874633-76-8

Upstream product

• 2524-64-3 chlorophosphoric acid diphenyl ester 

Downstream Products

• 874633-78-0 5-O-benzoyl-2-deoxy-2,2-difluoro-3-O-(p-phenylbenzoyl)-α-D-ribofuranosyl bromide 

Relevant academic research and scientific papers

An efficient large-scale synthesis of gemcitabine employing a crystalline 2, 2-difluoro-α-ribofuranosyl bromide

An efficient large-scale synthesis of gemcitabine was achieved without chromatography or fractional crystallization. The key steps include stereospecific conversion of a novel β-ribofuranosyl phosphate into a highly crystalline a-ribofuranosyl bromide and coupling of the α-ribofuranosyl bromide and trime- thylsilyl cytosine to produce a β-nucleoside. p-Phenylbenzoyl group was introduced for the protection of one of hydroxy groups in order to enhance the crystallinity of intermediates. Continuous removal of trimethylsilyl bromide, generated during the coupling reaction, by distillation from the reaction medium substantially enhanced the β-selectivity of the crucial coupling reaction.

Method for the Preparation of 2'-Deoxy-2',2'-Difluorocytidine

This invention relates to an improved method for stereoselectively preparing 2￠￥-deoxy-2￠￥,2￠￥-difluorocytidine of formula (I), which comprises the steps of reacting a 1-halo ribofuranose compound of formula (III) with a nucleobase of formula (IV) in a solvent to obtain a nucleoside of formula (II) with removing the silyl halide of formula (V) produced during the reaction; and deprotecting the nucleoside of formula (II) to obtain 2￠￥-deoxy-2￠￥,2￠￥-difluorocytidine of formula (I).

METHOD FOR THE PREPARATION OF 2#-DEOXY-2#,2#-DIFLUOROCYTIDINE

This invention relates to an improved method for stereoselectively preparing 2′-deoxy-2′,2′-difluorocytidine of formula (I), which comprises the steps of reacting a 1-halo ribofuranose compound of formula (III) with a nucleobase of formula (IV) in a solvent to obtain a nucleoside of formula (II) with removing the silyl halide of formula (V) produced during the reaction; and deprotecting the nucleoside of formula (II) to obtain 2′-deoxy-2′,2′-difluorocytidine of formula (I).

METHOD FOR THE PREPARATION OF 2'-DEOXY-2',2'-DIFLUOROCYTIDINE

This invention relates to an improved method for stereoselectively preparing 2￠￥-deoxy-2￠￥,2￠￥-difluorocytidine of formula (I), which comprises the steps of reacting a 1-halo ribofuranose compound of formula (III) with a nucleobase of formula (IV) in a solvent to obtain a nucleoside of formula (II) with removing the silyl halide of formula (V) produced during the reaction; and deprotecting the nucleoside of formula (II) to obtain 2￠￥-deoxy-2￠￥,2￠￥-difluorocytidine of formula (I).

1-α-HALO-2,2-DIFLUORO-2-DEOXY-D-RIBOFURANOSE DERIVATIVES AND PROCESS FOR THE PREPARATION THEREOF

1-α-halo-2,2-difluoro-2-deoxy-D-ribofuranose derivative of formula (I) having the 3-hydroxy group protected with a biphenylcarbonyl group is a solid which can be easily purified by a simple procedure such as recrystallization, and therefore, it can be adv