Carbon Dioxide → 18781-38-9

HRID 280588Notes

Reaction equation

HRID 280588 reaction equation
Br[C:2]1[CH:3]=[CH:4][C:5]2[C:9]([CH3:10])=[CH:8][S:7][C:6]=2[CH:11]=1.CI.[Mg].[C:15](=[O:17])=[O:16]>CCOCC>[CH3:10][C:9]1[C:5]2[CH:4]=[CH:3][C:2]([C:15]([OH:17])=[O:16])=[CH:11][C:6]=2[S:7][CH:8]=1

Participants

6

Reactant 4

HCID 280Carbon DioxideHCID 6328Methyl iodideHCID 5462224MagnesiumHCID 13540107Benzo[b]thiophene, 6-bromo-3-methyl-

Product 1

HCID 1354011018781-38-9

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent2×

Procedure

A mixture of 6-bromo-3-methylbenzo[b]thiophene (16.8 g) and methyl iodide (23.8 g) was added dropwise to a stirred mixture of dry ether (150 ml) and magnesium (11.06 g) at such a rate that gentle reflux was maintained. When the addition was complete, the mixture was heated under reflux with stirring for 30 minutes, then cooled and poured onto a mixture of crushed solid carbon dioxide and ether. When all the carbon dioxide had evaporated, 2N hydrochloric acid (100 ml) was added and the mixture was shaken. The ether layer was separated and the aqueous layer was extracted with ether. The ether solutions were combined, dried (Na2SO4) and evaporated to give a solid which was crystallized from ethyl acetate to give 3-methylbenzo[b]thiophene-6-carboxylic acid (7.71 g), m.p. 230°-232° C.

Workup

  1. temperaturethat gentle reflux
  2. temperaturewas maintained
  3. additionWhen the addition
  4. temperaturethe mixture was heated
  5. temperatureunder reflux
  6. temperaturecooled
  7. customWhen all the carbon dioxide had evaporated
  8. addition2N hydrochloric acid (100 ml) was added
  9. stirringthe mixture was shaken
  10. customThe ether layer was separated
  11. extractionthe aqueous layer was extracted with ether
  12. dry with materialdried (Na2SO4)
  13. customevaporated
  14. customto give a solid which
  15. customwas crystallized from ethyl acetate

Sources & evidence

ORD record
ord-c845e38820a2419dbae83c7d93b09c0c
Source dataset
uspto-grants-1986_05
Patent number
US04590200

Reaction notes

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