(2-{[3-(1,3-Dioxo-1,3-dihydro-isoindol-2-yl)-3-methyl-butyrylamino]-methyl}-pyridin-3-yloxy)-acetic acid ethyl ester → {3-[2-(1,3-Dioxo-1,3-dihydro-isoindol-2-yl)-2-methyl-propyl]-imidazo[1,5-a]pyridin-8-yloxy}-acetic acid ethyl ester

Participants

Reaction Steps

A solution of (2-{[3-(1,3-dioxo-1,3-dihydro-isoindol-2-yl)-3-methyl-butyrylamino]-methyl}-pyridin-3-yloxy)-acetic acid ethyl ester (2.79 g, 6.349 mmol) in 100 ml of neat phosphoryl chloride is stirred at 75° C. for 16 hours. The reaction mixture is poured on 200 g of crushed ice and extracted with methylene chloride. The organic phase is dried over sodium sulfate and evaporated. The residue is purified via flash chromatography on silica gel using a methylene chloride/methylene chloride-ethanolic ammonia gradient (100 to 96:4) to give 1.48 g of {3-[2-(1,3-dioxo-1,3-dihydro-isoindol-2-yl)-2-methyl-propyl]-imidazo[1,5-a]pyridin-8-yloxy}-acetic acid ethyl ester (55%).

Provenance & Evidence