Dichloromethane → 5-Bromothiophene-2,3-dicarbaldehyde

HRID 61931Notes

Reaction equation

HRID 61931 reaction equation
BrBr.S1C=CC(C=O)=C1C=O.Br[C:13]1[C:14]([CH:21]=[O:22])=[C:15]([CH:19]=[O:20])[S:16][C:17]=1[Br:18].C(Cl)Cl>C(O)(=O)C>[Br:18][C:17]1[S:16][C:15]([CH:19]=[O:20])=[C:14]([CH:21]=[O:22])[CH:13]=1

Participants

6

Reactant 4

HCID 6344DichloromethaneHCID 24408BromineHCID 573752Thiophene-2,3-dicarbaldehydeHCID 118484293HCID 118484293, compound2×

Product 1

HCID 848194675-Bromothiophene-2,3-dicarbaldehyde

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Conditions

Temperature
70 °C

Procedure

Bromine (1.2 mL, 7.5 mmol) was added drop wise to a solution of 2,3-thiophenedicarboxaldehyde (1.0 g, 7.1 mmol) in 20 mL of glacial acetic acid. The reaction mixture was stirred overnight at 70° C. and then excess bromine was quenched with a saturated solution of Na2S2O3. The organic layer was extracted with CH2Cl2, dried over Na2SO4 and volatiles were removed in vacuo to obtain a mixture of 1 and 4,5-dibromo-2,3-thiophenedicarboxaldehyde 2 as a brown solid (30:65 by 1H NMR spectroscopy). Spectroscopically pure compound was isolated by column chromatography using silica gel as stationary phase and a 4:1 mixture of CH2Cl2:hexanes. 1H NMR (500 MHz, CDCl3): δ 10.37 (s, 1H), 10.26 (s, 1H), 7.59 (s, 1H). 1H NMR data for 4,5-dibromo-2,3-thiophenedicarboxaldehyde (500 MHz, CDCl3): δ 9.81 (s, 1H), 7.36 (s, 1H).

Workup

  1. customexcess bromine was quenched with a saturated solution of Na2S2O3
  2. extractionThe organic layer was extracted with CH2Cl2
  3. dry with materialdried over Na2SO4 and volatiles
  4. customwere removed in vacuo
  5. customto obtain
  6. customSpectroscopically pure compound was isolated by column chromatography

Sources & evidence

ORD record
ord-3094f0c376ee4927b71ab4bcbf9cb4f4
Source dataset
uspto-grants-2016_09
Patent number
US09444060B2

Reaction notes

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