Acetone → 4-(2,3-Dihydro-1-benzofuran-5-yl)but-3-en-2-one

HRID 431789Notes

Reaction equation

HRID 431789 reaction equation
[O:1]1[CH2:5][CH2:4][C:3]2[CH:6]=[C:7]([CH:10]=O)[CH:8]=[CH:9][C:2]1=2.[CH3:12][C:13]([CH3:15])=[O:14].[OH-].[Na+].Cl>C(Cl)Cl.O>[O:1]1[C:2]2[CH:9]=[CH:8][C:7](/[CH:10]=[CH:12]/[C:13](=[O:14])[CH3:15])=[CH:6][C:3]=2[CH2:4][CH2:5]1

Participants

7

Reactant 4

HCID 180AcetoneHCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 7359012,3-Dihydrobenzofuran-5-carboxaldehyde

Product 1

HCID 225923854-(2,3-Dihydro-1-benzofuran-5-yl)but-3-en-2-oneYield 84%

Reagents, catalysts & solvents 2

HCID 962WaterSolvent2×HCID 6344DichloromethaneSolvent

Procedure

2,3-Dihydrobenzo[b]furan-5-carboxaldehyde (Aldrich Chemicals) (2 g, 13.5 mmol), acetone (2.73 ml, 37.1 mmol), water (1.35 ml) and 10% NaOH (aq.) (0.34 ml) were added together and the whole stirred at room temperature for 16 h. The yellow solid was redissolved in approx. 15 ml DCM and 2N HCl added to achieve a solution of pH 2. Water (10 ml) was added and the organic layer was extracted with DCM (2×20 ml). The aqueous layers were separated, and re-extracted with DCM (2×15 ml). The combined organics were dried (MgSO4) and concentrated in vacuo to a yellow solid which was purified by column chromatography using 15-30% EtOAc in pentane as eluant to provide the title product (2.13 g, 84%); 1HNMR (400 MHz, CDCl3) δ: 2.3 (s, 3H), 3.2 (t, 2H), 4.6 (t, 2H), 6.5 (d, 1H), 6.75 (d, 1H), 7.3 (d, 1H), 7.4 (s, 1H), 7.45 (d, 1H); LRMS: M+H, 189. (ES+).

Workup

  1. extractionthe organic layer was extracted with DCM (2×20 ml)
  2. customThe aqueous layers were separated
  3. extractionre-extracted with DCM (2×15 ml)
  4. dry with materialThe combined organics were dried (MgSO4)
  5. concentrationconcentrated in vacuo to a yellow solid which
  6. customwas purified by column chromatography

Sources & evidence

ORD record
ord-cd34349262ad4c7a9cbcde7d885efb28
Source dataset
uspto-grants-2003_12
Patent number
US06660756B2

Reaction notes

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