Phosgene → 2,5-Dichloro-3-nitropyridine

HRID 327766Notes

Reaction equation

HRID 327766 reaction equation
C(Cl)([Cl:3])=O.[Cl:5][C:6]1[CH:7]=[C:8]([N+:13]([O-:15])=[O:14])[C:9](O)=[N:10][CH:11]=1>C1(C)C=CC=CC=1.CN(C)C=O>[Cl:3][C:9]1[C:8]([N+:13]([O-:15])=[O:14])=[CH:7][C:6]([Cl:5])=[CH:11][N:10]=1

Participants

5

Reactant 2

HCID 6371PhosgeneHCID 178526657HCID 178526657, compound

Product 1

HCID 80633312,5-Dichloro-3-nitropyridineYield 70%

Reagents, catalysts & solvents 2

HCID 1140TolueneSolventHCID 6228DimethylformamideSolvent

Procedure

75 g of phosgene are introduced at a temperature of 85°-95° C. over 1 hour into a mixture of 87.5 g of 5-chloro-2-hydroxy-3-nitropyridine in 500 ml of toluene and 3 ml of N,N-dimethylformamide. The reaction mixture is kept for 2 hours under reflux at 85°-95° C. and then allowed to cool to room temperature over a period of 18 hours. The reaction mixture is washed 3 times with water and the organic phase is dried over sodium sulfate and thereafter concentrated by evaporation. The crude product, obtained in the form of a brown oil, is crystallised from 200 ml of n-hexane, giving 67.5 g of 2,5-dichloro-3-nitropyridine (70% of theory) with a melting point of 38°-39° C.

Workup

  1. temperatureunder reflux at 85°-95° C.
  2. washThe reaction mixture is washed 3 times with water
  3. dry with materialthe organic phase is dried over sodium sulfate
  4. concentrationconcentrated by evaporation
  5. customThe crude product, obtained in the form of a brown oil
  6. customis crystallised from 200 ml of n-hexane

Sources & evidence

ORD record
ord-23ebee38aa744957a7b8a65e93a6d0ba
Source dataset
uspto-grants-1993_12
Patent number
US05274100

Reaction notes

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