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. This oil was triturated with hexane to afford a white solid (3.2 g, 77.6%). 1H NMR (300 MHz, CDCl3): δ ppm 0.63 (m, 1H), 0.76 (t, J=7.35 Hz, 3H), 0.99 (m, 1H), 1.18 (m, 2H), 2.04 (m, 1H), 2.26 (m, 1H), 3.55 (d, J=3.68 Hz, 2H), 3.61 (s, 3H), 3.63 (s, 3H), 5.05 (t, J=3.68 Hz, 1H), 7.16 (m, 4H); MS (ESI) m/z 275.1 (M+H)+.

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レコード

ord-648bd00480864e4da8074a4b6dddd62c

出典データセット

uspto-grants-2009_05

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US07538105B2