Sulfuric Acid → 2-Bromo-4-nitrobenzoic acid

HRID 496629Notes

Reaction equation

HRID 496629 reaction equation
NC1C=CC(C(N[C@@H](CCSC)C(OC)=O)=O)=C(CC2C=CC=CC=2)C=1.[OH2:27].[OH2:28].[Cr](O[Cr]([O-])(=O)=O)([O-])(=O)=O.[Na+].[Na+].[Br:40][C:41]1[CH:46]=[C:45]([N+:47]([O-:49])=[O:48])[CH:44]=[CH:43][C:42]=1[CH3:50].S(=O)(=O)(O)O>C(O)(=O)C>[Br:40][C:41]1[CH:46]=[C:45]([N+:47]([O-:49])=[O:48])[CH:44]=[CH:43][C:42]=1[C:50]([OH:28])=[O:27]

Participants

6

Conditions

Temperature
105 °C

Procedure

Compound 21 used in the preparation of compound 24 was prepared as follows. Sodium dichromate dihydrate (151 gm) was added to glacial acetic acid (575 ml) followed by 2-bromo-4-nitro-toluene (49.7 gm). To this solution was added dropwise sulphuric acid (175 ml) at such a rate to maintain the temperature between. 75-85° C. This mixture was heated to 100-110° C. for 3 h cooled to 50° C. and poured onto ice (1 litre). The aqueous phase was extracted with ethyl acetate, the organic layer back extracted with Aqueous sodium hydroxide solution and the resulting basic aqueous layer acidified with concentrated hydrochloric acid. The precipitated solid was filtered, washed with water and air dried to give 15.72 gm (28%) of 2-bromo-4-nitro-benzoic acid (compound 26) as a white solid.

Workup

  1. customwas prepared
  2. temperatureto maintain the temperature between
  3. custom75-85° C
  4. temperaturecooled to 50° C.
  5. additionpoured onto ice (1 litre)
  6. extractionThe aqueous phase was extracted with ethyl acetate
  7. extractionthe organic layer back extracted with Aqueous sodium hydroxide solution
  8. filtrationThe precipitated solid was filtered
  9. washwashed with water and air
  10. customdried

Sources & evidence

ORD record
ord-1ec1c1a2f26544329c3a37db3fb3d4d3
Source dataset
uspto-grants-2005_09
Patent number
US06946468B1

Reaction notes

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