- Preparation method of 2-n-propoxy acetyl chloride
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The invention relates to the field of chemical synthesis of 2-n-propoxy acetyl chloride, and discloses a preparation method of 2-n-propoxy acetyl chloride. The preparation method comprises the following steps: (1) reacting sodium chloroacetate with alkali in an n-propyl alcohol solvent to obtain a mixture containing a component shown by formula (I); (2) distilling the mixture to obtain a product from which part of n-propyl alcohol is removed; (3) adding water into the obtained product and distilling the product to replace residual n-propyl alcohol in the product, so as to obtain a product containing water and the component shown by formula (I); (4a) adding acid to the product obtained in step (3), extracting the product with a water-insoluble solvent, and reacting the product with an acylating agent to obtain 2-n-propoxy acetyl chloride shown in formula (III); or, (4B) reacting the product obtained in step (3) with an acylating reagent to obtain 2-n-propoxy acetyl chloride shown in formula (III), wherein formula (I), formula (II) and formula (III) are as described in the specification. The method provided by the invention has mild reaction conditions, less solvent consumption, highproduct yield and less byproducts.
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Paragraph 0051; 0057-0059; 0080-0082; 0103-0104; 0116-0117
(2019/03/23)
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- Optimization of 2-alkoxyacetates as acylating agent for enzymatic kinetic resolution of chiral amines
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In this study, the activity of acetic acid esters modified with electron withdrawing 2-alkoxy-groups was investigated as acylating agent in kinetic resolution (KR) of racemic amines. A homologous series of the isopropyl esters of four 2-alkoxyacetic acids (2-methoxy-, 2-ethoxy-, 2-propoxy- and 2-butoxyacetic acids) were prepared and investigated for enantiomer selective N-acylation, catalyzed by lipase B from Candida antarctica, under batch and continuous-flow conditions. In the first set of experiments, isopropyl 2-propoxyacetate showed the highest effectivity with all of the four racemic amines [(±)-1-phenylethylamine, (±)-4-phenylbutan-2-amine, (±)-heptan-2-amine and (±)-1-methoxypropane-2-amine] in the set enabling excellent conversions (≥46%) and enantiomeric excess values (ee ≥ 99%) with each amines in continuous-flow mode KRs under the optimized reaction conditions. In a second set of experiments, KRs of five additional amines – being substituted derivatives of (±)-1-phenylethylamine – further demonstrated the usefulness of isopropyl 2-propoxyacetate – being the best acylating agent in the first set of KRs – in KRs leading to (R)-N-propoxyacetamides with high ee values (≥99.8%).
- Oláh, Márk,Kovács, Dániel,Katona, Gabriel,Hornyánszky, Gábor,Poppe, László
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p. 3663 - 3670
(2018/06/04)
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- PYRIDINE [2,3-B] PYRAZINONES
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Compounds of Formula (I), wherein R2, Y6, R6A, R6, and R8 are as defined in the specification. Corresponding pharmaceutical compositions, methods of treatment, synthetic methods, and intermediates are also disclosed.
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Page/Page column 59
(2010/11/25)
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- Preparation of naphthoquinone derivatives from plumbagin and their ichthyotoxicity
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Various naphthoquinone derivatives were prepared from a natural product, 5-hydroxy-2-methyl-1,4-naphthoquinone (plumbagin); these were mostly substituted at C-3 through carbon-carbon bond formation mediated by a metal- based oxidant such as lead tetraacetate in the presence of various carboxylic acids. The halogenated compounds showed stronger ichthyotoxicity than plumbagin, but other derivatives were less active.
- Ogihara, Kazuhito,Yamashiro, Rieko,Higa, Matsutake,Yogi, Seiichi
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p. 437 - 445
(2007/10/03)
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