Hexane → Methyl 2-[(3-oxo-1,2,3,4-tetrahydroquinoxalin-6-yl)carbonyl]benzoate

A solution of phenylmethyl 2-{[3-nitro-4-({2-oxo-2-[(phenylmethyl)oxy]ethyl}amino)phenyl]carbonyl}benzoate (0.31 g, 0.59 mmol) in a mixture of tetrahydrofurane-ethyl acetate (1:1, 50 mL) was hydrogenated in the presence of 10% Pd/C (0.15 g) in a Parr shaker at 40 psi, until the consumption of hydrogen ceased. The catalyst was filtered off and the solvent was evaporated. The resulting crude product was converted into its methyl ester in a mixture of benzene-methanol (9:1, 5.0 mL) by the addition of 2.0 M trimethylsilyldiazomethane solution in hexane (0.3 mL, 0.60 mmol). The reaction was quenched by the addition of a few dropps of acetic acid and the solvent was evaporated. The resulting crude product was purified by silica gel flash chromatography (hexane:ethyl acetate 4:1 to 1:1 eluent) to give methyl 2-[(3-oxo-1,2,3,4-tetrahydroquinoxalin-6-yl)carbonyl]benzoate (0.12 g, 67% yield). 1H NMR (400 MHz, DMSO-d6): 8.06 (s, 1H), 7.83 (dd, 1H), 7.64 (d, 1H), 7.52 (t, 1H), 7.38 (d, 1H), 7.09 (7.03 (d, 1H), 4.41 (s, 2H), 3.77 (s, 3H); MS (EI) for C17H14N2O4: 311 (MH+).

1. customwas hydrogenated in the presence of 10% Pd/C (0.15 g) in a Parr shaker at 40 psi, until the consumption of hydrogen
2. filtrationThe catalyst was filtered off
3. customthe solvent was evaporated
4. customThe reaction was quenched by the addition of a few dropps of acetic acid
5. customthe solvent was evaporated
6. customThe resulting crude product was purified by silica gel flash chromatography (hexane:ethyl acetate 4:1 to 1:1 eluent)

ORD record

ord-48eaec298baa40058814f5507b8534a4

Source dataset

uspto-grants-2010_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07846959B2