1,5-Dihydroxynaphthalene → 5-Hydroxy-1-tetralone

Participants

Reaction Steps

To a mixture of 1,5-dihydroxynaphthalene (25.0 g, 156 mmol) in isopropanol (150 mL) and an aqueous (40 mL) solution of sodium hydroxide (6.3 g, 157 mmol) was added 10% palladium on carbon (3.9 g) at room temperature. The reaction mixture was put under 100 psi hydrogen in a Parr autoclave (from Parr Instrument Company) at 80° C. for 20 hours. After being cooled to room temperature, the reaction mixture was filtered through a pad of Celite® (a diatomite filter from World Minerals Inc.), and then washed with isopropanol (200 mL). The combined filtrates were treated with charcoal at 50° C. for 1 hour, and then were filtered through a pad of Celite® (diatomite filter). Isopropanol was removed, and the resulting solution was adjusted to a pH of about 2 by the slow addition of concentrated hydrochloric acid, during which a solid precipitate appeared. The solid was collected, and washed with water (100 mL×2), and then dried under high vacuum at 50° C. to give 5-hydroxy-3,4-dihydro-2H-naphthalen-1-one (15.0 g, 60%) as a dark brown solid, which was used in the next step without further purification. MS cald. (calculated) for C10H10O2 162, obsd. (observed) 163 [(M+H)+].

Provenance & Evidence