Potassium Carbonate → 2-Methyl-5-methylsulfonyl-2,3-dihydro-1-benzofuran

HRID 518555Notes

Reaction equation

HRID 518555 reaction equation
Br[C:2]1[CH:3]=[CH:4][C:5]2[O:9][CH:8]([CH3:10])[CH2:7][C:6]=2[CH:11]=1.[CH3:12][S:13]([O:15][Na])=[O:14].N1CCC[C@H]1C(O)=O.C([O-])([O-])=O.[K+].[K+]>CS(C)=O.[Cu]I>[CH3:10][CH:8]1[CH2:7][C:6]2[CH:11]=[C:2]([S:13]([CH3:12])(=[O:15])=[O:14])[CH:3]=[CH:4][C:5]=2[O:9]1

Participants

7

Reactant 4

HCID 11430Potassium CarbonateHCID 145742L-ProlineHCID 133016015-Bromo-2-methyl-2,3-dihydro-1-benzofuranHCID 178504973HCID 178504973, compound

Product 1

HCID 1180220192-Methyl-5-methylsulfonyl-2,3-dihydro-1-benzofuranYield 50%

Reagents, catalysts & solvents 2

HCID 24350Copper(1+) iodide; Copper(I) iodide; Cuprous iodide; Cuprous iodide (CuI)CatalystHCID 679Dimethyl SulfoxideSolvent

Procedure

A mixture of 5-bromo-2-methyl-2,3-dihydro-1-benzofuran (1.0 g, 4.72 mmol), CH3SO2Na (730 mg, 7.08 mmol), L-proline (110 mg, 0.94 mmol), K2CO3 (120 mg, 0.94 mmol) and CuI (89 mg, 0.47 mmol) in DMSO (10 mL) was irradiated at 140° C. for 2 h under microwave. The mixture was extracted with EtOAc (2×30 mL). The combined organic layers were washed with brine (30 mL), dried over Na2SO4, filtered and concentrated to give the crude product that was purified by column chromatography on silica gel (PE/EA=2/1) to give the title compound (500 mg, 50%). 1H NMR (CDCl3, 400 MHz) δ 7.71-7.70 (m, 2H), 6.86-6.82 (m, 1H), 5.08-5.03 (m, 1H), 3.41-3.35 (m, 1H), 3.02 (s, 3H), 2.89-2.83 (m, 1H), 1.56 (d, J=6.4 Hz, 3H).

Workup

  1. customwas irradiated at 140° C. for 2 h under microwave
  2. extractionThe mixture was extracted with EtOAc (2×30 mL)
  3. washThe combined organic layers were washed with brine (30 mL)
  4. dry with materialdried over Na2SO4
  5. filtrationfiltered
  6. concentrationconcentrated
  7. customto give the crude product that
  8. customwas purified by column chromatography on silica gel (PE/EA=2/1)

Sources & evidence

ORD record
ord-4011f321c8704046bfcacf4598e51d74
Source dataset
uspto-grants-2015_08
Patent number
US09115114B2

Reaction notes

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