Hydrochloric Acid → 2,4-dichloro-5-nitrobenzoic acid

HRID 336423Notes

Reaction equation

HRID 336423 reaction equation
ClC1C([N+]([O-])=O)=C(Cl)C=CC=1C([O-])=O.[Na+].[Cl:16][C:17]1[CH:25]=[C:24]([Cl:26])[C:23]([N+:27]([O-:29])=[O:28])=[CH:22][C:18]=1[C:19]([O-:21])=[O:20].[Na+].Cl>O>[Cl:16][C:17]1[CH:25]=[C:24]([Cl:26])[C:23]([N+:27]([O-:29])=[O:28])=[CH:22][C:18]=1[C:19]([OH:21])=[O:20]

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 66743279HCID 66743279, compoundHCID 66743291HCID 66743291, compound

Product 1

HCID 7966502,4-dichloro-5-nitrobenzoic acidYield 72%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

2,4-Dichlorobenzoic acid 1-1 (1.0 g, 5.34 mmol) was added in one portion to a stirred solution of concentrated nitric acid (0.26 mL, 5.75 mmol) in concentrated sulphuric acid (7 mL). After 3 hours at room temperature the solution was poured onto ice. The resulting white solid was isolated via filtration and washed with H2O (×3). The white solid was then stirred with 1% Na2CO3 (aq) (20 mL) for 1 h at room temperature. Remaining insoluble material was filtered off and the resulting clear filtrate was concentrated to a pale yellow solid. Recrystallisation from H2O afforded the sodium salt as pale yellow crystals. (Note: the other minor product, sodium 2,4-dichloro-3-nitrobenzoate, remained in solution). The yellow crystals of sodium 2,4-dichloro-5-nitrobenzoate was dissolved in a minimum amount of H2O and acidified by the slow addition of concentrated HCl until a white precipitate formed. After isolation by filtration and washing with H2O 2,4-dichloro-5-nitrobenzoic acid 1-2 was obtained as a white solid (0.91 g, 72%). 1H NMR (400 MHz, CDCl3) δ7.73 (s, 1H), 8.60 (s, 1H).

Workup

  1. customformed
  2. filtrationAfter isolation by filtration
  3. washwashing with H2O 2,4-dichloro-5-nitrobenzoic acid 1-2

Sources & evidence

ORD record
ord-eb93559aa23b41d8bd57b416480795c3
Source dataset
uspto-grants-2014_11
Patent number
US08889695B2

Reaction notes

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