Dimethylformamide → 5,6-dichloropyridine-3-carbonyl Chloride

HRID 2369448Notes

Reaction equation

HRID 2369448 reaction equation
[Cl:1][C:2]1[C:3]([Cl:11])=[N:4][CH:5]=[C:6]([CH:10]=1)[C:7](O)=[O:8].CN(C=O)C.S(Cl)([Cl:19])=O.C(=O)(O)[O-].[Na+]>ClC(Cl)C>[Cl:1][C:2]1[C:3]([Cl:11])=[N:4][CH:5]=[C:6]([CH:10]=1)[C:7]([Cl:19])=[O:8]

Participants

6

Reactant 4

HCID 6228DimethylformamideHCID 24386Thionyl ChlorideHCID 2479875,6-Dichloronicotinic acidHCID 516892Sodium Bicarbonate

Product 1

HCID 27821565,6-dichloropyridine-3-carbonyl Chloride

Reagents, catalysts & solvents 1

HCID 63651,1-DichloroethaneSolvent

Conditions

Temperature
75 °C

Procedure

To a well stirred suspension of 5,6-dichloronicotinic acid 5 (600 g, 3.125 mole, Sigma-Aldrich) and DMF (20.0 mL) in dichloroethane (1.2 L) was added drop wise with stirring thionyl chloride (743.56 g, 6.25 mole). The reaction mixture was set up for heating with reflux, fitted with a gas trap filled with saturated aqueous sodium bicarbonate and heated at a temperature of 75° C. until the reaction mixture formed a clear solution, about 3 h. LC/MS of a sample quenched in methanol showed only the presence of the methyl ester. The reaction mixture was cooled to a temperature of about 25° C. and concentrated under reduced pressure to provide 5,6-dichloronicotinoyl chloride 6 as a thick paste.

Workup

  1. temperaturefor heating
  2. temperaturewith reflux
  3. customfitted with a gas trap
  4. customformed a clear solution, about 3 h
  5. customLC/MS of a sample quenched in methanol
  6. temperatureThe reaction mixture was cooled to a temperature of about 25° C.
  7. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-1bf25c36dcc54b1f81d1ae6ee2dd8034
Source dataset
uspto-grants-2014_04
Patent number
US08703962B2

Reaction notes

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