Hexamethylenetetramine → Benzo(b)thiophene-6-carboxaldehyde

HRID 1007945Notes

Reaction equation

HRID 1007945 reaction equation
[CH3:1][C:2]1[C:10]2[CH:9]=[CH:8][S:7][C:6]=2[CH:5]=[CH:4][CH:3]=1.[CH3:11][C:12]1[CH:13]=[CH:14][C:15]2[CH:19]=[CH:18][S:17][C:16]=2[CH:20]=1.C(OOC(=O)C1C=CC=CC=1)(=[O:28])C1C=CC=CC=1.BrN1C(=[O:45])CCC1=O.C1N2CN3CN(C2)CN1C3>C1C=CC=CC=1.O.C(O)(=O)C>[S:7]1[CH:8]=[CH:9][C:10]2[C:2]([CH:1]=[O:28])=[CH:3][CH:4]=[CH:5][C:6]1=2.[S:17]1[CH:18]=[CH:19][C:15]2[CH:14]=[CH:13][C:12]([CH:11]=[O:45])=[CH:20][C:16]1=2

Participants

10

Reactant 5

HCID 4101HexamethylenetetramineHCID 7187Benzoyl PeroxideHCID 357906-Methyl-1-benzothiopheneHCID 67184N-bromobutanimideHCID 84345Benzo(b)thiophene, 4-methyl-

Product 2

HCID 138740Benzo(b)thiophene-6-carboxaldehydeHCID 139857971-Benzothiophene-4-carbaldehyde

Reagents, catalysts & solvents 3

HCID 176Acetic AcidSolventHCID 241BenzeneSolventHCID 962WaterSolvent

Conditions

Temperature
50 °C

Procedure

In 350 mL of benzene is dissolved 23.53 g of a mixture of 4-methylbenzo[b]thiophene and 6-methylbenzo[b]thiophene, to which are added 0.77 g of benzoyl peroxide and 39.56 g of N-bromosuccinimide. The mixture thus formed is heated under reflux for 2 hours. After cooling the mixture to 50° C., 70 mL of acetic acid, 70 mL of water and 44.51 g of hexamethylenetetramine are added, and the mixture thus formed is heated under reflux for 2 hours. The solvent is distilled off under reduced pressure, the residue is mixed with water and ethyl acetate, and pH is adjusted to 7.5 with potassium carbonate. The organic layer is separated, washed with water and saturated aqueous solution of sodium chloride successively, and dried over anhydrous magnesium sulfate. The solvent is distilled off under reduced pressure, and the residue is purified by column chromatography (eluent: hexane:ethyl acetate=19:1 to 15:1). Thus, 5.24 g of benzo[b]thiophene-4-carboaldehyde, 5.09 g of benzo[b]thiophene-6-carboaldehyde and 6.71 g of mixture thereof are obtained as oily products.

Workup

  1. customThe mixture thus formed
  2. temperatureis heated
  3. temperatureunder reflux for 2 hours
  4. customthe mixture thus formed
  5. temperatureis heated
  6. temperatureunder reflux for 2 hours
  7. distillationThe solvent is distilled off under reduced pressure
  8. additionthe residue is mixed with water and ethyl acetate, and pH
  9. customThe organic layer is separated
  10. washwashed with water and saturated aqueous solution of sodium chloride successively
  11. dry with materialdried over anhydrous magnesium sulfate
  12. distillationThe solvent is distilled off under reduced pressure
  13. customthe residue is purified by column chromatography (eluent: hexane:ethyl acetate=19:1 to 15:1)

Sources & evidence

ORD record
ord-0538278b67334cb6b939d5215e9728cf
Source dataset
uspto-grants-2004_09
Patent number
US06797726B1

Reaction notes

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