Nitric Acid → 2,5-Dichloro-3-nitrobenzoic acid

HRID 1438846Notes

Reaction equation

HRID 1438846 reaction equation
[Cl:1][C:2]1[CH:10]=[CH:9][C:8]([Cl:11])=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].[N+:12]([O-])([OH:14])=[O:13]>S(=O)(=O)(O)O>[Cl:1][C:2]1[C:10]([N+:12]([O-:14])=[O:13])=[CH:9][C:8]([Cl:11])=[CH:7][C:3]=1[C:4]([OH:6])=[O:5]

Participants

4

Reactant 2

HCID 944Nitric AcidHCID 57842,5-Dichlorobenzoic acid

Product 1

HCID 69512,5-Dichloro-3-nitrobenzoic acidYield 84%

Reagents, catalysts & solvents 1

HCID 1118Sulfuric AcidSolvent2×

Procedure

950 g (5 moles) of 2,5-dichloro-benzoic acid were suspended in 6 l of concentrated sulfuric acid. A mixture of 500 g of concentrated sulfuric acid and 400 g of nitric acid (D = 1.5) was added dropwise at 5° C to 10° C. The reaction mixture was stirred for 15 hours at 20°-25° C and was then poured onto 40 kg of ice. The precipitate which had separated out was filtered off, washed with 20 l of water and dried. The ultimate purification was carried out by recrystallization from 1.7 l of acetonitrile/water (9:1). 990 g (84% of theory) of 2,5-dichloro-3-nitrobenzoic acid were obtained in the form of colorless crystals of melting point 216°-218° C (with decomposition).

Workup

  1. additionwas added dropwise at 5° C to 10° C
  2. customThe precipitate which had separated out
  3. filtrationwas filtered off
  4. washwashed with 20 l of water
  5. customdried
  6. customThe ultimate purification
  7. customwas carried out by recrystallization from 1.7 l of acetonitrile/water (9:1)

Sources & evidence

ORD record
ord-e556e5af97e2466283628511e6c9e474
Source dataset
uspto-grants-1977_11
Patent number
US04057418

Reaction notes

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