The important role of 5-Bromo-1-methyl-1H-imidazole

The basis of chemical reaction formula synthesis, the synthesis route is composed of some specific reactions and combined according to certain logical thinking. We look forward to the emergence of more reaction modes in the future.

Electric Literature of 1003-21-0, A common heterocyclic compound, 1003-21-0, name is 5-Bromo-1-methyl-1H-imidazole, molecular formula is C4H5BrN2, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route.

Ethyl magnesium bromide (3.0 M in diethyl ether, 21.5 mL, 64.4 mmol) was added via syringe over a few minutes to a clear colorless solution of 5-bromo-1-methyl-1H-imidazole (10.4 g, 64.4 mmol) in THF (100 mL) under a nitrogen atmosphere in an ice bath. A white precipitate formed during the addition. The mixture was removed from the ice bath and was stirred for 20 minutes, then was again cooled in an ice bath before addition of 4-chloro-N-methoxy-N-methylbenzamide (10.7 g, 53.6 mmol, Intermediate 1: step a). The resulting white suspension was stirred overnight at room temperature. The reaction was quenched by addition of saturated aqueous NH4Cl and diluted with water. The mixture was partially concentrated to remove THF and was diluted with DCM. The mixture was acidified to pH 1 with 1 N aqueous HCl, then neutralized with saturated aqueous NaHCO3. The phases were separated and the aqueous phase was further extracted with DCM. The organic extracts were washed with water, then were dried (Na2SO4), filtered, and concentrated, affording a white solid. The crude product was triturated with a mixture of EtOAc:heptanes (1:1, 150 mL). The precipitated solid was collected by vacuum filtration, washing with heptanes, to afford the title compound.

The basis of chemical reaction formula synthesis, the synthesis route is composed of some specific reactions and combined according to certain logical thinking. We look forward to the emergence of more reaction modes in the future.

Reference:
Patent; Janssen Pharmaceutica NV; Leonard, Kristi A.; Barbay, Kent; Edwards, James P.; Kreutter, Kevin D.; Kummer, David A.; Maharoof, Umar; Nishimura, Rachel; Urbanski, Maud; Venkatesan, Hariharan; Wang, Aihua; Wolin, Ronald L.; Woods, Craig R.; Pierce, Joan; Goldberg, Steven; Fourie, Anne; Xue, Xiaohua; US2014/107094; (2014); A1;,
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem