ChemicalBook CAS DataBase List 3-Methyl-2-pyrazolin-5-one

3-Methyl-2-pyrazolin-5-one synthesis

5synthesis methods

Product Name:3-Methyl-2-pyrazolin-5-one
CAS Number:108-26-9
Molecular formula:C4H6N2O
Molecular Weight:98.1

105-45-3
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$5.00/5g

108-26-9
245 suppliers
$5.00/10g

Yield:108-26-9 97.3%

Reaction Conditions:

with hydrazine hydrate in methanol at 50; for 3 h;Inert atmosphere;Temperature;

Steps:

1 Example 5
(1) 96.5 ml of methanol and 92.8 g of methyl acetoacetate (0.8 mol) were added to the reaction apparatus, and the mixture was stirred.Methanol and methyl acetoacetate are well mixed and heated to 50 ° C; (2) Firstly, nitrogen gas is introduced into the reaction device for 10 to 30 minutes, and then 40.4 g of hydrazine hydrate (0.808 mol) is added dropwise.The addition time is controlled at 15 min. After the addition is completed, the nitrogen gas is continuously passed for 5 to 15 minutes, and the temperature is further increased to reflux, and the heat preservation reaction is carried out for 3 hours; (3) After the reaction is completed, the temperature is lowered to 5 to 10 ° C, and the time for cooling is controlled at 55 to 60 minutes to precipitate the product.The filter cake was collected by suction filtration, and the filter cake was washed twice with ice methanol and then dried to obtain 3-methyl-5-pyrazolone solid.The resulting 3-methyl-5-pyrazolone is a white crystal.The melting point of the test was 220 to 222 ° C, which was consistent with the literature values.The results of mass spectrometry detection are consistent with the theoretical simulation results, as shown in Figure 1. The infrared spectrum is consistent with the standard spectrum in the infrared spectrum library, as shown in Figure 2. The purity of 3-methyl-5-pyrazolone (high performance liquid chromatography) was 99.9%, and the yield was 97.3%.

References:

Tsingtao Bay Fine Chemical Co., Ltd.;Tsingtao Bay Group Co., Ltd.;Chen Anyuan;Ma Zaihe;Sun Shanqi;Gao Chao;Li Guangshun;Xia Hongkun;Teng Hui CN108218778, 2018, A Location in patent:Paragraph 0042-0083

FullText

141-97-9 Synthesis