2-Bromoethanol → 1H-Pyrazolo(3,4-b)pyridine-1-ethanol, 3-(3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl)-

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Reaction Conditions

Reaction Steps

To a solution of 5 g of 3-(3,5-di-tertiary butyl-4-hydroxyphenyl)-1H-pyrazolo[3,4-b]pyridine in 40 ml of dimethylformamide are added 2.5 g of 2-bromoethanol and 2.8 g of potassium carbonate. After stirring at 65° C. for 12 hours, the resulting mixture is poured into ice-cold water and the precipitate is extracted with ethyl acetate. The ethyl acetate layer is washed with water, dried and then concentrated. The residue is recrystallized from a mixed solvent of hexane and toluene to give 4.6 g of 3-(3,5-di-tertiary butyl-4-hydroxyphenyl)-1-(2-hydroxyethyl)-1H-pyrazolo[3,4-b]pyridine as pale yellow crystals, melting at 135°-137° C.

Provenance & Evidence