25016-11-9, 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. 25016-11-9 name is 1-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.
A mixture of intermediate 10b (200 mg), 1-methyl-i H-pyrazole-4-carboxaldehyde (183 mg; 1.66 mmol) and AcOH (32 jiL; 0.555 mmol) in DCE (6 mL) was stirred at 50Cfor 2 hours. The reaction mixture was cooled to room temperature and NaBH(OAc)3 (353 mg; 1.665 mmol) was added. The reaction mixture was stirred at room temperature overnight, poured onto a 10% aqueous solution of K2C03 and extracted with DCM. The organic layer was decanted, dried over MgSO4, filtered and evaporated to dryness. The residue was purifed by chromatography over silica gel (irregular SiOH,24g; mobile phase: gradient from 0% NH4OH, 0% MeOH, 100% DCM to 1% NH4OH,10% MeOH, 90% DCM). The pure fractions were collected and evaporated to dryness yielding 165 mg of compound 28 as an oil (73%). Compound 28 was dissolved in ACN and HC1 (4N in dioxane) (277 jiL; 1.11 mmol) was added. The HC1 salt was filtered but revealed to be too hydroscopic. The residue was then dissolved inDCM/MeOH and the organic layer was washed with a 10% aqueous solution of K2C03, dried over MgSO4, filtered and evaporated to dryness. The resulting residue was dissolved in ACN and fumaric acid (47 mg; 0.404 mmol; 1 eq) was added and the solution was allowed to stand until crystallization (overnight). The precipitate was filtered, washed with ACN then Et20 and dried yielding 188 mg of compound 28 as thefumarate salt (1 equivalent based on 1H NMR).
At the same time, in my other blogs, there are other synthetic methods of this type of compound, 1-Methyl-1H-pyrazole-4-carbaldehyde, and friends who are interested can also refer to it.