Related Products of 112758-40-4, As we all know, there are many different methods for the synthesis of a compound, and people can choose the synthesis method that suits their own laboratory according to the actual situation. 112758-40-4 name is 3-Methyl-1H-pyrazole-4-carbaldehyde, This compound is widely used in many fields, so it is necessary to find a new synthetic route. The downstream synthesis method of this compound is introduced below.
To a solution of 3 -methyl- lH-pyrazole-4-carbaldehyde (1 g, 9.08 mmol) in acetonitrile (10 mL) is added potassium carbonate (1.76 g, 12.71 mmol) and 2,3- difluornitrobenzene (1.73 g, 10.90 mmol) and the mixture is stirred at room temperature overnight. Water is added and the organic phase is extracted with ethyl acetate. Organic layer is dried over sodium sulfate and the solvent evaporated under reduced pressure. The residue is purified by normal phase Isco chromatography using as eluent ethyl acetate/hexane (20-80%) to give a 62% yield of a mixture of regioisomers containing the title compound as major product that is used with no further purification. NMR is consistent with desired structure, although mixture of regiosomers is detected: NMR (MeOD): 9.98 (s, 1H), 8.65 (d, 1H, J= 1.6 Hz), 7.99-7.26 (m, 3H), 2.49 (s, 3H). A solution of 2-chloro-4,4-difluoro-spiro[5H-thieno[2,3-c]pyran-7,4′-piperidine] (2.1 g, 7.5 mmol) and l-(2-fluoro-6-nitro-phenyl)-3-methyl-pyrazole-4-carbaldehyde (3 g) (as major compound in a mixture of regioisomers in the pyrazole) in dichloromethane (47 mL) is stirred at room temperature for 30 minutes. Then, sodium triacetoxy borohydride (3.94g) is added and the mixture is stirred overnight at that temperature. The reaction mixture is quenched carefully with sodium bicarbonate (saturated solution) and extracted with dichloromethane. Organic layer is washed with brine, decanted and dried over sodium sulfate. Solvent is evaporated and the residue is purified by normal phase Isco chromatography using as eluant dichloromethane and isopropanol to give 2.28 g of 2-chloro-4,4-difluoro- -[[l-(2-fluoro-6-nitro-phenyl)-3-methyl-pyrazol-4- yl]methyl]spiro[5H-thieno[2,3-c]pyran-7,4′-piperidine] (the compound is contaminated with the other pyrazole regioisomer in a ratio 80:20). MS (m/z): 513 (M+l).
At the same time, in my other blogs, there are other synthetic methods of this type of compound, 3-Methyl-1H-pyrazole-4-carbaldehyde, and friends who are interested can also refer to it.