Thionyl Chloride → 5-Chlorothiophene-2-carbonyl Chloride

HRID 898648Notes

Reaction equation

HRID 898648 reaction equation
[Cl:1][C:2]1[S:6][C:5]([C:7]([OH:9])=O)=[CH:4][CH:3]=1.S(Cl)([Cl:12])=O>C1(C)C=CC=CC=1>[Cl:1][C:2]1[S:6][C:5]([C:7]([Cl:12])=[O:9])=[CH:4][CH:3]=1

Participants

4

Reactant 2

HCID 24386Thionyl ChlorideHCID 950485-Chloro-2-thiophenecarboxylic acid

Product 1

HCID 5892235-Chlorothiophene-2-carbonyl Chloride

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Conditions

Temperature
77.5 °C

Procedure

3.00 kg of 5-chlorothiophene-2-carboxylic acid (commercially available) are suspended in 8.48 kg of toluene and heated to 75 to 80° C. At this temperature, 2.63 kg of thionyl chloride are added dropwise over a period of 85 minutes, followed by stirring at 75 to 80° C. for 30 minutes and then at the reflux temperature until gas evolution ceases. After cooling, the reaction mixture is distilled under reduced pressure with gradually increasing internal temperature (up to a maximum of 60° C.) to remove excess thionyl chloride and toluene until an approximately 30% strength solution of the acid chloride in toluene is produced.

Workup

  1. temperatureAfter cooling
  2. distillationthe reaction mixture is distilled under reduced pressure
  3. temperaturewith gradually increasing internal temperature (up to a maximum of 60° C.)
  4. customto remove excess thionyl chloride and toluene until an approximately 30% strength solution of the acid chloride in toluene
  5. customis produced

Sources & evidence

ORD record
ord-9bbb7acf942e47beb5971732b1f39b0d
Source dataset
uspto-grants-2008_04
Patent number
US07351823B2

Reaction notes

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