In the chemical reaction process, reaction time, type of solvent, can easily affect the result of the reaction, thereby determining the yield and properties of the reaction product. An updated downstream synthesis route of 151049-87-5 as follows. Quality Control of 3-Bromo-1-methyl-1H-pyrazole
To a solution of 3-bromo-1-methyl-1H-pyrazole (40 g, 248 mmol) (see the Supporting Information for the synthesis) in THF (1 L) was added dropwise a solution of t-BuLi (200 mL, 1.3 M, 260 mmol) in hexane at -90 C under N2 with stirring over 2 h. The reaction mixture was stirred at -90 C for further 0.5 h. Then a solution of (SS)-4 (58 g, 209 mmol) in THF (0.2 L) was added dropwise to the reaction mixture at -90 C. The mixture was stirred and warmed slowly to r.t. overnight. TLC showed the desired spot with Rf = 0.25 (EtOAc). Then the solution was quenched with sat. aq NH4Cl (1 L) and extracted with Et2O (3 ¡Á 0.8 L). The combined organic layers were dried (Na2SO4) concentrated. The crude product was purified by column chromatography over silica gel (PE-EtOAc, 20:1 ? 2:1) to give the title product; yield: 22.9 g (30%); brown oil; Rf = 0.25 (EtOAc).
According to the analysis of related databases, 151049-87-5, the application of this compound in the production field has become more and more popular.