Hydrochloric Acid → 7-Formyl-3-hydroxy-2-naphthoic acid

Participants

Reaction Steps

A solution of 7-bromo-3-hydroxynaphthalene-2-carboxylic acid (15.0 g, 56.2 mmol) (example 340) in tetrahydrofuran (100 mL) was added to a solution of lithium hydride (893 mg, 112 mmol) in tetrahydrofuran (350 mL). After 30 minutes stirring at room temperature, the resulting solution was heated to 50° C. for 2 minutes and then allowed to cool to ambient temperature over a period of 30 minutes. The mixture was cooled to −78° C., and butyllithium (1.6 M in hexanes, 53 mL, 85 mmol) was added over a period of 15 minutes. N,N-Dimethylformamide (8.7 mL, 8.2 g, 112 mmol) was added after 90 minutes additional stirring. The cooling was discontinued, and the reaction mixture was stirred at room temperature for 17 hours before it was poured into 1 N hydrochloric acid (aq.) (750 mL). The organic solvents were evaporated in vacuo, and the resulting precipitate was filtered off and rinsed with water (3×100 mL) to yield the crude product (16.2 g). Purification on silica gel (dichloromethane/methanol/acetic acid=90:9:1) furnished the title compound as a solid.

Provenance & Evidence