3-Aminobenzoic Acid → 3-Hydrazinobenzoic acid hydrochloride

To a solution of m-aminobenzoic acid (200 g, 1.46 mmol) in conc. HCl (200 mL) was added an aqueous solution (250 mL) of NaNO2 (102 g, 1.46 mmol) at 0° C. and the reaction mixture was stirred for 1 h. A solution of SnCl2.2H2O (662 g, 2.92 mmol) in conc. HCl (2 L) was then added at 0° C. The reaction solution was stirred for an additional 2 h at RT. The precipitate was filtered and washed with EtOH and ether to give 3-hydrazinobenzoic acid hydrochloride as a white solid, which was used for the next reaction without further purification. 1H NMR (400 MHz, DMSO-d6): δ 10.8 (s, 3H), 8.46 (s, 1H), 7.53 (s, 1H), 7.48 (d, J=7.6 Hz, 1H), 7.37 (m, 1H), 7.21 (d, J=7.6 Hz, 1H).

1. stirringThe reaction solution was stirred for an additional 2 h at RT
2. filtrationThe precipitate was filtered
3. washwashed with EtOH and ether

ORD record

ord-7b7490e985bf458f8156e3b70198269b

Source dataset

uspto-grants-2012_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08163756B2