Researchers who often do experiments know that organic synthesis is a process of preparing more complex target molecules from simple raw materials through one or more chemical reactions. Generally, it requires fewer steps, and cheap raw materials. 52867-42-2, name is Methyl 2-methyl-5-oxo-2,5-dihydro-1H-pyrazole-3-carboxylate, A new synthetic method of this compound is introduced below., Recommanded Product: Methyl 2-methyl-5-oxo-2,5-dihydro-1H-pyrazole-3-carboxylate
c) 5-[3-Butyl-5-(l,2-dihydroxy-2-phenyl-ethyl)-isoxazol-4-ylmethoxy]-2-methyl-2H-pyrazole-3- carboxylic acid methyl esterTo a stirred solution of 5-hydroxy-2H-pyrazole-3-carboxylic acid methyl ester (937 mg, 6.0 mmol) and [3-butyl-5-([E]-styryl)-isoxazol-4-yl]-methanol (1.54 g, 6.0 mmol) in THF (120 mL) at 5 0C under argon was added triphenylphosphine (2.1 g, 7.8 mmol), then diethyl azodicarboxylate (1.06 g, 6.0 mmol) was added dropwise. The reaction mixture was warmed to room temperature overnight. The reaction mixture was then poured into aqueous sodium chloride (saturated) and the mixture was extracted with ethyl acetate. The combined organic layers were then washed with water and saturated sodium hydrogen carbonate solution and then dried over sodium sulfate, filtered and evaporated. Concentration and purification by chromatography (silica, heptane:ethyl acetate = 4:1 to 7:3) afforded the intermediate product (1.07 g, 45%) as a yellow oil. MS: m/e = 396.2 [M+H]+. To a solution of the intermediate product (0.79 g, 2.0 mmol) in tert-butanol (50 mL) was added AD Mix-alpha (2.8 g) with water (50 mL). The reaction mixture was stirred at room temperature overnight and extracted with ethyl acetate. The combined organic phases were washed with brine, dried over sodium sulfate and concentrated to a yellow oil. The crude material was purified by flash chromatography (silica gel, heptane:ethyl acetate 7:3 to 1 :1) to afford the title compound (440 mg, 51%) as a colorless oil. MS: m/e = 430.2 [M+H]+.
The synthetic route of 52867-42-2 has been constantly updated, and we look forward to future research findings.
Reference:
Patent; F. HOFFMANN-LA ROCHE AG; JAKOB-ROETNE, Roland; LUCAS, Matthew, C.; THOMAS, Andrew; WO2010/127975; (2010); A1;,
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