Stannous chloride dihydrate → 2,3-Diaminobenzoic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

Tin(II)chloride dihydrate (17.25 g, 76.5 mmol) was added in one portion to methyl 2-amino-3-nitrobenzoate (5.0 g, 25.5 mmol) in methanol (100 mL) under nitrogen. The yellow mixture was vigorously stirred at 65° C. for 16 h, and the solvent was removed by rotary evaporation to near dryness. The residue was taken up in EtOAc and the solution was poured into a large beaker containing 1:1 EtOAc/NaHCO3 soln (300 mL) and stirred 15 min. The precipitates were removed by filtration and the organic layer was separated. The aqueous layer was extracted twice more with EtOAc, and the combined organic layer was washed with saturated NaHCO3 solution, brine, dried (Na2SO4), and filtered. Concentration of the filtrate gave methyl 2,3-diaminobenzoate as a deep red viscous oil (4.1 g, 97%).

Provenance & Evidence