Carbon Dioxide → HCID 135738540, compound

Participants

Reaction Conditions

Reaction Steps

n-Butyllithium (2.5 M solution in hexane, 2.0 ml, 0.005 mol) was added dropwise to a stirred solution of 6-(5-bromo-2-ethoxyphenyl)-1-n-propyl-1,5-dihydro-4H-pyrazolo[3, 4-d]pyrimidin-4-one (0.755 g, 0.002 mol) in dry THF (20 ml) at −78° C. under a dry nitrogen atmosphere. The bright yellow solution was stirred for 1 hour at −78° C., then excess crushed solid carbon dioxide was added and the resulting solution was allowed to warm to room temperature. Saturated aqueous ammonium chloride solution (3 ml) was then added and the solvents removed by evaporation under vacuum. The residue was partitioned between saturated aqueous sodium carbonate solution (30 ml) and dichloromethane (30 ml), the organic phase was removed and the aqueous phase extracted with further dichloromethane (3×30 ml). The aqueous phase was then acidified to pH 1 with concentrated hydrochloric acid and extracted with ethyl acetate (5×40 ml). The combined ethyl acetate extracts were dried (Na2SO4) and the solvent removed by evaporation under vacuum to give a white solid. Crystallisation from ethyl acetate-methanol gave the title compound as a white powder (0.130 g, 19%), m.p. 277-279° C. Found: C,59.64; H,5.19; N,16.39. C17H18N4O4 requires C,59.64; H,5.23; N,16.37%.

Provenance & Evidence