Hydrochloric Acid → 4-Dibenzofuranol

Participants

Reaction Conditions

Reaction Steps

To a solution of dibenzofuran (50 g, 0.29 mol) in 1000 ml dry diethyl ether and N,N,N′,N′-tetramethylethane-1,2-diamine (70 ml, 0.43 mol) (TMEDA), 1.6M BuLi (235 ml, 0.32 mol) in hexanes was added with stirring under Nitrogen. The mixture was refluxed for 1 hour (yellow precipitate) and then cooled to 0° C. Tributyl borate (120 ml, 0.43 mol) was added until the precipitate disappeared. The reaction mixture is allowed to reach room temperature. After cooling again to 0° C., 125 ml of 30% hydrogen peroxide (H2O2) solution was added drop wise with vigorous stirring (light yellow precipitate). This mixture was refluxed for 1.5 hours, then cooled to 0° C. and acidified with 5M HCl. The organic phase was washed with cold 10% sodium sulphite solution and extracted with 2M sodium hydroxide. The combined aqueous extract was acidified, extracted with ethyl acetate and dried on sodium sulfate. Evaporation gave an orange oil which was filtered and isolated by column chromatography eluting with 15% ethyl acetate/hexane, yielding the product dibenzofuran-4-ol as an off-white solid. Yield 44 g (81%) 1H-NMR (300 MHz, CDCl3) 7.95 (d, J=7.5, 1H); 7.60 (d, J=8.4, 1H); 7.53 (dd, J=7.8, 1H); 7.48 (t, J=8.4, 1.2, 1H); 7.36 (t, J=7.5, 1.2, 1H); 7.23 (t, J=7.8, 1H); 7.03 (dd, J=8.1, 1.0, 1H); 5.50 (s, OH)

Provenance & Evidence