![](/CAS/GIF/122431-37-2.gif)
1-Methyl-3-(trifluoromethyl)-1H-pyrazol-5-ol synthesis
- Product Name:1-Methyl-3-(trifluoromethyl)-1H-pyrazol-5-ol
- CAS Number:122431-37-2
- Molecular formula:C5H5F3N2O
- Molecular Weight:166.1
![Pentanoic acid, 5-fluoro-4,4-bis(fluoromethyl)-3-oxo-, ethyl ester](/CAS/20210111/GIF/944546-18-3.gif)
944546-18-3
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![Methylhydrazine](/CAS/GIF/60-34-4.gif)
60-34-4
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$65.59/25g
![1-Methyl-3-(trifluoromethyl)-1H-pyrazol-5-ol](/CAS/GIF/122431-37-2.gif)
122431-37-2
144 suppliers
$12.00/250mg
Yield:122431-37-2 97%
Reaction Conditions:
Stage #1: ethyl-4,4,4-trifluoromethylacetoacetate;methylhydrazine in ethanol at 20 - 80; for 15 h;
Stage #2: with sodium hydroxide in ethanol at 20; for 1 h;
Steps:
3.1
Preparation of compound 3a: l-Methyl-3-trifluoromethyl-lH-pyrazol-5-ol. Methylhydrazine (3.42 mL, 65.1 mmol) was added all at once to a stirred solution of ethyl 4,4,4- trifluoromethylacetoacetate (9.53 mL, 65.1 mmol) and ethanol (261 mL) at rt under nitrogen. The reaction mixture was heated to 80 0C for 15 h then cooled to rt. NaOH (5.22 g) was added all at once and the mixture stirred for 1 h at rt. The reaction mixture was concentrated under vacuum, diluted with ethyl acetate (2 x 300 mL) and washed with IM HCl (300 mL). The combined organics were dried over MgSO4, filtered and concentrated to afford 10.5 g (97%) of l-methyl-3-trifluoromethyl-lH-pyrazol-5-ol as a yellow solid
References:
WO2007/84868,2007,A2 Location in patent:Page/Page column 26
![Ethyl 4,4,4-trifluoroacetoacetate](/CAS/GIF/372-31-6.gif)
372-31-6
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$5.00/10g
![Methylhydrazine](/CAS/GIF/60-34-4.gif)
60-34-4
2 suppliers
$65.59/25g
![1-Methyl-3-(trifluoromethyl)-1H-pyrazol-5-ol](/CAS/GIF/122431-37-2.gif)
122431-37-2
144 suppliers
$12.00/250mg
![Methylhydrazine sulfate](/CAS/GIF/302-15-8.gif)
302-15-8
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![Ethyl 4,4,4-trifluoroacetoacetate](/CAS/GIF/372-31-6.gif)
372-31-6
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$5.00/10g
![1-Methyl-3-(trifluoromethyl)-1H-pyrazol-5-ol](/CAS/GIF/122431-37-2.gif)
122431-37-2
144 suppliers
$12.00/250mg
![Ethyl 4,4,4-trifluoroacetoacetate](/CAS/GIF/372-31-6.gif)
372-31-6
470 suppliers
$5.00/10g
![1-Methyl-3-(trifluoromethyl)-1H-pyrazol-5-ol](/CAS/GIF/122431-37-2.gif)
122431-37-2
144 suppliers
$12.00/250mg