Trimethylsilyldiazomethane → Methyl 6-methyl-1-benzofuran-2-carboxylate

HRID 1773220Notes

Reaction equation

HRID 1773220 reaction equation
[CH3:1][C:2]1[CH:13]=[CH:12][C:5]2[CH:6]=[C:7]([C:9]([OH:11])=[O:10])[O:8][C:4]=2[CH:3]=1.[Si](C=[N+]=[N-])(C)(C)[CH3:15]>C1(C)C=CC=CC=1.CO>[CH3:1][C:2]1[CH:13]=[CH:12][C:5]2[CH:6]=[C:7]([C:9]([O:11][CH3:15])=[O:10])[O:8][C:4]=2[CH:3]=1

Participants

5

Reactant 2

HCID 167693TrimethylsilyldiazomethaneHCID 202609456-Methyl-1-benzofuran-2-carboxylic acid

Product 1

HCID 13662978Methyl 6-methyl-1-benzofuran-2-carboxylateYield 67.1%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 1140TolueneSolvent

Procedure

To a solution of 6-methylbenzofuran-2-carboxylic acid (11 g, 62.4 mmol) in 468 mL of toluene and 156 mL of MeOH was added 2N TMS-CHN2 (46.8 mL, 94 mmol) dropwise at room temperature. The reaction was stirred at room temperature for 6 hr. The reaction was then quenched by addition of acetic acid dropwise at 0° C. until the yellow color vanished, and gas evolution ceased. The reaction was concentrated under reduced pressure, and the residue was purified by silica gel flash chromatography, 100% Heptane-10% Ethyl Acetate/90% Heptane, to give methyl 6-methylbenzofuran-2-carboxylate (7.96 g). 1H NMR (400 MHz, DMSO-d6) δ 2.46 (s, 3H), 3.88 (s, 3H), 7.20 (dd, J=8.3, 1.0 Hz, 1H), 7.53 (s, 1H), 7.67 (d, J=8.1 Hz, 1H), 7.71 (d, J=1.0 Hz, 1H).

Workup

  1. customThe reaction was then quenched by addition of acetic acid dropwise at 0° C. until the yellow color
  2. concentrationThe reaction was concentrated under reduced pressure
  3. customthe residue was purified by silica gel flash chromatography, 100% Heptane-10% Ethyl Acetate/90% Heptane

Sources & evidence

ORD record
ord-6805d9d741f24b7fb426ca2ce3b1e31c
Source dataset
uspto-grants-2016_02
Patent number
US09255093B2

Reaction notes

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