Hydrochloric Acid → 3-Chlorothiophene-2-carboxylic acid

HRID 436830

Reaction equation

HRID 436830 reaction equation
O=P12OP3(OP(OP(O3)(O1)=O)(=O)O2)=O.P(Cl)(Cl)(Cl)(Cl)Cl.O[C:22]1[CH:26]=[CH:25][S:24][C:23]=1[C:27]([O:29]C)=[O:28].[ClH:31]>C(Cl)(Cl)(Cl)Cl>[Cl:31][C:22]1[CH:26]=[CH:25][S:24][C:23]=1[C:27]([OH:29])=[O:28]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 14812Phosphorus oxide (P4O10)HCID 24819Phosphorus pentachloride3×HCID 5811273-Hydroxy-thiophene-2-carboxylic acid methyl ester

Product 1

HCID 7012693-Chlorothiophene-2-carboxylic acid

Reagents, catalysts & solvents 1

HCID 5943Carbon TetrachlorideSolvent2×

Procedure

14.5 liters of absolute carbon tetrachloride (refluxed for 1 hour with 500 g of P2O5 and then distilled) is placed in a 25 liter apparatus equipped with stirrer, dropping funnel, drainage cock and reflux condenser with gas outlet; while stirring, 2,200 g (10.05 moles) of PCl5 is added. Upon refluxing the mixture the PCl5 goes into solution (a small amount of PCl5 settles in the drainage cock). 660 g (4.18 moles) of methyl 3-hydroxythiophene-2-carboxylate (prepared as described in German Pat. No. 1,020,641) dissolved in 2 liters of absolute carbon tetrachloride is allowed to flow at a just continuous rate over a period of 4 hours into the boiling solution (vigorous evolution of HCl).

Workup

  1. distillationdistilled)
  2. customequipped with stirrer
  3. temperaturedrainage cock and reflux condenser with gas outlet

Sources & evidence

ORD record
ord-81e26392fbf14f8e949829d1d75bbb8e
Source dataset
uspto-grants-1977_06
Patent number
US04028373

Linked notes

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