Hydrochloric Acid → 8-Chloro-2,3-dihydro-3-(hydroxymethylene)-4H-1-benzothiopyran-4-one

HRID 2308938Notes

Reaction equation

HRID 2308938 reaction equation
[Cl:1][C:2]1[C:11]2[S:10][CH2:9][CH2:8][C:7](=[O:12])[C:6]=2[CH:5]=[CH:4][CH:3]=1.[CH:13](OCC)=[O:14].C[O-].[Na+].Cl>C1C=CC=CC=1>[Cl:1][C:2]1[C:11]2[S:10][CH2:9][C:8](=[CH:13][OH:14])[C:7](=[O:12])[C:6]=2[CH:5]=[CH:4][CH:3]=1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 8025Ethyl formateHCID 10942334Sodium MethoxideHCID 12283929HCID 12283929, compound

Product 1

HCID 703524958-Chloro-2,3-dihydro-3-(hydroxymethylene)-4H-1-benzothiopyran-4-oneYield 88.8%

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent2×

Procedure

A solution of 8-chloro-2,3-dihydro-4H-1-benzothiopyran-4-one (10 g) in benzene (125 ml) was added dropwise to a mixture of ethyl formate (7.46 g) and sodium methoxide (5.44 g) in benzene (40 ml) with ice cooling and stirring over a period of 10 minutes. After being stirred for 1 hour at room temperature, 10% hydrochloric acid was added to the reaction mixture. The aqueous layer was separated and extracted with ethyl acetate. The combined organic layers were washed with water, dried over magnesium sulfate, and evaporated in vacuo. The residue was recrystallized from a mixture of ethyl acetate and n-hexane to give 8-chloro-2,3-dihydro-3-hydroxymethylene-4H-1-benzothiopyran-4-one (10.13 g).

Workup

  1. stirringAfter being stirred for 1 hour at room temperature
  2. customThe aqueous layer was separated
  3. extractionextracted with ethyl acetate
  4. washThe combined organic layers were washed with water
  5. dry with materialdried over magnesium sulfate
  6. customevaporated in vacuo
  7. customThe residue was recrystallized from a mixture of ethyl acetate and n-hexane

Sources & evidence

ORD record
ord-3e53ee0104c241e1bf1b64247c7cd6d8
Source dataset
uspto-grants-1987_09
Patent number
US04692444

Reaction notes

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