Dimethylacetamide → HCID 22477856, compound

Participants

Reaction Steps

A solution of 5,6-dimethyl-1-(2-trimethylsilanyl-ethoxymethyl)-1H-benzoimidazole [15.01 g, Reference Example 4(a)] in dry tetrahydrofuran (55 mL), at −78° C., was treated with a solution of lithium diisopropylamide in a mixture of tetrahydrofuran and heptane (11.9 mL, 2M) over 10 minutes. The mixture was stirred for 15 minutes then treated dropwise with dimethylacetamide (2.15 mL) over 10 minutes. After stirring at −78° C. for a further 30 minutes the reaction mixture was poured into ice (50 g) and then left until all the ice had melted. This mixture was extracted with dichloromethane and the extracts were washed with brine, then with water, then dried over magnesium sulfate and then evaporated. The residual orange oil (5.91 g) was subjected to column chromatography on silica eluting with a mixture of petroleum ether and ethyl acetate (4:1, v/v) to give 1-[5,6-dimethyl-1-(2-trimethylsilanyl-ethoxymethyl)-1H-benzoimidazol-2-yl]-ethanone (3.93 g) as a yellow crystalline solid.

Provenance & Evidence