Ammonium Chloride → Methyl 3-amino-5-chloro-2-ethylbenzoate

Temperature

70 °C

To a solution of methyl 5-chloro-2-ethyl-3-nitrobenzoate (1.2 g, 5.0 mmol) in methanol (50 ml) and deionised water (25 ml), was added ammonium chloride (2.6 g, 50 mmol). The mixture was heated to 70° C. before the addition of iron (1.7 g, 30 mmol). The reaction mixture was stirred at 70° C. for 3.5 hours, hot filtered through Celite and the filter pad was washed with MeOH (20 ml). The filtrate was concentrated in-vacuo and the aqueous residue was dissolved in a saturated solution of NaHCO3(aq) (50 ml) and EtOAc (100 ml). The phases were separated and the organic phase was washed with saturated NaHCO3(aq) (2×65 ml), brine (30 ml), dried over MgSO4, filtered and concentrated in-vacuo. The residue was purified by column chromatography (25 g SNAP cartridge, Isolera, 0-11% ethyl acetate/heptanes) to give the title compound (372 mg, 33%) as a yellow oil. LC-MS 94%, m/z=213.9, 215.9; 1H NMR (500 MHz, Chloroform-d) d ppm 7.18 (d, J=2.21 Hz, 1H) 6.80 (d, J=2.05 Hz, 1H) 3.88 (s, 3H) 3.85 (d, J=2.52 Hz, 2H) 2.75 (q, J=7.57 Hz, 2H) 1.21 (t, J=7.49 Hz, 3H).

1. filtrationhot filtered through Celite
2. washthe filter pad was washed with MeOH (20 ml)
3. concentrationThe filtrate was concentrated in-vacuo
4. dissolutionthe aqueous residue was dissolved in a saturated solution of NaHCO3(aq) (50 ml) and EtOAc (100 ml)
5. customThe phases were separated
6. washthe organic phase was washed with saturated NaHCO3(aq) (2×65 ml), brine (30 ml)
7. dry with materialdried over MgSO4
8. filtrationfiltered
9. concentrationconcentrated in-vacuo
10. customThe residue was purified by column chromatography (25 g SNAP cartridge, Isolera, 0-11% ethyl acetate/heptanes)

ORD record

ord-1c3a8cb06bd64406872ff4d6ae8b41b9

Source dataset

uspto-grants-2016_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09376422B2