- Preparation method of parecoxib sodium intermediate 5-methyl-3,4-diphenyl isoxazole
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The invention relates to a preparation method of parecoxib sodium intermediate 5-methyl-3,4-diphenyl isoxazole. The preparation method comprises the following steps: step one, taking phenyl propinyl ketone as a starting material, firstly, carrying out condensation with methanol aminated hydrochloride to generate Z-type 1-phenyl-1-propinyl-3-methyl-oxime; step two, carrying out a cycloaddition reaction on the Z-type 1-phenyl-1-propinyl-3-methyl-oxime and iodine chloride to generate 3-phenyl-4-iodo-5-methyl isoxazole; and step three, carrying out a substitution reaction on the 3-phenyl-4-iodo-5-methyl isoxazole and phenylboronic acid to generate 5-methyl-3,4-diphenyl isoxazole.
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Paragraph 0032; 0035-0036
(2018/07/06)
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- The synthesis of highly substituted isoxazoles by electrophilic cyclization: An efficient synthesis of valdecoxib
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(Chemical Equation Presented) A large number of functionally substituted 2-alkyn-1-one O-methyl oximes have been cyclized under mild reaction conditions in the presence of ICl to give the corresponding 4-iodoisoxazoles in moderate to excellent yields. The resulting 4-iodoisoxazoles undergo various palladium-catalyzed reactions to yield 3,4,5-trisubstituted isoxazoles, including valdecoxib.
- Waldo, Jesse P.,Larock, Richard C.
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p. 9643 - 9647
(2008/03/17)
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- Synthesis of isoxazoles via electrophilic cyclization
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(Chemical Equation Presented) A variety of 3,5-disubstituted 4-halo(seleno)isoxazoles are readily prepared in good to excellent yields under mild reaction conditions by the reaction of 2-alkyn-1-one O-methyl oximes with ICI, I2, Br2,
- Waldo, Jesse P.,Larock, Richard C.
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p. 5203 - 5205
(2007/10/03)
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