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

HRID 370982Notes

Reaction equation

HRID 370982 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-86b90becfdb043a689b18021bfb42e8c
Source dataset
uspto-grants-1985_07
Patent number
US04528399

Reaction notes

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