Dimethylformamide → 4,4-dimethyl-3,4-dihydro-2H-thiochromene-6-carbaldehyde

HRID 861769Notes

Reaction equation

HRID 861769 reaction equation
[CH3:1][C:2]1([CH3:13])[C:11]2[C:6](=[CH:7][CH:8]=[C:9](Br)[CH:10]=2)[S:5][CH2:4][CH2:3]1.C([Li])CCC.CN([CH:22]=[O:23])C.[Cl-].[NH4+]>C1COCC1>[CH3:1][C:2]1([CH3:13])[C:11]2[C:6](=[CH:7][CH:8]=[C:9]([CH:22]=[O:23])[CH:10]=2)[S:5][CH2:4][CH2:3]1

Participants

6

Reactant 4

HCID 6228DimethylformamideHCID 25517Ammonium ChlorideHCID 98165546-Bromo-4,4-dimethylthiochromanHCID 178418339Butyllithium

Product 1

HCID 152843084,4-dimethyl-3,4-dihydro-2H-thiochromene-6-carbaldehyde

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

9.4 g (36.6 mmol) of 4,4-dimethyl-6-bromothiochroman and 100 ml of THF were introduced into a three-necked flask under a stream of nitrogen. 16.1 ml of an n-butyllithium solution (2.5M in hexane) were added dropwise at -78° C. and stirring was carried out for 30 min. 2.7 ml (38.4 mmol) of DMF were then added dropwise and the mixture was permitted to heat to room temperature. The reaction mixture was poured into an aqueous ammonium chloride solution and extracted with ethyl ether. The organic phase was separated by settling, dried over magnesium sulfate and evaporated. The residue obtained was purified by chromatography on a silica column eluted with a mixture of dichloromethane and hexane (50/50). After evaporating the solvents, 6.1 g (81%) of the expected aldehyde were recovered in the form of a yellow oil.

Workup

  1. extractionextracted with ethyl ether
  2. customThe organic phase was separated
  3. dry with materialdried over magnesium sulfate
  4. customevaporated
  5. customThe residue obtained
  6. customwas purified by chromatography on a silica column
  7. washeluted with a mixture of dichloromethane and hexane (50/50)
  8. customAfter evaporating the solvents, 6.1 g (81%) of the expected aldehyde
  9. customwere recovered in the form of a yellow oil

Sources & evidence

ORD record
ord-0fb65f79a0b64d22bab1bd97222975ca
Source dataset
uspto-grants-1998_02
Patent number
US05716624

Reaction notes

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