Sodium Chloride → 6-Methoxy-2-methylbenzofuran

HRID 1825075Notes

Reaction equation

HRID 1825075 reaction equation
I[C:2]1[CH:7]=[CH:6][C:5]([O:8][CH3:9])=[CH:4][C:3]=1[OH:10].CN(C)C(N(C)C)=N.[CH:19]#[C:20][CH3:21].[Na+].[Cl-]>CN(C=O)C>[CH3:9][O:8][C:5]1[CH:6]=[CH:7][C:2]2[CH:19]=[C:20]([CH3:21])[O:10][C:3]=2[CH:4]=1

Participants

6

Reactant 4

HCID 5234Sodium ChlorideHCID 6335PropyneHCID 664601,1,3,3-TetramethylguanidineHCID 114140152-Iodo-5-methoxyphenol

Product 1

HCID 130130736-Methoxy-2-methylbenzofuranYield 74%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

A pressure tube was charged with a stir bar 2-Iodo-5-methoxyphenol (500 mg, 2.0 mmol) (prepared according to Heterocycles 45, (6), 1997, 1137), Cl2Pd(PPh3)2 (70 mg, 0.1 mmol), Cul (19 mg, 0.1 mmol), 1,1,3,3-Tetramethylguanidine (2.5 ml, 20.0 mmol) and DMF (10 ml), then cooled to −78° while propyne gas was condensed. The tube was sealed and allowed to warm to room temperature. After 18 hours, the contents of the tube were poured into sat NaCl solution and extracted with EtOAc (2×). The combined organic layers were washed with brine (3×), dried (MgSO4) and concentrated under reduced pressure. The residue was flash chromatographed on silica gel eluting 3:1 (hexanes/ethyl acetate) to give 239 mg (74%) of an amber liquid. 1H NMR (DMSO-d6) δ 7.31 (1H, d, J=8.3 Hz), 6.95 (1H, d, J=2.2 Hz), 6.80 (1H, dd, J=2.2, 8.3 Hz), 6.27 (1H, s), 3.85 (3H, s), 2.40 (3H, s). Anal. Calcd for C10H10O2.0.05 hexanes: C, 74.30; H, 6.48. Found: C, 74.63; H, 6.48.

Workup

  1. customcondensed
  2. customThe tube was sealed
  3. additionthe contents of the tube were poured
  4. extractionextracted with EtOAc (2×)
  5. washThe combined organic layers were washed with brine (3×)
  6. dry with materialdried (MgSO4)
  7. concentrationconcentrated under reduced pressure
  8. customchromatographed on silica gel eluting 3:1 (hexanes/ethyl acetate)

Sources & evidence

ORD record
ord-fd86f7dbf50c46f2bb47323665e08e78
Source dataset
uspto-grants-2006_05
Patent number
US07045528B2

Reaction notes

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