Stannous Chloride → Methyl 3,4-diaMino-5-broMobenzoate

Temperature

60 °C

A suspension of methyl 4-amino-3-bromo-5-nitrobenzoate (10 g, 36.3 mmol) and tin(II) chloride (33 g, 14.5 mmol) in methanol (100 mL) was heated to 60° C. and maintained for 4 hours. The reaction mass was cooled to ambient temperature and concentrated to obtain a residue; the residue was basified using saturated aqueous sodium bicarbonate until pH was 11 and the aqueous layer was extracted with dichloromethane (3×200 mL). The combined organic layers were washed with aqueous saturated sodium chloride (200 mL), dried over anhydrous sodium sulfate and concentrated to obtain methyl 3,4-diamino-5-bromobenzoate as an off-white solid (5 g, 58%). 1HNMR (CDCl3): δ ppm 7.74 (s, 1H), 7.35 (s, 1H), 4.18 (broad s, 2H), 3.85 (s, 3H) and 3.38-3.56 (broad s, 2H).

1. temperaturemaintained for 4 hours
2. temperatureThe reaction mass was cooled to ambient temperature
3. concentrationconcentrated
4. customto obtain a residue
5. extractionthe aqueous layer was extracted with dichloromethane (3×200 mL)
6. washThe combined organic layers were washed with aqueous saturated sodium chloride (200 mL)
7. dry with materialdried over anhydrous sodium sulfate
8. concentrationconcentrated

ORD record

ord-91a0709c7d2a4859a066eff56efd10d7

Source dataset

uspto-grants-2014_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08802690B2