Trimethylsilylacetylene → 3,4-Dimethoxy-5-((trimethylsilyl)ethynyl)benzoic acid

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Reaction Steps

To a stirred solution of 3-iodo-4,5-dimethoxybenzoic acid (6.16 g, 20.0 mmol) in a mixture of Et3N (40 mL) and benzene (40 mL) at room temperature, was added CuI (380 mg, 2 mmol), Pd(PPh3)4 (462 mg, 0.4 mmol) and (trimethylsilyl)acetylene (3.4 mL, 24 mmol). After stirring for 3 days at room temperature, the solvent was removed in vacuo, the residue was diluted with 1 N HCl aqueous solution (300 mL) and then extracted with EtOAc (3×100 mL). The combined organic layer was washed with brine (300 mL), dried over Na2SO4 and concentrated in vacuo to give 3,4-dimethoxy-5-(trimethylsilanylethynyl)benzoic acid (5.6 g). The product was used without further purification.

Provenance & Evidence