Carbon Dioxide → 6-Hydroxy-2-naphthoic acid

Participants

Reaction Steps

To a slurry of 5.00 g (22.4 mmol, Aldrich) of 6-bromo-2-naphthol in 150 ml of dry ether at -78° was added dropwise, 16 ml (1.4M in ether, 22 mmol, Aldrich) of methyllithium solution over 10 minutes. The reaction mixture was stirred for 10 minutes, then 28 ml (1.8M in pentane, 50 mmol, Aldrich) of t-butyllithium solution was added dropwise over 15 minutes. The resulting slurry was stirred at -78° for 30 minutes then at 0° for 15 minutes. The reaction mixture was re-cooled to -78°, added into 100 g of crushed dry ice via cannula, and allowed to warm to room temperature over about ~2 hours, then added to 200 ml of 1M aqueous HCl solution and extracted with 100 ml of ethyl acetate. The organic extract was separated, washed with an additional 200 ml of H2O and concentrated in vacuo to give a pale yellow solid. The crude material was dissolved in 125 ml of warm, saturated aqueous NaHCO3 solution and extracted with two 50 ml portions of ethyl acetate. The aqueous phase was acidified to pH 1 with concentrated HCl. The solid which precipitated was collected on a Buchner funnel then dried under vacuum at 110° to afford 2.95 g (70%) of title compound as an off-white powder, m.p. 237°-241°.

Provenance & Evidence