Formaldehyde → HCID 13663046, compound

HRID 280600Notes

Reaction equation

HRID 280600 reaction equation
C([Li])CCC.Br[C:7]1[S:11][C:10]2[CH:12]=[C:13]([Br:16])[CH:14]=[CH:15][C:9]=2[C:8]=1[CH3:17].[CH2:18]=[O:19].O>CCCCCC.CCOCC>[Br:16][C:13]1[CH:14]=[CH:15][C:9]2[C:8]([CH3:17])=[C:7]([CH2:18][OH:19])[S:11][C:10]=2[CH:12]=1

Participants

7

Reactant 4

HCID 712FormaldehydeHCID 962WaterHCID 13540105HCID 13540105, compoundHCID 178418339Butyllithium

Product 1

HCID 13663046HCID 13663046, compoundYield 57.7%

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 8058HexaneSolvent

Procedure

A solution of n-butyl-lithium in hexane (13.2 ml of 1.55M solution) was added dropwise to a stirred solution of 2,6-dibromo-3-methylbenzo[b]thiophene (6.60 g) in dry ether (150 ml) at 0° under dry nitrogen and the mixture was stirred at 0° for 30 minutes. Paraformaldehyde (0.71 g) was then added portionwise and the mixture was stirred at 0° for 3 hours. Water was added and the layers were separated. The ether layer was washed with water, dried (Na2SO4) and evaporated to give an oil which was chromatographed on silica gel. Elution with chloroform first gave some impurity followed by pure product. Evaporation of the product-containing fractions gave a solid which was crystallised from ethyl acetate/petrol (b.p. 60°-80°) to give 6-bromo-2-hydroxymethyl-3-methylbenzo[b]thiophene (3.20 g), m.p. 95°-96°.

Workup

  1. stirringthe mixture was stirred at 0° for 3 hours
  2. customthe layers were separated
  3. washThe ether layer was washed with water
  4. dry with materialdried (Na2SO4)
  5. customevaporated
  6. customto give an oil which
  7. customwas chromatographed on silica gel
  8. washElution with chloroform
  9. customfirst gave some impurity
  10. customEvaporation of the product-containing fractions
  11. customgave a solid which
  12. customwas crystallised from ethyl acetate/petrol (b.p. 60°-80°)

Sources & evidence

ORD record
ord-c0922ede2d4a433299daf540034e0553
Source dataset
uspto-grants-1986_05
Patent number
US04590200

Reaction notes

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