- New preparation method of febuxostat intermediate
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The invention relates to a new preparation method of a febuxostat intermediate. The method includes: taking cheap 4-hydroxybenzaldehyde as an initial raw material, firstly preparing aldoxime from 4-hydroxybenzaldehyde and hydroxylamine hydrochloride, then adding a corresponding thio reagent, and preparing a compound 4-hydroxythiobenzamide (152A1-00) by Beckmann rearrangement reaction; utilizing one-pot process, adopting cheap 4-hydroxybenzaldehyde as an initial raw material, carrying out a series of reactions, and then performing cyclization with 2-halogenated ethyl acetoacetate to obtain ethyl 2-(4-hydroxyphenyl)-4-methyl-5-thiazolecarboxylate or different salt forms (152A2x) thereof; and using isobutyl sulfonate (152H1x) with more easily controllable quality to replace bromo-isobutane soas to prepare ethyl 2-(3-formyl-4-isobutoxyphenyl)-4-methyl-5-thiazolecarboxylate (152A4-00). In conclusion, the method provided by the invention is more beneficial to safe, simple and cost-efficientindustrial scale preparation of the febuxostat intermediate with higher purity.
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Paragraph 0091-0093
(2020/03/06)
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- Enantioselective synthesis of all-carbon quaternary stereogenic centers by catalytic asymmetric conjugate additions of alkyl and aryl aluminum reagents to five-, six-, and seven-membered-ring β-substituted cyclic enones
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(Chemical Equation Presented) Solution to pesky problems: Effective methods for catalytic asymmetric conjugate additions of alkyl and aryl aluminum reagents with unactivated β-substituted cyclopentenones are now available (see scheme). Transformations, pr
- May, Tricia L.,Brown, M. Kevin,Hoveyda, Amir H.
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supporting information; experimental part
p. 7358 - 7362
(2009/04/10)
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