Allyl bromide → Ethyl 2-[2-methyl-4-(trifluoromethyl)-5-vinyl-imidazol-1-yl]pent-4-enoate

Temperature

-78 °C

To a cooled (−78° C.) solution of ethyl 2-[2-methyl-4-(trifluoromethyl)-5-vinyl-imidazol-1-yl]acetate (790 mg, 3.01 mmol) in THF (6 mL) under nitrogen atmosphere was added LDA (2 M, 3 mL, 6.03 mmol) drop wise. After stirring the reaction mixture at −78° C. for 15 min, allyl bromide (521 μL, 6.03 mmol) was added slowly and the reaction mixture was allowed to warm to room temperature and stirred for 2 h. A saturated NH4Cl solution (20 mL) was added to the reaction mixture at 0° C. and the mixture was then extracted with EtOAc (2×100 mL). The combined EtOAc layers were then washed with brine (50 mL), dried (MgSO4), concentrated in vacuo, and purified by flash chromatography (SiO2, 80% EtOAc/hexanes) to obtain ethyl 2-[2-methyl-4-(trifluoromethyl)-5-vinyl-imidazol-1-yl]pent-4-enoate (127 mg, 0.42 mmol, 14% yield).

1. temperatureto warm to room temperature
2. stirringstirred for 2 h
3. extractionthe mixture was then extracted with EtOAc (2×100 mL)
4. washThe combined EtOAc layers were then washed with brine (50 mL)
5. dry with materialdried (MgSO4)
6. concentrationconcentrated in vacuo
7. custompurified by flash chromatography (SiO2, 80% EtOAc/hexanes)

ORD record

ord-a7b1afa052ef4b1a87d015ec95d3edc3

Source dataset

uspto-grants-2015_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09169248B2