4-Fluoro-1H-pyrazole synthesis
- Product Name:4-Fluoro-1H-pyrazole
- CAS Number:35277-02-2
- Molecular formula:C3H3FN2
- Molecular Weight:86.07
761-88-6
35277-02-2
General procedure for the synthesis of 4-fluoro-1H-pyrazole using the compound (CAS: 761-88-6) as starting material: dihydrazine (4.48 g, 0.043 mol) was added to (Z)-3-(dimethylamino)-2-fluoroacrylaldehyde (5 g, 0.043 mol) in 100 mL of 40% (V/V) aqueous ethanol solution. Subsequently, the reaction mixture was heated at 55 °C for 30 min. After completion of the reaction, the mixture was cooled to room temperature and the pH was adjusted with saturated aqueous sodium bicarbonate to 9. The aqueous layer was extracted with ether and the organic layers were combined and dried with anhydrous sodium sulfate. Finally, the solvent was removed by distillation under reduced pressure to give 3.6 g of the title compound 28-d as a yellow oil in 77% yield.
761-88-6
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35277-02-2
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Yield:35277-02-2 77%
Reaction Conditions:
with hydrazine dihydrochloride in ethanol;water at 55; for 0.5 h;
Steps:
28.C Step C: 4-fluoro-1H-pyrazole (28-d)
Hydrazine dihydro chloride (4.48g, 0.043mol) was added to a solution of (Z)-3- (dimethylamino)-2-fluoroacrylaldehyde, 28-c, (5g, 0.043mol) in 100 mL of 40%>V/V solution of EtOH in water, then the mixture was heated at 55 °C for 30 minutes. The reaction was cooled to room temperature, basified to pH=9 with a saturated solution of NaHCC"3 and the aqueous layer was extracted with Et20. The organic layers were combined and dried with Na2SC"4, the solvent was removed to give 3.6 g of the titled product, 28-d, as a yellow oil (77%)
References:
MERCK SHARP & DOHME CORP.;ZHOU, Changyou;ZOU, Wuxin;HUA, Yuxia;DANG, Qun WO2013/40790, 2013, A1 Location in patent:Page/Page column 87; 88
139680-79-8
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35277-02-2
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853180-40-2
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35277-02-2
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38346-22-4
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35277-02-2
194 suppliers
$8.00/100mg
761-88-6
1 suppliers
inquiry
35277-02-2
194 suppliers
$8.00/100mg