Diethyl Ether → Benzo[b]thiophene-2,3-dicarboxaldehyde

HRID 1073007Notes

Reaction equation

HRID 1073007 reaction equation
[CH:1]1[CH:6]=[C:5]2[C:7](Br)=[CH:8][S:9][C:4]2=[CH:3][CH:2]=1.CN([CH:14]=[O:15])C.C[CH2:17][O:18]CC>>[S:9]1[C:4]2[CH:3]=[CH:2][CH:1]=[CH:6][C:5]=2[C:7]([CH:17]=[O:18])=[C:8]1[CH:14]=[O:15]

Participants

4

Reactant 3

HCID 3283Diethyl Ether3×HCID 6228DimethylformamideHCID 123250Benzo(b)thiophene, 3-bromo-

Product 1

HCID 12202920Benzo[b]thiophene-2,3-dicarboxaldehydeYield 60%

Procedure

N-butyl lithium (150.6 ml, 241 mmol) is added dropwise to ether (100 ml) at −20° C. under N2. 3-Bromothianaphthene (10.5 ml, 80.3 mmol) is dissolved in ether (50 ml) and also added dropwise to the chilled solution, stirring cold for 0.5 h. DMF (16.3 ml, 210 mmol) is dissolved in ether (75 ml) and added dropwise, and the solution stirred an additional 15 h at −20° C. The reaction is quenched onto ice (300 g) in 10% H2SO4 (200 ml) and stirred until both layers turn yellow in color. The resulting slurry is filtered, and the cake is allowed to dry in the air stream, affording 1-benzothiophene-2,3-dicarbaldehyde (C180) as a yellow solid (60% yield). HRMS (FAB) calculated for C10H6O2S+H: 191.0167, found 191.0172 (M+H).

Workup

  1. additionalso added dropwise to the chilled solution
  2. additionadded dropwise
  3. stirringthe solution stirred an additional 15 h at −20° C
  4. customThe reaction is quenched onto ice (300 g) in 10% H2SO4 (200 ml)
  5. stirringstirred until both layers
  6. filtrationThe resulting slurry is filtered
  7. customto dry in the air stream

Sources & evidence

ORD record
ord-3a196151130a45a38695a5942968d031
Source dataset
uspto-grants-2005_06
Patent number
US06911543B2

Reaction notes

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