Benzo(B)Thiophene → 1-Benzo[b]thien-2-yl-1-propanone

HRID 2183601Notes

Reaction equation

HRID 2183601 reaction equation
C([Li])CCC.[S:6]1[CH:10]=[CH:9][C:8]2[CH:11]=[CH:12][CH:13]=[CH:14][C:7]1=2.CON(C)[C:18](=[O:21])[CH2:19][CH3:20].[Cl-].[NH4+]>CCOCC.O.C(OCC)(=O)C>[S:6]1[C:10]([C:18](=[O:21])[CH2:19][CH3:20])=[CH:9][C:8]2[CH:11]=[CH:12][CH:13]=[CH:14][C:7]1=2

Participants

8

Reactant 4

HCID 7221Benzo(B)ThiopheneHCID 25517Ammonium ChlorideHCID 11344007N-Methoxy-N-methylpropionamideHCID 178418339Butyllithium

Product 1

HCID 224742131-Benzo[b]thien-2-yl-1-propanoneYield 80.1%

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 3283Diethyl EtherSolvent2×HCID 8857Ethyl AcetateSolvent

Conditions

Temperature
0 °C

Procedure

n-Butyllithium (1.6 M solution in hexanes; 28.9 ml) was added dropwise under nitrogen at 0° C. to a stirred solution of benzo[b]thiophene (6.21 g) in ether (90 ml), then the mixture was stirred 0° C. for 15 minutes and cooled to −70° C. A solution of N-methoxy-N-methylpropionamide (5.42 g) in ether (40 ml) was added over 10 minutes, then the mixture was allowed to warm to ambient temperature and was stirred at ambient temperature for 3.5 hours. The mixture was poured into saturated aqueous ammonium chloride solution (200 ml) and ethyl acetate (100 ml) and water (50 ml) were added. The organic phase was separated, washed with saturated aqueous sodium chloride solution (150 ml), dried (Na2SO4) and the solvents were removed in vacua. The residue was triturated with petroleum ether (b.p. 40-60° C.) (25 ml) and the resulting solid was collected by filtration and dried in vacuo to give 1-(benzo[b]thiophen-2-yl)propan-1-one (7.05 g) as a colourless solid, m.p. 79-81° C.

Workup

  1. temperaturecooled to −70° C
  2. temperatureto warm to ambient temperature
  3. stirringwas stirred at ambient temperature for 3.5 hours
  4. additionwere added
  5. customThe organic phase was separated
  6. washwashed with saturated aqueous sodium chloride solution (150 ml)
  7. dry with materialdried (Na2SO4)
  8. customthe solvents were removed in vacua
  9. customThe residue was triturated with petroleum ether (b.p. 40-60° C.) (25 ml)
  10. filtrationthe resulting solid was collected by filtration
  11. customdried in vacuo

Sources & evidence

ORD record
ord-fdcbc5da3ff945e88f44e5aa4bc764fe
Source dataset
uspto-grants-2005_05
Patent number
US06900216B2

Reaction notes

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