Carbon Dioxide → 1-Methoxy-2-naphthoic acid

Temperature

0 °C

Reference: J. Organomet. Chem., 20 (1969) p. 251-252.n-BuLi (208.60 mmol, 83.44 ml of a 2.5 M solution in hexane, Aldrich) was stirred under argon in 42 ml of dry cyclohexane. This solution was cooled to 0° C. and treated dropwise (10 min.) with distilled tetramethylethylenediamine (TMEDA) (208.6 mmol, 24.24 g, 31.48 ml). The resulting slurry was stirred at 0° C. for 30 minutes, then treated dropwise (20 minutes) with a solution of 1-methoxynaphthalene (208.60 mmol, 33 g, 30.28 ml) (Aldrich Chem. Co., used without: further purification) in 84 ml of dry cyclohexane. The resulting bright red homogeneous reaction mixture was warmed to room temperature and stirred for 2 hours. The reaction mixture was cooled to 0° C. and added portionwise over 30 minutes via cannula to a -78° C. solution of dry Et2O (250 ml) saturated with CO2 (g) (CO2 pellets sublimed through drying tube containing SiO2, bubbled into dry Et2O at -78° C.). The resulting white slurry was warmed to ~0° over 45 minutes and then treated with 450 ml of 5% HCl (aqueous). The Et2O layer was separated and the aqueous layer extracted three times with Et2O. The organic extracts were combined and extracted with 3×150 ml saturated NaHCO3 (aqueous). The aqueous layer was filtered through a sintered glass funnel to remove insolubles and the filtrate was cooled to 0° C. and acidified slowly with concentrated HCl until pH=1. The resulting precipitate was filtered, azeotroped with 2× 150 ml of toluene, dried under high vacuum at 50° C. for 5 hours to afford 32.52 g (0.161 mol, 77% yield) of the 1-methoxy-2-naphthalene carboxylic acid as an off-white powder, m.p. 118°-121.5° C.

1. temperatureThe resulting bright red homogeneous reaction mixture was warmed to room temperature
2. stirringstirred for 2 hours
3. temperatureThe reaction mixture was cooled to 0° C.
4. temperatureThe resulting white slurry was warmed to ~0° over 45 minutes
5. customThe Et2O layer was separated
6. extractionthe aqueous layer extracted three times with Et2O
7. extractionextracted with 3×150 ml saturated NaHCO3 (aqueous)
8. filtrationThe aqueous layer was filtered through a sintered glass funnel
9. customto remove insolubles
10. temperaturethe filtrate was cooled to 0° C.
11. filtrationThe resulting precipitate was filtered
12. customazeotroped with 2× 150 ml of toluene
13. customdried under high vacuum at 50° C. for 5 hours

ORD record

ord-3b5a604a357d4ea6ad86bdb7233886da

Source dataset

uspto-grants-1992_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05091378