4664-08-8Relevant articles and documents
High-yield synthesis method of methyl 4-aminonicotinate
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Paragraph 0024-0027; 0033-0036; 0042-0045, (2021/09/08)
The invention discloses a high-yield synthesis method of methyl 4-aminonicotinate, which comprises the following steps: by taking 3, 4-dipicolinic acid as a raw material, carrying out intramolecular dehydration substitution, ammonia ammonification, improved NBS Hofmann rearrangement and hydrolysis to obtain the methyl 4-aminonicotinate. The synthesis method disclosed by the invention is simpler to operate, mild in reaction condition and higher in total yield, and has an extremely high application value.
A cedar Joan maleic acid salt preparation method
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Paragraph 0042; 0043; 0044, (2017/08/25)
The invention provides a pixantrone maleate synthesis method which has the advantages of high yield, low impurity content, simple process and easiness in large-scale production. In the method, pyridine-3,4-dicarboxylic acid is used as a starting raw material which reacts with acetic anhydride to obtain pyridine-3,4-dicarboxylic anhydride; the pyridine-3,4-dicarboxylic anhydride conducts an Friedel-Crafts acylation reaction with 1,4-difluorobenzene, and the obtained mixture is subjected to catalytic cyclization to obtain a key intermediate; the intermediate reacts with amino-protected ethylenediamine to obtain protecting group-containing pixantrone; and after that, deprotection and salifying are performed to obtain the target product. In the Friedel-Crafts acylation reaction of the method, an n-hexane solution of sulfuric acid is used as a catalyst, thus the use is convenient, the aftertreatment is simple, and the potential risk in production is eliminated; the Cbz or Fmoc protected ethylenediamine reacts with substituted anthraquinone and then the protecting group is removed through catalytic hydrogenation to obtain pixantrone; the process effectively inhibits side reactions and reduces the impurity content; and meanwhile, the aftertreatment is simplified, and the yield increase is facilitated.
PYRIDAZINE DERIVATIVES AS HEDGEHOG PATHWAY INHIBITORS
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Paragraph 00183, (2015/01/16)
This invention relates to novel compounds. The compounds of the invention are hedgehog pathway agonists. Specifically, the compounds of the invention are useful as Smoothened (SMO) agonists. The invention also contemplates the use of the compounds for treating conditions treatable by the inhibition of the Hedgehog pathway and SMO, for example cancer.
