95058-92-7Relevant articles and documents
Preparation method of gemcitabine key intermediate
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Paragraph 0021; 0025-0038, (2021/11/06)
The invention relates to a preparation method of a gemcitabine key intermediate, and belongs to the technical field of drug intermediate synthesis. In order to solve the problems of high reaction condition requirements and high raw material cost in the prior art, the invention provides a preparation method of a gemcitabine key intermediate, which is characterized by comprising the following steps of: adding ethyl difluorochloroacetate, magnesium metal and a silanization reagent into a polar organic solvent for reaction to obtain an intermediate silyl enol ether; and under the action of Lewis acid, carrying out an aldol condensation reaction on the silyl enol ether and a compound R-glyceraldehyde acetonide as shown in a formula Vto obtain a corresponding product, namely, a gemcitabine key intermediate. According to the method, a target product with high chiral purity and yield can be effectively generated, the product yield reaches 85% or above, and the chiral purity of the product reaches 95% or above.
Novel preparation method for gemcitabine hydrochloride
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, (2018/04/21)
The invention discloses a preparation method for gemcitabine hydrochloride. The preparation method comprises the steps: carrying out condensation, cracking and addition on D-mannitol serving as an initial raw material, and protecting hydroxyl by TESC1 to prepare an intermediate; and after carrying out condensation on the intermediate and cytosine under the catalysis of chiral phosphoric acid, carrying out salification to prepare gemcitabine hydrochloride. The preparation method has the advantages that the reaction steps are reduced, and the cost is reduced. Due to the use of the chiral phosphoric acid, the proportion of a required beta structure is greatly increased, the ratio of beta to alpha can reach 9:1, and the yield is increased. The chiral phosphoric acid belongs to an organic acidand is recyclable, little to environment pollution and particularly suitable for industrial production of gemcitabine hydrochloride.
STEREOSELECTIVE SYNTHESIS OF BETA-NUCLEOSIDES
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Page/Page column 8, (2012/10/18)
A process of stereoselectively synthesizing β-nucleoside of formula (I), e.g., 2'-deoxy-2,2'-difluorocytidine, is described. The process includes reacting a tetrahydrofuran compound of the following formula: in which wherein R1, R2, R3, R4, and L as defined in the specification, with a nucleobase derivative in the presence of an oxidizing agent.
NOVEL SYNTHESIS OF BETA-NUCLEOSIDES
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Page/Page column 6, (2009/05/28)
This invention relates to a process of stereoselectively synthesizing β-nucleoside, e.g., 2′-deoxy-2,2′-difluorocytidine.
PROCESS FOR PREPARING OF 2'-DEOXY-2'2'-DIFLUOROCYTIDINE
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Page/Page column 22, (2008/12/04)
Disclosed is a method for preparing 2'-deoxy-2',2'-difluorocytidine of Formula I comprising, preparing an optically pure 3R-hydroxypropane amide compound of Formula VIII from an optical ester compound of Formula IX using an optically active chiral amine,
PROCESS FOR PREPARING GEMCITABINE AND ASSOCIATED INTERMEDIATES
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Page/Page column 24-25, (2008/06/13)
Provided is a process for preparing gemcitabine and intermediates useful in the production of gemcitabine. Exemplary intermediates include mixtures of D-erythro and D-threo diastereomers of ethyl 3-(N-carbamoyloxy)-2,2-difluoro-3-(2,2-dimethyldioxolan-4-yl)propionates, from which a preferred isomer can be separated, e.g., by selective crystallization, in accordance with the invention. Also provided are novel alkyl (D-erythro)-3-hydroxy-2,2-difluoro-3-(2,2-dimethyldioxolan-4-yl)propionate intermediates, and novel ribo lactones, which can be used for producing gemcitabine.
AN IMPROVED ONE POT PROCESS FOR MAKING KEY INTERMEDIATE FOR GEMCITABINE HCL
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Page/Page column 12; 15, (2010/11/27)
An improved one pot process for preparing 2-deoxy-D-erythro-2,2-difluoro-pentafuranose-1-ulose-3,5-dibenzoate of Formula (I) comprising hydrolysis of (erythro:threo) alkyl-3-dioxalan-4-yl-2,2-difluoro-3-hydroxy propionate of Formula (III) where alkyl group is having C1-C4 number of carbon atoms using a mild acid and selectively isolating 2-deoxy-D-erythro-2,2-difluoro-pentafuranose-1-ulose-3,5-dibenzoate from the mixture of erythro and threo enantiomers using ethyl acetate, ethylene dichloride and diisopropyl ether as solvents with improved yield and purity.
METHOD FOR THE PREPARATION OF D-ERYTHRO-2,2-DIFLUORO-2-DEOXY-1-OXORIBOSE DERIVATIVE
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Page/Page column 11-12, (2010/02/15)
3R-carboxylate enantiomer derivative of formula (III) can be prepared easily and selectively by the method of the present invention, and a highly pure D-erythro-2,2-difluoro-2-deoxy-1-oxoribose derivative can be prepared efficiently from the compound of formula (III) as an intermediate.
STEREOSELECTIVE SYNTHESIS OF β-NUCLEOSIDES
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Page/Page column 9-10, (2008/06/13)
This invention relates to a process for stereoselectively preparing a nucleoside of the following formula: wherein R3, R4, and B are defined herein. The process includes reacting a furanose compound with a nucleobase in the presence
Deoxyribonolactone lesion in DNA: Synthesis of fluorinated analogues
Crey, Caroline,Dumy, Pascal,Lhomme, Jean,Kotera, Mitsuharu
, p. 1093 - 1095 (2007/10/03)
Mono- and difluorinated derivatives of 2-deoxyribonolactone were synthesized using diastereoselective Reformatski reaction as a key step.