2-Chloroethyl Benzenesulfonate → 5-(2-Chloroethoxy)benzo[b]thiophene-2-carboxylic acid methyl ester

HRID 648035Notes

Reaction equation

HRID 648035 reaction equation
[CH3:1][O:2][C:3]([C:5]1[S:9][C:8]2[CH:10]=[CH:11][C:12]([OH:14])=[CH:13][C:7]=2[CH:6]=1)=[O:4].C1(S(O[CH2:25][CH2:26][Cl:27])(=O)=O)C=CC=CC=1>[Na].CO>[CH3:1][O:2][C:3]([C:5]1[S:9][C:8]2[CH:10]=[CH:11][C:12]([O:14][CH2:25][CH2:26][Cl:27])=[CH:13][C:7]=2[CH:6]=1)=[O:4]

Participants

5

Reactant 2

HCID 136344852-Chloroethyl BenzenesulfonateHCID 13662999Methyl 5-hydroxybenzo[b]thiophene-2-carboxylate

Product 1

HCID 136630005-(2-Chloroethoxy)benzo[b]thiophene-2-carboxylic acid methyl esterYield 38.7%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 5360545SodiumSolvent

Procedure

5-Hydroxybenzo[b]thiophene-2-carboxylic acid methyl ester (1.47 g.) was dissolved in a solution of sodium (0.163 g.) in methanol (15 ml.) and 2-(benzenesulphonyloxy)ethyl chloride (1.57 g.) was added. The resulting solution was heated under reflux for 8 hours and then allowed to cool and stood overnight. The solution was then evaporated and the residue was partitioned between water and ether. The aqueous layer was separated and washed several times with ether. The combined organic layer and ethereal extracts were washed with water, dried (Na2SO4) and evaporated. The residue was chromatographed on silica gel. Elution with chloroform gave a solid which was crystallized from ethyl acetate/petrol (b.p. 60°-80°) to give 5-(2-chloroethoxy)benzo[b]-thiophene-2-carboxylic acid methyl ester, (0.74 g.), m.p. 116°-117° C.

Workup

  1. additionwas added
  2. temperatureThe resulting solution was heated
  3. temperatureunder reflux for 8 hours
  4. temperatureto cool
  5. customThe solution was then evaporated
  6. customthe residue was partitioned between water and ether
  7. customThe aqueous layer was separated
  8. washwashed several times with ether
  9. washThe combined organic layer and ethereal extracts were washed with water
  10. dry with materialdried (Na2SO4)
  11. customevaporated
  12. customThe residue was chromatographed on silica gel
  13. washElution with chloroform
  14. customgave a solid which
  15. customwas crystallized from ethyl acetate/petrol (b.p. 60°-80°)

Sources & evidence

ORD record
ord-263a9902110f4542aeb3a05a1f436f00
Source dataset
uspto-grants-1983_10
Patent number
US04410539

Reaction notes

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