Dimethyl Carbonate → 1,1-dimethylethyl 7-[3-(methyloxy)-3-oxopropanoyl]-2,3-dihydro-1,4-benzoxazepine-4(5H)-carboxylate

A solution of 1,1-dimethylethyl 7-acetyl-2,3-dihydro-1,4-benzoxazepine-4(5H)-carboxylate (1.34 g, 4.60 mmol) in tetrahydrofuran (5 mL) was added to a suspension of sodium hydride (60% oil suspension, 0.80 g, 13.3 mmol) in tetrahydrofuran (20 mL) and the resulting mixture was stirred at room temperature for 5 minutes. Dimethyl carbonate (5 mL) was added and the resulting mixture was stirred at 65° C. for twenty minutes. Then the reaction mixture was cooled, quenched with ice (20 g) and aqueous ammonium chloride (20 mL) then extracted with ethyl acetate (3×40 mL). The combined organic extract was washed with water, then brine solution (80 mL each), dried over sodium sulfate, filtered, concentrated, and purified by silica gel chromatography (25% ethyl acetate in hexanes) to give 1,1-dimethylethyl 7-[3-(methyloxy)-3-oxopropanoyl]-2,3-dihydro-1,4-benzoxazepine-4(5H)-carboxylate (0.94 g, 59% yield). MS (EI) for C18H23NO6: 350 (MH+).

1. stirringthe resulting mixture was stirred at 65° C. for twenty minutes
2. temperatureThen the reaction mixture was cooled
3. customquenched with ice (20 g) and aqueous ammonium chloride (20 mL)
4. extractionthen extracted with ethyl acetate (3×40 mL)
5. extractionThe combined organic extract
6. washwas washed with water
7. dry with materialbrine solution (80 mL each), dried over sodium sulfate
8. filtrationfiltered
9. concentrationconcentrated
10. custompurified by silica gel chromatography (25% ethyl acetate in hexanes)

ORD record

ord-3788723d8611468b8c29fd83920aeee9

Source dataset

uspto-grants-2014_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08637499B2