- Preparation method of 3-pyridylacetic acid hydrochloride
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The invention discloses a preparation method of 3-pyridylacetic acid hydrochloride and belongs to the field of chemistry. A 3-pyridylacetic acid hydrochloride product is prepared from 3-methylpyridine chlorination side product 2-chloro-3-methylpyridine as a raw material through cyanidation, alkaline hydrolysis, hydrogenation reduction and salification. The 3-pyridylacetic acid hydrochloride product has purity of 98.5% or more.
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Paragraph 0020; 0023; 0024; 0025; 0028; 0029
(2017/02/28)
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- A 3-pyridine acetic acid hydrochloride method for the preparation of
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The invention belongs to the field of medical intermediates and in particular relates to a preparation method of 3-pyridineacetic acid hydrochloride. According to the preparation method, with 3-acetylpyridine as a raw material, by virtue of a one pot method, two-step reaction and twice aftertreatment which are reported by literatures are shortened to be once aftertreatment, and a recrystallization step is also saved. The preparation method has the advantages of simplified operation steps, high product quality, more green environmental protection and the like.
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Paragraph 0022; 0023
(2017/04/06)
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- Novel Process For Preparing Risedronic Acid
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The present invention relates to a process for preparing risedronic acid comprising the step of combining a 3-pyridyl acetic acid or a salt thereof, phosphorous acid, and a halophosporous compound selected from PCl3, PClS, POCl3, PBr3, POBr3, and PBr5 in the presence of a diluent that is either a bicyclic aliphatic hydrocarbon or a substituted cyclic aliphatic hydrocarbon or a mixture thereof, in combination with a codiluent, that is orthophosphoric acid
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Page/Page column 4
(2010/06/11)
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- NOVEL PROCESS FOR PREPARING RISEDRONIC ACID
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The present invention relates to a process for preparing risedronic acid comprising the step of combining a 3-pyridyl acetic acid or a salt thereof, phosphorous acid, and a halophosporous compound selected from PCl3, PCI5, POCl3, PBr3, POBr3, and PBr5 in the presence of a diluent that is either a bicyclic aliphatic hydrocarbon or a substituted cyclic aliphatic hydrocarbon or a mixture thereof, in combination with a codiluent, that is orthophosphoric acid.
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Page/Page column 15
(2009/05/28)
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- Syntheses and UV/Vis-spectroscopic properties of hydrophilic 2-, 3-, and 4-pyridyl-substituted solvatochromic and halochromic pyridinium N-phenolate betaine dyes as new empirical solvent polarity indicators
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Syntheses and negative solvatochromism of nine new hydrophilic 2-, 3-, and 4-pyridyl-substituted pyridinium N-phenolate betaine dyes 3-11 are described. These were produced in order to obtain zwitterionic dyes better soluble in water and other aqueous media (such as binary water/solvent mixtures, aqueous ionophore solutions) than the rather hydrophobic standard betaine dyes 1 and 2, which have been used to establish an empirical scale of solvent polarity, called the ET(30) scale. Betaine dye 8, in which three of the peripheral phenyl groups of 1 are replaced by two 3-pyridyl rings and one 4-pyridyl ring, proved to be particularly suitable for the determination of ET(30) values in aqueous media. Wiley-VCH Verlag GmbH, 2001.
- Reichardt, Christian,Che, Daqing,Heckenkemper, Guido,Schaefer, Gerhard
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p. 2343 - 2361
(2007/10/03)
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- Oxidative decarbonylation of β-arylpyruvic acids using sodium perborate
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Oxidation of β-aryl- and β-heteroarylpyruvic acids using sodium perborate tetrahydrate (SPB) in aqueous solution at ambient temperature gives the corresponding arylacetic acids in good yield (68-86%). The mild conditions are convenient for the preparation of thermally unstable acids. In particular the method has been applied to the preparation of an unstable 5- nitroimidazol-2-yl ethanoic acid which could not be obtained using other reagents apparently due to enolisation of the pyruvic acid precursor. Attempts to achieve decarbonylation using calcium hypochlorite or SPB in acidic solution lead to the 2 chloromethyl derivatives. The novel 5- nitroimidazol-2-yl ethanoic acid, which was required as a precursor of molecules of biological interest, has been fully characterised and converted to a known amide. Reaction of this acid with Vilsmeier's reagent gave an enamine derivative and not the expected vinamidinium salt. This novel mode of reaction is attributable to intramolecular hydrogen-bonding and favourable conjugation.
- Morrow, Nicholas,Ramsden, Christopher A.,Sargent, Bruce J.,Wallett, Christiaan D.
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p. 9603 - 9612
(2007/10/03)
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