- A novel approach to the synthesis of 5-trifluoromethyl-3-substituted pyrazoles
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The 3-cyano-4-trifluoromethyl-6-phenyl or substituted phenyl 2(1H) pyridones (1) on reaction with hydrazine hydrate, gave exclusively in 5-trifluoromethyl-3-substituted pyrazoles (3) through a novel method. A possible mechanistic pathway for change in the
- Krishnaiah,Narsaiah
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- Facile synthesis of α-functionalized vinyl sulfides bearing β-trifluoromethyl group: a highly potential CF3-containing building blocks
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The β-(trifluoromethyl)vinylsulfides on treatment with n-BuLi/TMEDA were readily lithiated at α-position of the sulfanyl group, and the generated α-lithiovinylsulfides were trapped with a variety of electrophiles to give the corresponding β-trifluoromethy
- Hanamoto, Takeshi,Anno, Ryoko,Yamada, Kenji,Ryu, Kousuke
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p. 3727 - 3730
(2008/02/09)
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- Haloacetylated enol ethers 10. Condensation of β-alkoxyvinyl trifluoromethyl ketones with thiosemicarbazide. Synthesis of new trifluoromethyl 4,5-dihydro-1H-1-pyrazolethiocarboxyamides
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The synthesis of 3-aryl[alkyl]-5-hydroxy-5-trifluoromethyl-4,5-dihydro-1H-1- pyrazolethiocarboxyamides (2a-g) from the direct cyclo-condensation reaction of β-alkoxyvinyl trifluoromethyl ketones (1a-g) with thiosemicarbazide in methanol, under mild conditions, is reported. Similarly, the 1H-1-pyrazolethiocarboxyamide derivatives (2a-g) were easily dehydrated and the thiocarboxyamide group hydrolyzed in a one-step reaction by stirring with concentrated sulfuric acid to give the 3-aryl[alkyl]-5-trifluoromethyl-1H-pyrazoles (3a-g) in good yields. Specific syntheses and physical properties of 3-aryl[alkyl]-5-hydroxy-5-trifluoromethyl-4,5-dihydro-1H-1- pyrazolethiocarboxyamides are reported here for the first time.
- Bonacorso,Wastowski,Zanatta,Martins,Naue
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