Hydrochloric Acid → Methyl 4,5-diamino-2-hydroxybenzoate

Reaction equation

[NH2:1][C:2]1[C:11]([N+:12]([O-])=O)=[CH:10][C:5]([C:6]([O:8][CH3:9])=[O:7])=[C:4]([OH:15])[CH:3]=1.Cl>CO.[Fe]>[NH2:1][C:2]1[C:11]([NH2:12])=[CH:10][C:5]([C:6]([O:8][CH3:9])=[O:7])=[C:4]([OH:15])[CH:3]=1

Participants

Procedure

To a solution of methyl 4-amino-2-hydroxy-5-nitrobenzoate (step 5 of intermediate-1) (0.500 g, 2.35 mmol) in methanol (15.0 mL), iron powder (0.646 g, 11.7 mmol) was added with conc. HCl (5 mL). The reaction mass was refluxed for 2 h. Methanol was removed under vacuum and then water was added. The reaction mass was basified with Na2CO3 and extracted with DCM. The organic layer was dried over anhydrous sodium sulphate and concentrated to afford 0.500 g of the desired product. 1HNMR (DMSO-d6): δ 3.76 (s, 3H), 4.29 (s, 2H), 5.64 (s, 2H), 6.01 (s, 1H), 6.89 (s, 1H), 10.28 (s, 1H).