Acetic Acid → (R)-3-[2,4-dioxo-1-(1,4,6-trimethyl-1H-indol-3-ylmethyl)-1,4-dihydro-2H-pyrido[3,2-d]pyrimidin-3-yl]-pentanoic acid

Participants

Reaction Steps

A solution of 1.0 g of (R)-3-[2,4-dioxo-1-(1,4,6-trimethyl-1H-indol-3-ylmethyl)-1,4-dihydro-2H-pyrido[3,2-d]pyrimidin-3-yl]-pentanoic acid methyl ester and 187 mg of lithium hydroxide monohydrate in 20 mL water and 20 mL of 1,4-dioxane is stirred at room temperature for 3 h. The resulting mixture is neutralized with 0.26 mL of acetic acid and the resulting mixture is diluted with water. The product is extracted with ethyl acetate. The organic layer is washed with water and brine, dried (sodium sulfate), filtered and concentrated. The residue is purified by flash chromatography on silica gel. The combined fractions are concentrated and the residue is triturated with ether to give 410 mg (42%) of (R)-3-[2,4-dioxo-1-(1,4,6-trimethyl-1H-indol-3-ylmethyl)-1,4-dihydro-2H-pyrido[3,2-d]pyrimidin-3-yl]-pentanoic acid; LCMS (ESMS): m/z 435 (M+H+).

Provenance & Evidence