Methanol → Methyl 2-Amino-4-(trifluoromethyl)benzoate
Reaction equation
[NH2:1][C:2]1[CH:10]=[C:9]([C:11]([F:14])([F:13])[F:12])[CH:8]=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].S(=O)(=O)(O)O.[CH3:20]O>>[CH3:20][O:5][C:4](=[O:6])[C:3]1[CH:7]=[CH:8][C:9]([C:11]([F:12])([F:13])[F:14])=[CH:10][C:2]=1[NH2:1]Participants
4
Procedure
To a solution of 2-amino-4-trifluoromethyl-benzoic acid (72.0 g, 351 mmol) in MeOH (1000 mL) was added dropwise concentrated sulfuric acid (50 mL). The mixture was heated to reflux for 16 h under nitrogen, allowed to cool to r.t., and then concentrated in vacuo to ¼ of its volume. The mixture was taken up in EtOAc and washed with water, 10% aqueous solution of sodium carbonate, and brine. It was then dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. Purification by column chromatography (silica gel 60, hexanes/EtOAc 9:1) furnished 2-amino-4-trifluoromethyl-benzoic acid methyl ester (57.8 g, 264 mmol, 75%) as a white powder, m.p. 59° C., ESI-MS: m/z 218 [M−H]−.
Workup
- temperatureThe mixture was heated
- temperatureto reflux for 16 h under nitrogen
- concentrationconcentrated in vacuo
- washwashed with water, 10% aqueous solution of sodium carbonate, and brine
- dry with materialIt was then dried over anhydrous sodium sulfate
- filtrationfiltered
- concentrationconcentrated in vacuo
- customPurification by column chromatography (silica gel 60, hexanes/EtOAc 9:1)
Sources & evidence
- ORD record
- ord-fb762b2e927c48d7ad86b4f36d0ba272
- Source dataset
- uspto-grants-2011_09
- Patent number
- US08012988B2
Reaction notes
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