219986-56-8Relevant articles and documents
Haloacetylated enol ethers 10. Condensation of β-alkoxyvinyl trifluoromethyl ketones with thiosemicarbazide. Synthesis of new trifluoromethyl 4,5-dihydro-1H-1-pyrazolethiocarboxyamides
Bonacorso,Wastowski,Zanatta,Martins,Naue
, p. 23 - 26 (2007/10/03)
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.
