Sulfuric Acid → 2-(Methoxycarbonyl)-6-nitrobenzoic acid

Reaction equation

[N+:1]([C:4]1[CH:12]=[CH:11][CH:10]=[C:6]([C:7]([OH:9])=[O:8])[C:5]=1[C:13]([OH:15])=[O:14])([O-:3])=[O:2].[CH:16]([O-])([O-])OC.S(=O)(=O)(O)O>CO>[C:13]([C:5]1[C:4]([N+:1]([O-:3])=[O:2])=[CH:12][CH:11]=[CH:10][C:6]=1[C:7]([O:9][CH3:16])=[O:8])([OH:15])=[O:14]

Participants

Procedure

To a suspension of 3-nitrophthalic acid (211 g) and methyl orthoformate (127 g) in methanol (420 ml) was added conc. sulfuric acid (20 ml) dropwise with stirring. The reaction mixture was heated under reflux for 18 hours and concentrated to dryness. After addition of water (30 ml) to the residue, the mixture was stirred at 3-10° C. for one hour. The precipitated crystals were recrystallized from ethyl acetate-hexane to give pale yellow prisms (185 g, 82%), m.p. 166-1680° C.