- Synthesis of an Oxathiolane Drug Substance Intermediate Guided by Constraint-Driven Innovation
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A new route was developed for construction of the oxathiolane intermediate used in the synthesis of lamivudine (3TC) and emtricitabine (FTC). We developed the presented route by constraining ourselves to low-cost, widely available starting materials - we refer to this as supply-centered synthesis. Sulfenyl chloride chemistry was used to construct the framework for the oxathiolane from acyclic precursors. This bond construction choice enabled the use of chloroacetic acid, vinyl acetate, sodium thiosulfate, and water to produce the oxathiolane.
- Burns, Justina M.,Gupton, B. Frank,Kashinath, K.,McQuade, D. Tyler,Snead, David R.,Stringham, Rodger W.
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supporting information
p. 2266 - 2270
(2020/11/23)
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- Synthetic method for lamivudine
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The invention provides a synthetic method for lamivudine. The synthetic method comprises the following steps: cheap easily-available dihaloacetic acid is used as a raw material, the dihaloacetic acidand L-menthol are subjected to condensation, hydrolysis is performed to obtain menthyl glyoxylate, the menthyl glyoxylate and 2,5-dihydroxy-1,4-dithiane are subjected to condensation, halogenation isperformed, the halogenated product and silanized cytosine are subjected to coupling, reduction is performed, the reduced product and salicylic acid are subjected to salt formation to obtain the a salicylate, and finally recrystallization is performed to obtain the optically-pure lamivudine. According to the method provided by the invention, the raw materials used in the whole synthetic process arecheap and easy to obtain, the synthetic process is simple, the synthetic conditions are mild, so that the synthetic costs of the lamivudine are greatly reduced; the raw material utilization rate andreaction selectivity are high, so that the yield of the obtained lamivudine is higher; and at the same time, a chiral substrate is easily removed during the synthesis, three waste (waste water, wastegas and solid waste) generated in the method are less, and the method is suitable for industrialized large-scale production of the lamivudine.
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- Emtricitabine synthesis method
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The invention provides an emtricitabine synthesis method, which comprises: carrying out condensation on cheap and easily available dihaloacetic acid as a raw material and L-menthol, hydrolyzing to obtain menthyl glyoxylate hydrate, condensing with 2,5-dihydroxy-1,4-dithiane, carrying out halogenation, coupling with silylated 5-flucytosine, reducing, carrying out salt forming with salicylic acid toobtain emtricitabine salicylate, and finally re-crystallizing to obtain optically pure emtricitabine. According to the present invention, the whole synthesis process has characteristics of inexpensive and easily available raw materials, simple synthesis process and mild synthesis conditions, such that the synthesis cost of emtricitabine is substantially reduced; various raw materials have characteristics of good reaction selectivity and high utilization rate, such that the yield of the obtained emtricitabine is high; and the chiral substrate is easily removed during the synthesis, and the generated three-waste pollutants are less, such that the method is suitable for industrial large-scale production of emtricitabine.
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- PROCESS FOR PRODUCING LAMIVUDINE AND EMTRICITABINE
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This invention provides for flow and batch synthesis processes for the production of Lamivudine and Emtricitabine, including flow and batch synthesis processes wherein at least of the synthesis steps are conducted in a solvent free environment.
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Page/Page column 12; 13; 14; 15; 17; 18
(2018/01/20)
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- A STEREOSELECTIVE PROCESS FOR PREPARATION OF 1,3-OXATHIOLANE NUCLEOSIDES
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The present invention relates to a stereoselective glycosylation for the preparation of 1,3-oxathiolane nucleoside in high yield and high optical purity. The invention specifically relates to a process of the preparation of Lamivudine and Emtricitabine using zirconium (IV) chloride (ZrCl4) as a catalyst in glycosylation.
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Page/Page column 17; 18
(2013/03/26)
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- Practical enantioselective synthesis of lamivudine (3TC) via a dynamic kinetic resolution
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A practical enantioselective synthesis of lamivudine 1 is described. A highly effective dynamic kinetic resolution of the 5-hydroxyoxathiolane, followed by chlorination and introduction of cytosine provides an efficient synthesis of lamivudine.
- Goodyear, Michael D.,Hill, Malcolm L.,West, Jono P.,Whitehead, Andrew J.
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p. 8535 - 8538
(2007/10/03)
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