Ammonium Acetate → (5-Amino-5,6,7,8-tetrahydro-naphthalen-1-yloxy)-acetic acid tert-butyl ester

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Reaction Steps

To a stirred solution of (5-oxo-5,6,7,8-tetrahydro-naphthalen-1-yloxy)-acetic acid tert-butyl ester (10.0 g, 36.2 mmol) in methanol (300 mL) was added ammonium acetate (55.0 g, 714 mmol) at room temperature under nitrogen. After being stirred for 4 hours at room temperature, the reaction mixture was cooled to 0° C. and sodium cyanoborohydride (5.7 g, 90 mmol) was added. The resulting mixture was allowed to warm to room temperature and stirred for an additional 48 hours. The reaction mixture was then concentrated under reduced pressure. To the residue was added saturated sodium carbonate solution to adjust the pH to about 7, and the resulting solution was extracted with ethyl acetate (500 mL×3). The combined organic layers were dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. Column chromatography (silica gel, 100-200 mesh, 2% to 5% methanol in dichloromethane) gave (5-amino-5,6,7,8-tetrahydro-naphthalen-1-yloxy)-acetic acid tert-butyl ester (4.6 g, 46%) as a solid. MS cald. for C16H23NO3 277. obsd. 278 [(M+H)+].

Provenance & Evidence