Sulfuric Acid → 2,4,6-Trichloropyrimidine-5-carboxylic acid

HRID 2164696Notes

Reaction equation

HRID 2164696 reaction equation
[Cl:1][C:2]1[N:7]=[C:6]([Cl:8])[C:5]([CH:9]=[O:10])=[C:4]([Cl:11])[N:3]=1.S(=O)(=O)(O)[OH:13]>[O-2].[O-2].[O-2].[Cr+6]>[Cl:1][C:2]1[N:3]=[C:4]([Cl:11])[C:5]([C:9]([OH:13])=[O:10])=[C:6]([Cl:8])[N:7]=1

Participants

4

Reactant 2

HCID 1118Sulfuric AcidHCID 109327462,4,6-Trichloro-5-pyrimidinecarboxaldehyde

Product 1

HCID 200839572,4,6-Trichloropyrimidine-5-carboxylic acid

Reagents, catalysts & solvents 1

HCID 10219390chromium (VI) trioxideCatalyst

Procedure

To a solution of 63.3 g (0.3 mol) of 2,4,6-trichloro-5-formylpyrimidine in 300 ml of fuming sulfuric acid (SO3 content 25%) are added in flake form 24 g (0.24 mol) of chromium trioxide, and the mixture is stirred for 20 hours. The temperature rises within about one hour to 45°-50° C., and then falls again to room temperature (20°-25° C.). The reaction solution is poured into ice water, and the precipitate is filtered off and washed with a small amount of ice-water. The reaction product is dissolved in diethyl ether; the solution is then dried over sodium sulfate and subsequently evaporated to dryness. The yield is 55.4 g (81.2%) of 2,4,6-trichloropyrimidine-5-carboxylic acid, m.p. about 150° C. The melting point can be raised to 155°-157° C. by recrystallisation of the product from chloroform.

Workup

  1. waitThe temperature rises within about one hour to 45°-50° C.
  2. customfalls again to room temperature
  3. custom(20°-25° C.)
  4. filtrationthe precipitate is filtered off
  5. washwashed with a small amount of ice-water
  6. dissolutionThe reaction product is dissolved in diethyl ether
  7. dry with materialthe solution is then dried over sodium sulfate
  8. customsubsequently evaporated to dryness
  9. temperatureThe melting point can be raised to 155°-157° C. by recrystallisation of the product from chloroform

Sources & evidence

ORD record
ord-3e4c420a065e421db7f8ad3764e0c9ca
Source dataset
uspto-grants-1985_03
Patent number
US04507146

Reaction notes

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