Pyridinium chloride → 2-Acetyl-6,7-dichloro-5-hydroxybenzo[b]thiophene

HRID 485891Notes

Reaction equation

HRID 485891 reaction equation
[C:1]([C:4]1[S:8][C:7]2[C:9]([Cl:16])=[C:10]([Cl:15])[C:11]([O:13]C)=[CH:12][C:6]=2[CH:5]=1)(=[O:3])[CH3:2].Cl.N1C=CC=CC=1>>[C:1]([C:4]1[S:8][C:7]2[C:9]([Cl:16])=[C:10]([Cl:15])[C:11]([OH:13])=[CH:12][C:6]=2[CH:5]=1)(=[O:3])[CH3:2]

Participants

3

Reactant 2

HCID 10176127Pyridinium chlorideHCID 139528742-Acetyl-6,7-dichloro-5-methoxybenzo[b]thiophene

Product 1

HCID 132900362-Acetyl-6,7-dichloro-5-hydroxybenzo[b]thiopheneYield 56.6%

Procedure

A mixture of 9.5 g of 2-acetyl-6,7-dichloro-5-methoxybenzo[b]thiophene and 95 g of pyridine hydrochloride is heated at 185°-200° for four and one-half hours and allowed to cool. While still fluid in nature, the reaction mixture is poured onto ice and the resulting aqueous mixture is extracted three times with ethyl acetate. The organic fractions are combined, washed one time with water, two times with 2N hydrochloric acid, dried over anhydrous magnesium sulfate and evaporated. The residue is recrystallized from acetone-hexane to give 5.1 g of 2-acetyl-6,7-dichloro-5-hydroxybenzo[b]thiophene, mp 199°-201°.

Workup

  1. temperatureis heated at 185°-200° for four and one-half hours
  2. temperatureto cool
  3. additionWhile still fluid in nature, the reaction mixture is poured onto ice
  4. extractionthe resulting aqueous mixture is extracted three times with ethyl acetate
  5. washwashed one time with water, two times with 2N hydrochloric acid
  6. dry with materialdried over anhydrous magnesium sulfate
  7. customevaporated
  8. customThe residue is recrystallized from acetone-hexane

Sources & evidence

ORD record
ord-c7a0f9346d3647f984519c8b5d9e837f
Source dataset
uspto-grants-1985_08
Patent number
US04537976

Reaction notes

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