143157-23-7

Upstream product

• 14631-20-0 4-N-Acetylcytosine 
• 134877-42-2 3,5-di-O-benzoyl-2-deoxy-2,2-difluoro-1-O-methanesulfonyl-D-erythro-pentofuranose 
• 122111-01-7 2-deoxy-2,2-difluoro-D-erythro-pentonic acid γ-lactone 3,5-dibenzoate 
• 1173824-58-2 (2R,3R)-2-((benzoyloxy)methyl)-4,4-difluoro-5-hydroxyoxolan-3-yl benzoate 
• 96472-73-0 bis(trimethylsilyl)-N-acetylcytosine 

Downstream Products

• 103882-84-4 2’-deoxy-2’,2’-difluoro-cytidine 

Relevant academic research and scientific papers

Process for the preparation of gemcitabine chlorohydrate

Disclosed is the preparation of 2-deoxy-D-erythro-2,2-difluororibofuranose-3,5-dibenzoate: a known intermediate for the preparation of Gemcitabine, by means of a reduction process; further disclosed is the purification of Gemcitabine by chromatography and the purification of Gemcitabine hydrochloride by crystallization techniques from ternary solvent mixtures. The main advantage of the invention is providing Gemcitabine hydrochloride with purity in conformity with the Pharmacopoeia requirements, as well as a process particularly convenient from the industrial point of view.

Stereospecific synthesis of 2-deoxy-2,2-difluororibonolactone and its use in the preparation of 2'-deoxy-2',2'-difluoro-β-D-ribofuranosyl pyrimidine nucleosides: The key role of selective crystallization

A stereospecific synthesis of 2'-deoxy-2',2'-difluorocytidine (gemcitabine), a potential anticancer agent, is described. The stereoselectivity was accomplished via two diastereoselective crystallizations, i.e. the crystallization of the key intermediate, difluororibonolactone 2a, and the crystallization of the hydrochloride salt of gemcitabine 16b from the anomeric mixture. Because of the availability of 2a in large quantities, other 2'-deoxy-2',2'-difluoropyrimidine nucleosides such as 2'-deoxy-2',2'-difluorouridine (19) were synthesized for structure-activity relationship studies.