Tetrabutylammonium Fluoride → 4-Ethynyl-3-methyl-benzofuran-2-carboxylic acid ethyl ester

HRID 29289Notes

Reaction equation

HRID 29289 reaction equation
[CH2:1]([O:3][C:4]([C:6]1[O:7][C:8]2[CH:15]=[CH:14][CH:13]=[C:12]([C:16]#[C:17][Si](C)(C)C)[C:9]=2[C:10]=1[CH3:11])=[O:5])[CH3:2].[F-].C([N+](CCCC)(CCCC)CCCC)CCC>C1COCC1>[CH2:1]([O:3][C:4]([C:6]1[O:7][C:8]2[CH:15]=[CH:14][CH:13]=[C:12]([C:16]#[CH:17])[C:9]=2[C:10]=1[CH3:11])=[O:5])[CH3:2]

Participants

4

Reactant 2

HCID 2724141Tetrabutylammonium FluorideHCID 687154443-Methyl-4-trimethylsilanylethynyl-benzofuran-2-carboxylic acid ethyl ester

Product 1

HCID 860589154-Ethynyl-3-methyl-benzofuran-2-carboxylic acid ethyl esterYield 35%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To the product of Example 33, Step 1, 3-methyl-4-trimethylsilanylethynyl-benzofuran-2-carboxylic acid ethyl ester (1.5 g, 4.99 mmol, 1 eq), in THF (10 mL) under argon, was added tetrabutylammonium fluoride (1.0 M in THF, 6 mL, 5.99 mmol, 1.2 eq.) and the reaction was stirred at ambient temperature for 45 minutes. After work-up and flash column chromatography, 4-ethynyl-3-methyl-benzofuran-2-carboxylic acid ethyl ester was obtained in 35% yield. 1H NMR (400 MHz, DMSO-d6) δ ppm 1.4 (t, J=7.1 Hz, 3 H) 2.8 (s, 3 H) 4.4 (m, J=7.1, 7.1, 7.1 Hz, 2 H) 4.6 (s, 1 H) 7.5 (m, 2 H) 7.7 (dd, J=7.7, 1.4 Hz, 1 H).

Sources & evidence

ORD record
ord-cbf211a771d64922b783f8a172bf38d2
Source dataset
uspto-grants-2008_09
Patent number
US07420001B2

Reaction notes

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