Reaction #50463

Reaction equation

5-nitro-4-ethylisatin

hydrogen peroxide

HCl

→

5-nitro-6-ethyl-2-aminobenzoic acid

Yield 82.5%

Solvents

NaOH

Conditions

Workup

1. 1
   Otherover 10 minutes
2. 2
   workup.ADDITIONpoured
3. 3
   Otherover crushed ice
4. 4
   ExtractionThe suspension was extracted 3× with ethyl acetate
5. 5
   WashThe combined organic extracts were washed 1× with water
6. 6
   Dryingdried over MgSO4
7. 7
   Concentrationconcentrated in vacuo
8. 8
   OtherThere was obtained a dark oil, which
9. 9
   Otherupon standing at room temperature

Procedure

To a solution of 1.0 g (4.5 mmoles) of 5-nitro-4-ethylisatin in 8.0 mL of 5% NaOH was slowly added 1.25 mL (11 mmoles) of 30% hydrogen peroxide over 10 minutes. A mild exotherm was detectable. The solution was stirred at room temperature for 60 minutes, then poured over crushed ice. The solution was acidified with 10% HCl until the `cloud point`. The suspension was extracted 3× with ethyl acetate. The combined organic extracts were washed 1× with water, dried over MgSO4, and concentrated in vacuo. There was obtained a dark oil, which upon standing at room temperature, became an orange-rust colored solid. 0.78 g (82% yield) of 5-nitro-6-ethyl-2-aminobenzoic acid was obtained. NMR(DMSO-d6): 1.16(t,3H,J=7.2 Hz), 2.88(q,2H,J=7.2 Hz), 3.34(bs,2H), 6.66(d,1H,J=9.3 Hz), 7.84(d,1H,J=9.3 Hz). MS(m/z): 210(M+).

Source