Reaction equation
[F:1][C:2]([F:16])([F:15])[O:3][C:4]1[CH:5]=[C:6]2[C:10](=[CH:11][CH:12]=1)[NH:9]C(=O)[C:7]2=[O:14].[OH-].[K+].OO.C(O)(=[O:23])C>O>[NH2:9][C:10]1[CH:11]=[CH:12][C:4]([O:3][C:2]([F:1])([F:16])[F:15])=[CH:5][C:6]=1[C:7]([OH:14])=[O:23]Participants
Conditions
- Temperature
- 0 °C
Procedure
5-(Trifluoromethoxy)isatin (15.0 g, 65 mmol) and potassium hydroxide pellets (4 g) were mixed in water (35 mL) and cooled to 0° C. With vigorous stirring, a solution of 30% aqueous hydrogen peroxide (11.7 g), potassium hydroxide pellets (5.8 g), and water (80 mL) was added drop-wise keeping the temperature below 10° C. After stirring 1 hour at 0° C., glacial acetic acid (22 mL) was added drop-wise, causing foaming and formation of a precipitate. The contents were stirred overnight and filtered to afford the 2-amino-5-trifluoromethoxybenzoic acid as an amber solid (12.5 g, 87%). A small amount was recrystallized from ethyl acetate-hexanes to afford amber needles for an analytical sample and the remaining compound was used without further purification: mp 142.5–144.2° C. 1H NMR (CDCl3, 300 MHz) 7.98 (s, 1H), 7.18 (d, 1H, J=8.0 Hz) 6.62 (d, 1H, J=8.0 Hz), 6.40 (brs, 2H). Anal. Calc'd for C8H6NO3F3: C, 43.45; H, 2.73; N, 6.33. Found: C, 43.40; H, 2.65; N, 6.35.
Workup
- customthe temperature below 10° C
- stirringThe contents were stirred overnight
- filtrationfiltered
Sources & evidence
- ORD record
- ord-0a92c2dfede9405790d56cf16661bad2
- Source dataset
- uspto-grants-2006_11
- Patent number
- US07138411B2
Linked notes
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