875-35-4Relevant articles and documents
Preparation method for nitrobenzisothiazole-pyridine dye with good acid-base stability
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Paragraph 0028-0029; 0037-0039; 0046-0047, (2020/06/02)
The invention discloses a preparation method for a nitrobenzisothiazole-pyridine dye with good acid-base stability. The preparation method comprises the following steps: (1) preparing a compound (i) from 1,4-dimethyl-3-cyano-6-hydroxy-2-pyridone and phosphorus oxychloride; (2) preparing a compound (ii) from the compound (i) and NH2-(CH2)n-O-CH3; (3) preparing a compound (A) from the compound (ii)and NH2-(CH2)n-O-CH3; (4) diazotizing 3-amino-5-nitrobenzoisothiazole by using sodium nitrite so as to obtain diazonium salt; (5) mixing the diazonium salt with the compound (A) for a reaction, and carrying out aging so as to obtain a crude product; and (6) dissolving the crude product, carrying out cooling extraction, and carrying out purifying so as to obtain a compound as shown in a structuralformula (B) which is described in the specification. According to the invention, the nitrobenzisothiazole-pyridine dye with good acid-base stability is synthesized in a functional group conversion mode; and the preparation method provided by the invention is easily-controllable in reaction conditions, simple in operation and high in product yield.
The Guareschi-Thorpe Cyclization Revisited - An Efficient Synthesis of Substituted 2,6-Dihydroxypyridines and 2,6-Dichloropyridines
Eriksson, Magnus C.,Zeng, Xingzhong,Xu, Jinghua,Reeves, Diana C.,Busacca, Carl A.,Farina, Vittorio,Senanayake, Chris H.
, p. 1455 - 1460 (2018/05/16)
DBU as base is key in a practical modified Guareschi-Thorpe cyclization of β-keto esters and 2-cyanoacetamide to allow the synthesis of substituted pyridones in good to excellent yields. The chlorination of DBU salts of pyridones with POCl 3 in the presence of a quaternary ammonium salt under standard atmospheric reflux conditions as opposed to the typical pressure equipment led to high yields of substituted 2,6-dichloropyridines.
Wnt SIGNALING INHIBITOR, COMPOSITION, AND COMPOUND AS USE THEREFOR
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Paragraph 0079; 0080, (2017/08/15)
PROBLEM TO BE SOLVED: To provide an inhibitor for Wnt signaling route. SOLUTION: The present invention provides a compound represented by formula I, and a composition comprising the compound (X1-X8 independently represent CR4 or N; Y1 is H or C (R4)3; Y2 and Y3 independently represent H, halogen or C (R3)3; R1 and R2 independently represent H, halogen, C1-6 alkyl, quinolinyl or the like; R3s independently represent H, halogen, cyano, C1-6 alkyl or the like; R4s independently represent H, halogen, cyano, C1-6 alkoxy or the like). SELECTED DRAWING: None COPYRIGHT: (C)2017,JPOandINPIT