Reaktion #942126

Reaktionsgleichung

5-chloro-7-methyl-1H-indole-2,3-dione

potassium hydroxide

hydrogen peroxide

ethyl acetate

→

2-amino-5-chloro-3-methylbenzoic acid

Lösungsmittel

methanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   Extraktionextracted with I N hydrochloric acid (3×200 mL)
2. 2
   TrocknenThe solution was dried over sodium sulfate and solvent
3. 3
   Sonstigeremoved at reduced pressure

Vorschrift

The 5-chloro-7-methyl-1H-indole-2,3-dione (25.0 g, 0.13 mol), potassium hydroxide (8.4 g, 0.15 mmol) and 30% hydrogen peroxide (21.6 g, 0.18 mol) were mixed together in methanol (300 mL) at 0° C. for 2 h followed by 16 h at room temperature. The solution was poured into ethyl acetate (500 mL) and extracted with I N hydrochloric acid (3×200 mL) followed by brine (1×50 mL). The solution was dried over sodium sulfate and solvent removed at reduced pressure. The 2-amino-5-chloro-3-methylbenzoic acid (18.0 g, 0.10 mmol) was isolated as a yellow solid (75% yield). HRMS m/z 185.0238; calcd 185.0244.

Quelle