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

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)+].

1. filtrationthe reaction mixture was filtered through a pad of Celite® (a diatomite
2. filtrationfilter from World Minerals Inc
3. wash), and then washed with isopropanol (200 mL)
4. additionThe combined filtrates were treated with charcoal at 50° C. for 1 hour
5. filtrationwere filtered through a pad of Celite® (diatomite filter)
6. customIsopropanol was removed
7. additionthe resulting solution was adjusted to a pH of about 2 by the slow addition of concentrated hydrochloric acid, during which a solid precipitate
8. customThe solid was collected
9. washwashed with water (100 mL×2)
10. customdried under high vacuum at 50° C.

ORD record

ord-d17caaa3f56d4391b119d84941b49ba4

Source dataset

uspto-grants-2012_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08163781B2