Benzoic acid, 4-hydroxy-3-nitro-, methyl ester → Methyl 3-amino-4-hydroxybenzoate

Participants

Reaction Steps

To a 2000 ml three-necked flask containing 3-Nitro-4-hydroxy-benzoic acid methyl ester (43 g, 2188 mmol) in MeOH (860 ml; 20 vols) was added palladium on carbon in water (2 g in 10 ml of water). Ammonium formiate (68.76 g, 5 eq.) was added in a single portion under stirring. After 2 to 3 minutes a suspension was observed, and temperature raised from 20° C. to 30° C. Ice bath was used to cool reaction mixture to 20° C. and the reaction was stirred at 20° C. for 40 minutes until completion (no more yellow color). Reaction mixture was filtered on silica plug, rinsed with MeOH, and the filtrate was concentrated under vacuum to give a green oil which was taken up in ethyl acetate (400 ml). The organic phase was washed twice with water, dried over MgSO4, filtered and concentrated to give a cream solid m=31.35 g (86%).

Provenance & Evidence