- Preparation method of capecitabine intermediate
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The invention discloses a preparation method of a capecitabine intermediate 1, 2, 3-O-triacetyl-5-deoxy-D-furanoside, which belongs to the technical field of medicinal chemistry. According to the invention, D-ribose (a compound I) is used as an initial raw material, and is subjected to a protective group reaction with methanol and acetone under the catalysis of solid acid, 1, 2, 3-hydroxyl is protected to obtain a compound II, then the compound II and thionyl chloride are subjected to a chlorination reaction, hydroxymethyl is changed into chloromethyl, a compound III is obtained, the compoundIII is subjected to a reduction reaction through platinum/carbon catalytic hydrogenation to obtain a compound IV, the compound IV is subjected to acidic hydrolysis to obtain a compound V, and the compound V is subjected to acetylation to obtain a target compound VI. The whole process is short in reaction step and high in economy; side reactions are few, and product purity is high; no wastewater isgenerated in the first three steps, so that the method is more environment-friendly; and the method is beneficial to industrial production of the capecitabine intermediate 1, 2, 3-O-triacetyl-5-deoxy-D-furanoside.
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- Preparation method of high-purity capecitabine key intermediate
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The invention discloses a preparation method of a high-purity capecitabine key intermediate. The preparation method comprises the following steps: taking D-ribose as an initial raw material, performing hydroxyl protection, 5-site tosylation, reduction, deprotection and acetylation to obtain high-purity 1,2,3-O-triacetyl-5-deoxo-D-ribose, wherein the 5-site tosylation reaction is carried out in anorganic solvent 1 by adopting inorganic base 1. Meanwhile, the acetylation reaction is carried in the presence of alkali 2 by taking water as a reaction solvent and taking 4-dimethylamiopryidine as acatalyst. The preparation method disclosed by the invention is mild in reaction conditions, high in yield, economic and effective, the purity of the prepared 1,2,3-O-triacetyl-5-deoxo-D-ribose can reach 99.0%, the alpha-isomer is small in content even is not detected, and the preparation method is applicable to large-scale industrial production.
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- Safe and Alternate Process for the Reductions of Methanesulfonates: Application in the Synthesis of 1,2,3-Triacetyl-5-deoxy-d-ribofuranoside
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Diethylene glycol dimethyl ether, diglyme, and 1,2-bis(2-methoxyethoxy)ethane, triglyme, are found to be suitable and safe alternate solvents to DMSO for the reduction of methanesulfonate in sodium borohydride. Addition of anhydrous lithium chloride led to the complete reduction of methanesulfonate esters to the corresponding alkanes in the presence of sodium borohydride in these solvents (diglyme and triglyme). This protocol is useful in the preparation of 1,2,3-triacetyl-5-deoxy-d-ribofuranoside, 7, a key intermediate of Capecitabine, 1, on the commercial scale.
- Mekala, Nagaraju,Moturu, Murthy V.R.K.,Dammalapati, Rao V.L.N.,Parimi, Atchuta R.
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p. 609 - 614
(2016/04/04)
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- Concise total synthesis of two marine natural nucleosides: Trachycladines A and B
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We report the first total synthesis of trachycladines A (10 steps, 34.2% overall yield) and B (11 steps, 35.0% overall yield) by using 5-deoxy-1,2,3-tri-O-acetyl-β-D-ribofuranose as the starting material. The critical step was the SnCl4 assisted regio- and steroselective deprotection of perbenzylated 1-O-methyl-5-deoxyribofuranose. The enzyme adenylate deaminase (EC 3.5.4.6) was successfully applied to the chemoenzymatic synthesis of trachycladines B.
- Ding, Haixin,Li, Wei,Ruan, Zhizhong,Yang, Ruchun,Mao, Zhijie,Xiao, Qiang,Wu, Jun
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p. 1681 - 1685
(2014/08/18)
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- PYRAZOLO[3, 4-D]PYRIMIDINE DERIVATIVES AS ANTIBACTERIAL COMPOUNDS
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This invention relates to 6-oxy-4-amino-1-(tetrahydrofuranyl)-1H- pyrazolo[3,4-d]pyrimidin-3(2H)-ones in free or salt form, e.g., compounds of formula (I) and formula (II) their use, e.g., in the treatment of bacterial infections and the process of preparing said compounds.
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Page/Page column 33
(2008/12/04)
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