Lithium Carbonate → 7-Bromonaphthalen-1-ol

A solution of tetrabutylammonium tribromide (11.8 g, 24.4 mmol) in dichloromethane (80 ml) was added dropwise to a solution of the product from Step C (5.0 g, 22.2 mmol) in dichloromethane (20 ml) and methanol (20 ml) at room temperature over 1 hour. At completion of the addition, the mixture was stirred at room temperature for 15 hours and was then concentrated. The residue was taken into dichloromethane and was washed with saturated sodium bicarbonate three times. The organic layer was concentrated and the residue was dissolved in dimethylformamide (100 ml). Lithium carbonate (5.3 g, 71.1 mmol) and lithium bromide (4.1 g, 46.6 mmol) were added and the resulting mixture was stirred at 140° C. for 1.5 hours. After cooling to room temperature, the solids were filtered and rinsed with ethyl acetate. The filtrate was washed with water four times and dried over sodium sulfate to give 7-bromonaphthalen-1-ol (2.7 g, 56%): 1H NMR (300 MHz, CDCl3) δ 8.41 (d, J=1.8 Hz, 1H), 7.68 (d, J=8.7 Hz, 1H), 7.57 (dd, J=8.7, 1.8 Hz, 1H), 7.41 (d, J=8.4 Hz, 1H), 7.28-7.35 (m, 1H), 6.62 (d, J=7.2 Hz, 1H), 5.80 (br s, 1H).

1. additionAt completion of the addition
2. concentrationwas then concentrated
3. washwas washed with saturated sodium bicarbonate three times
4. concentrationThe organic layer was concentrated
5. dissolutionthe residue was dissolved in dimethylformamide (100 ml)
6. stirringthe resulting mixture was stirred at 140° C. for 1.5 hours
7. temperatureAfter cooling to room temperature
8. filtrationthe solids were filtered
9. washrinsed with ethyl acetate
10. washThe filtrate was washed with water four times
11. dry with materialdried over sodium sulfate

ORD record

ord-fd2d9913a85d49bc8b0a224ab3ec60c9

Source dataset

uspto-grants-2009_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07541357B2