Carbon tetrabromide → 5-Bromo-1-methyl-2-(2-methyl-imidazol-1-ylmethyl)-1H-imidazole

Temperature

0 °C

(5-Bromo-1-methyl-1H-imidazol-2-yl)-methanol (1.0 g, 5.24 mmol) and tetrabromomethane (2.48 g, 7.33 mmol) were dissolved in THF (10.0 ml) and cooled to 0° C. Triphenylphosphine (1.98 g, 7.33 mmol) was added portionwise over a period of 30 min. The reaction mixture was stirred at 0° C. for 1 h to provide a white suspension. In a second flask, NaH (1.05 g, 26.18 mmol, 60% in mineral oil) was suspended in DMF (20 ml) and cooled to 0° C. 2-Methylimidazole (2.15 g, 26.2 mmol) was added portionwise. The reaction mixture was stirred at 60° C. for 30 min, cooled to 0° C. and treated with the above suspension. After 2 h stirring at room temperature, the reaction mixture was quenched with aqueous saturated NaHCO3 solution (50 ml). The aqueous layer was extracted 3 times with AcOEt. The combined extracts were dried over Na2SO4, filtered and the solvent was removed in vacuo. The residue was chromatographed (silica, elution with CH2Cl2/MeOH=95:5) to provide the title compound (0.7 g, 52%) as a brown solid. MS: m/e=255.0 (M+).

1. customto provide a white suspension
2. temperaturecooled to 0° C
3. stirringThe reaction mixture was stirred at 60° C. for 30 min
4. temperaturecooled to 0° C.
5. additiontreated with the above suspension
6. stirringAfter 2 h stirring at room temperature
7. customthe reaction mixture was quenched with aqueous saturated NaHCO3 solution (50 ml)
8. extractionThe aqueous layer was extracted 3 times with AcOEt
9. dry with materialThe combined extracts were dried over Na2SO4
10. filtrationfiltered
11. customthe solvent was removed in vacuo
12. customThe residue was chromatographed
13. wash(silica, elution with CH2Cl2/MeOH=95:5)

ORD record

ord-b81182f43c524e5fa58830cdae39ad78

Source dataset

uspto-grants-2003_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06610723B2