Sulfuric Acid → 2,5-Difluoro-4-nitroaniline

HRID 2258618Notes

Reaction equation

HRID 2258618 reaction equation
CC1C=CC(S([NH:11][C:12]2[CH:17]=[C:16]([F:18])[C:15]([N+:19]([O-:21])=[O:20])=[CH:14][C:13]=2[F:22])(=O)=O)=CC=1.S(=O)(=O)(O)O>O>[F:22][C:13]1[CH:14]=[C:15]([N+:19]([O-:21])=[O:20])[C:16]([F:18])=[CH:17][C:12]=1[NH2:11]

Participants

4

Reactant 2

HCID 1118Sulfuric AcidHCID 22921537N-(4-methylphenylsulfonyl)-2,5-difluoro-4-nitroaniline

Product 1

HCID 2359302,5-Difluoro-4-nitroanilineYield 143.6%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
90 °C

Procedure

A stirred solution of 25.0 grams (0.076 mole) of N-(4-methylphenylsulfonyl)-2,5-difluoro-4-nitroaniline in 50 mL of water was cooled in an ice-water bath, and 150 mL of concentrated sulfuric acid was carefully added portionwise. Upon completion of the addition, the reaction mixture was heated to about 90° C., where it stirred for about four hours. The reaction mixture was then cooled and poured into wet ice. The resultant solid was collected by filtration and dried, yielding about 19.0 grams of 2,5-difluoro-4-nitroaniline. The NMR spectrum was consistent with the proposed structure.

Workup

  1. additionUpon completion of the addition
  2. temperatureThe reaction mixture was then cooled
  3. additionpoured into wet ice
  4. filtrationThe resultant solid was collected by filtration
  5. customdried

Sources & evidence

ORD record
ord-6e62b75be3694c899a13ab85019d3e76
Source dataset
uspto-grants-1997_08
Patent number
US05661108

Reaction notes

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