Diethyl Ether → HCID 19955604, compound

Participants

Reaction Steps

Chloromethyl pivalate (3.22 g) was added, dropwise, at ambient temperature, to a stirring suspension of 3-[4'-(2-ethyl-5,7-dimethyl-3H-imidazo[4,5-b]pyrid-3-ylmethyl)biphenyl -2-yl]-4-hydroxycyclobut-3-ene-1,2-dione (4.21 g; preparable as in Example 4) in dry N,N-dimethylacetamide (40 ml). Potassium iodide (2.5 g) was added to the resulting mixture and stirring was continued am ambient temperature for 2 days. More chloromethyl pivalate (3.7 g) was added and stirring was continued for an additional 2 days. The mixture obtained was poured into diethyl ether (500 ml) to give a gum which was separated and then dissolved in a mixture of acetone (100 ml) and ethyl acetate (300 ml). The resulting solution was washed with saturated aqueous sodium bicarbonate solution (2×400 ml) then water (2×400 ml) and dried over magnesium sulphate. The solvents were evaporated under reduced pressure and the residue obtained was purified by flash chromatography on silica gel (eluting with ethyl acetate) to give 2-[4'-(2-ethyl-5,7-dimethyl-3H-imidazo[4,5-b]pyrid-3-ylmethyl)biphenyl-2-yl]-3,4-dioxocyclobut-1-en-1-yloxymethyl pivalate, an active compound of the present invention, as a fellow foam (0.54 g) which melted slowly at 60°-80° C.

Provenance & Evidence