Ammonia → Methyl 1-butyl-2-methoxy-1,4-dihydronaphthalene-1-carboxylate

To a stirred solution of methyl 2-methoxynaphthoate (3.25 g, 15 mmol) and tert-butyl alcohol (1.48 ml, 15 mmol) in tetrahydrofuran (10 mL) at −78° C. was added liquid ammonia (60 mL). Potassium metal (2.9 g, 75 mmol) was added in small pieces until the solution stayed dark blue for 30 min. Butyl iodide (5.47 mL, 48 mmol) was added dropwise (the blue coloration disappeared about half-way through addition) and stirring was continued for 1 hour at −78° C. The solution was allowed to warm to room temperature and purged with nitrogen to remove excess ammonia. To the resulting slurry a solution of saturated sodium bicarbonate (100 mL) was added, and the solution was extracted with ether (3×50 mL). The combined organic phases were washed with 10% Na2S2O3 (aq), dried (Na2SO4), and concentrated in vacuo. Column chromatography on silica (20% ethyl acetate/hexane) gave the title compound as a light yellow oil. This oil was triturated with hexane to afford a white solid (3.2 g, 77.6%).

1. additiondisappeared about half-way through addition) and
2. waitwas continued for 1 hour at −78° C
3. custompurged with nitrogen
4. customto remove excess ammonia
5. additionTo the resulting slurry a solution of saturated sodium bicarbonate (100 mL) was added
6. extractionthe solution was extracted with ether (3×50 mL)
7. washThe combined organic phases were washed with 10% Na2S2O3 (aq)
8. dry with materialdried (Na2SO4)
9. concentrationconcentrated in vacuo

ORD record

ord-a72f2db7e8ea45b1804058386e38b58a

Source dataset

uspto-grants-2009_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07517876B2