Tributyl(prop-1-yn-1-yl)stannane → 3-Methyl-4-prop-1-ynyl-benzofuran-2-carboxylic acid ethyl ester

HRID 29285Notes

Reaction equation

HRID 29285 reaction equation
[CH2:1]([O:3][C:4]([C:6]1[O:7][C:8]2[CH:15]=[CH:14][CH:13]=[C:12](OS(C(F)(F)F)(=O)=O)[C:9]=2[C:10]=1[CH3:11])=[O:5])[CH3:2].[CH2:24]([Sn](CCCC)(CCCC)C#CC)[CH2:25][CH2:26]C.C(OCC)(=O)C.CCCCCC>C1(C)C=CC=CC=1.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[CH2:1]([O:3][C:4]([C:6]1[O:7][C:8]2[CH:15]=[CH:14][CH:13]=[C:12]([C:24]#[C:25][CH3:26])[C:9]=2[C:10]=1[CH3:11])=[O:5])[CH3:2]

Participants

6

Reactant 3

HCID 2733165Tributyl(prop-1-yn-1-yl)stannaneHCID 21226206Ethyl acetate hexaneHCID 865990263-Methyl-4-trifluoromethanesulfonyloxy-benzofuran-2-carboxylic acid ethyl ester2×

Product 1

HCID 687125663-Methyl-4-prop-1-ynyl-benzofuran-2-carboxylic acid ethyl esterYield 14%

Reagents, catalysts & solvents 2

HCID 178418397HCID 178418397, compoundCatalystHCID 1140TolueneSolvent

Procedure

To 3-methyl-4-trifluoromethanesulfonyloxy-benzofuran-2-carboxylic acid ethyl ester (550 mg, 1.6 mmol, 1 eq), the product of Example 20, Step 1, in 5 mL of toluene under nitrogen was added 60 mg of Pd(PPh3)4 (0.05 mmol, 0.03 eq) and tributyl-prop-1-ynyl-stannane (0.55 mL, 1.8 mmol, 1.13 eq). The resulting reaction mixture was heated to reflux for 18 h. After work up and column chromatography (3% ethyl acetate/hexane), 3-methyl-4-prop-1-ynyl-benzofuran-2-carboxylic acid ethyl ester was obtained in 14% yield (56 mg). 1H NMR (400 MHz, CDCl3) δ ppm 1.4 (t, J=7.1 Hz, 3 H) 2.1 (s, 3 H) 2.8 (s, 3 H) 4.5 (q, J=7.1 Hz, 2 H) 7.3 (m, 2 H) 7.5 (dd, J=7.6, 1.8 Hz, 1 H).

Workup

  1. customThe resulting reaction mixture
  2. temperaturewas heated
  3. temperatureto reflux for 18 h

Sources & evidence

ORD record
ord-8e92d4e01b68417398f79cfc88a53aaa
Source dataset
uspto-grants-2008_09
Patent number
US07420001B2

Reaction notes

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