1968-51-0Relevant articles and documents
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Stodola et al.
, p. 2290,2292 (1951)
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Method for preparing 2-hydroxymethyl-3-alkoxy-4H-pyran-4-one by one-pot process
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Paragraph 0015, (2020/09/12)
The invention relates to a method for preparing 2-hydroxymethyl-3-alkoxy-4H-pyran-4-one by a one-pot process. The method is characterized by comprising the following steps: (1) dissolving pyromeconicacid with the concentration of 0.1-5 mol/L in a solvent, adding an alkali, controlling the molar ratio of pyromeconic acid to the alkali to be 1:(0.5-5), adding a formaldehyde aqueous solution with the weight percentage content of 20-50%, controlling the molar ratio of formaldehyde to pyromeconic acid to be (1-3):1, and reacting for 1-24 hours at the temperature of 0-100 DEG C; and (2) directly adding an alkylation reagent into step (1), controlling the molar ratio of the alkylation reagent to pyromeconic acid to be (1-3):1, and reacting at 10-100 DEG C for 1-24 hours. The method has the following advantages: on the basis of ensuring the reaction yield and the product quality, the separation of an intermediate is omitted, the operation steps are reduced, and the production period is shortened; and consumption of solvents and acid-base materials is reduced, and production cost is saved.
Synthesis method of 3-(benzyloxy)-4-oxo-4H-pyran-2-carboxylic acid
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Paragraph 0024; 0025; 0028; 0029; 0032; 0033; 0036; 0037, (2019/04/02)
The invention discloses a synthesis method of 3-(benzyloxy)-4-oxo-4H-pyran-2-carboxylic acid. The synthesis method takes furfuryl alcohol as a starting raw material and four-step reaction including rearrangement, addition, hydroxyl protection and oxidization is carried out; the total mol yield of a synthesis route is greater than 32 percent; the synthesis method has the characteristics of relatively moderate reaction conditions and the like, and the yield and purity of the 3-(benzyloxy)-4-oxo-4H-pyran-2-carboxylic acid are remarkably improved; meanwhile, the synthesis method has the advantagesof detailed technological operation steps, specific parameters, controllable conditions and stable technology, and can realize industrial large-batch production.
Orally active iron (III) chelators
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Page column 9, (2008/06/13)
A novel 3-hydroxypyridin-4-one compound of formula I is provided wherein R is hydrogen or a group that is removed by metabolism in vivo to provide the free hydroxy compound, R1 is an aliphatic hydrocarbon group or an aliphatic hydrocarbon group substituted by a hydroxy group or a carboxylic acid ester, sulpho acid ester or a C1-6 alkoxy, C6-aryloxy or C7-10aralkoxy ether thereof, R3 is selected from hydrogen and C1-6alkyl; and R4 is selected from hydrogen, C1-6alkyl and a group as described for R2; characterised in that R2 is selected from groups —CONH—R5??(i) —CH2NHCO—R5??(ii) —SO2NH—R5??(iii) —CH2NHSO2—R5??(iv) —CR6R6OR7??(v) —CONHCOR5??(viii) ?wherein R5 is selected from hydrogen and optionally hydroxy, alkoxy, or aralkoxy substituted C1-13 alkyl, aryl and C71-13 aralkyl, R6 is independently selected from hydrogen, C1-13 alkyl, aryl and C7-13 aralkyl, and R7 is selected from hydrogen, C1-13 alkyl, aryl and C7-13 aralkyl or a pharmaceutically acceptable salt of any such compound with the proviso that when R7 is hydrogen, R6 is not selected from aryl and with the proviso that the compound is not 1-ethyl-2-(1′-hydroxyethyl)-3-hydroxypyridin-4-one.