Potassium Carbonate → HCID 59803681, compound

Participants

Reaction Steps

The crude 8-[(3,4-dimethoxyphenyl)ethynyl]-7-methyl-1-prop-2-ynyl-3,7-dihydro-1H-purine-2,6-dione (ca. 452 mg, 1.24 mmol), contaminated with the starting material and with the dimethylated derivative (8-[(3,4-dimethoxyphenyl)ethynyl]-3,7-dimethyl-1-prop-2-ynyl-3,7-dihydro-1H-purine-2,6-dione), was suspended in dry DMF (7 mL). Subsequently dry potassium carbonate (514 mg, 3.72 mmol) and chloromethyl pivalate (654 mg, 4.34 mmol) was added. The mixture was stirred at room temperature for 3 h (TLC-control: dichloromethane/methanol, 9.5:0.5, Rf=0.60 for the main product) and the product was precipitated by adding water (30 mL), filtered under reduced pressure and dried at 70° C. The crude product was dissolved in a minimum of ethyl acetate (by slightly heating) and purified by column chromatography (eluent: petroleum ether/ethyl acetate, 1:1) affording 471 mg (79% yield over two steps) of {8-[(3,4-dimethoxyphenyl)ethynyl]-7-methyl-2,6-dioxo-1-prop-2-ynyl-1,2,6,7-tetrahydro-3H-purin-3-yl}methyl pivalate as a colorless solid.

Provenance & Evidence