Hydrochloric Acid → Chloranil

HRID 1886206

Reaction equation

HRID 1886206 reaction equation
OO.Cl.[Cl-].[Mg+2].[Cl-].ClC1C(=O)C(Cl)=C(Cl)C(=O)C=1.[Cl:18][C:19]1[C:24]([OH:25])=[C:23]([Cl:26])[C:22]([Cl:27])=[C:21]([OH:28])[C:20]=1[Cl:29]>>[C:19]1([Cl:18])[C:24](=[O:25])[C:23]([Cl:26])=[C:22]([Cl:27])[C:21](=[O:28])[C:20]=1[Cl:29]

Participants

6

Reactant 5

HCID 313Hydrochloric AcidHCID 784Hydrogen PeroxideHCID 66603Tetrachloro-p-hydroquinoneHCID 69453Trichloro-1,4-benzoquinoneHCID 5360315Magnesium Chloride

Product 1

HCID 8371ChloranilYield 95%

Procedure

Re 1: A very large excess of hydrochloric acid (96 times the molar quantity) is required, and a very high salt load results due to the addition of 7.4 times the molar quantity of magnesium chloride. Furthermore, the prescribed temperature/time control during the addition of hydrogen peroxide cannot be maintained because of the high heat of reaction. A repeat of this process using only 30 times the molar quantity of hydrochloric acid, 3 times the molar quantity of magnesium chloride and more suitable temperature control gave a qualitatively poor chloranil (melting point 215°-220° C., yield 95% of theory) with trichloro-1,4-benzoquinone and tetrachlorohydroquinone as impurities.

Workup

  1. temperaturecannot be maintained because of the
  2. temperaturehigh heat of reaction

Sources & evidence

ORD record
ord-3e068acc8ab445feb70fb8a42944d900
Source dataset
uspto-grants-1992_09
Patent number
US05149850

Linked notes

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