethane-protected N-carboxyanhydrides of alpha amino acids

According to the process of the invention, the hexahydropyridazine-3-carboxylic acid derivatives are prepared by reacting a compound of formula (II) with a compound of formula (III) in the presence of a base with a pK of greater than or equal to 8.5, in a ketone organic solvent, to obtain an intermediate compound that is not isolated and that is treated with a basic aqueous medium. By means of this process, the derivatives are obtained more quickly and more economically.

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Paris, France

Hervé Lhermitte