1-Methyl-1H-pyrazol-3(2H)-one synthesis
- Product Name:1-Methyl-1H-pyrazol-3(2H)-one
- CAS Number:52867-35-3
- Molecular formula:C4H6N2O
- Molecular Weight:98.1
5788-17-0
52867-35-3
Example 7: General procedure for the synthesis of 1-methyl-1H-pyrazol-3(2H)-one from methyl 3-methoxyacrylate and monomethylhydrazine. In a 250 mL flask, 70 g of methanol and 60.5 g (0.46 mol) of 35% concentration of monomethylhydrazine aqueous solution were first added and the reaction temperature was kept at 25 °C. Subsequently, 47.8 g (0.40 mol) of methyl 3-methoxyacrylate was slowly added dropwise over 25 min. The pH of the reaction mixture was maintained at 12 by parallel dropwise addition of a 17% concentration of aqueous NaOH solution during the dropwise addition and during subsequent stirring for 6 h. A total of 97.5 g of NaOH solution was consumed for this process. The yield of the target product 1-methyl-1H-pyrazol-3(2H)-one was 75% when the reaction reached 100% conversion. The ratio of 3-hydroxy isomer to 5-hydroxy isomer in the product was ≥15:1.
5788-17-0
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$21.00/5mL
52867-35-3
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$14.00/250mg
Yield:52867-35-3 75%
Reaction Conditions:
with sodium hydroxide in methanol;
Steps:
7 3-Hydroxy-1-methylpyrazole from Methyl 3-methoxyacrylate and Monomethylhydrazine (35%)
Example 7 3-Hydroxy-1-methylpyrazole from Methyl 3-methoxyacrylate and Monomethylhydrazine (35%) In a 250 ml flask, 70 g of methanol and 60.5 g (0.46 mol) of 35% strength aqueous monomethylhydrazine are initially charged at 25° C. At the same temperature, 47.8 g (0.40 mol) of methyl 3-methoxyacrylate are metered in over a period of 25 min. By parallel addition of 17% strength aqueous NaOH solution, the pH of the reaction mixture during the metered addition of the methyl methoxyacrylate and during the extra stirring time (6 hours) is maintained at 12. Over this period of time, 97.5 g of NaOH solution are consumed. The yield is 75% at 100% conversion. Isomer ratio: (3-hydroxy isomer:5-hydroxy isomer)>=15:1
References:
US6392058,2002,B1
29184-71-2
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52867-35-3
90 suppliers
$14.00/250mg