5-Bromo-1-methyl-1H-imidazole → Bis(1-methyl-1H-imidazol-5-yl)methanone

To a solution of 5-bromo-1-methyl-1H-imidazole (1.2 g, 7.45 mmol) in DCM (10 mL) was added ethyl magnesium bromide (2.5 mL, 7.45 mmol, 3.0 M in diethyl ether) dropwise over a 10 minute period. The resulting pale yellow solution was stirred at room temperature for 15 minutes, cooled in an ice bath to 0° C. and then N-methoxy-N,1-dimethyl-1H-imidazole-5-carboxamide (1.0 g, 6.21 mmol, Intermediate 55: step a) dissolved in DCM (3 mL) was added dropwise. The cold bath was removed and the reaction mixture stirred at room temperature for 48 hours. To the resulting yellow suspension was added water followed by 6 M aqueous HCl to a neutral pH (pH=6-7). The aqueous mixture was extracted with DCM (2×). The combined DCM extracts were dried over MgSO4, filtered and concentrated under reduced pressure. The product was precipitated with Et2O, filtered and dried to provide the title compound as a tan solid.

1. temperaturecooled in an ice bath to 0° C.
2. additionwas added dropwise
3. customThe cold bath was removed
4. stirringthe reaction mixture stirred at room temperature for 48 hours
5. additionTo the resulting yellow suspension was added water
6. extractionThe aqueous mixture was extracted with DCM (2×)
7. dry with materialThe combined DCM extracts were dried over MgSO4
8. filtrationfiltered
9. concentrationconcentrated under reduced pressure
10. customThe product was precipitated with Et2O
11. filtrationfiltered
12. customdried

ORD record

ord-822c403e578b4d17abc79df5c29a8b11

Source dataset

uspto-grants-2016_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09284308B2