Synthesis
General procedure for the synthesis of methyl 2-[(trimethylsilyl)ethynyl]benzoate from methyl 2-alkynylbenzoate:
1. Preparation of reaction system: Cesium fluoride (1.41 g, 9.30 mmol) was added to an acetonitrile/water (20 mL/5 mL) solution of methyl 2-[(trimethylsilyl)ethynyl]benzoate (540 mg, 2.32 mmol).
2. Reaction conditions: the reaction mixture was stirred at room temperature for 4 hours.
3. Post-treatment: After completion of the reaction, the reaction mixture was concentrated and the residue was partitioned with ethyl acetate (100 mL) and 0.2 N hydrochloric acid (30 mL). The aqueous layer was extracted with ethyl acetate (100 mL), the combined organic layers were washed with brine, dried over anhydrous magnesium sulfate, filtered and concentrated.
4. Purification: The residue was purified by column chromatography using 0 to 5% ethyl acetate/hexane as eluent to afford methyl 2-alkynylbenzoate (358 mg, 96% yield).
5. Characterization: GC/MS analysis showed a molecular ion peak m/z of 160.
References
[1] Tetrahedron Letters, 2003, vol. 44, # 46, p. 8525 - 8527
[2] Tetrahedron, 2007, vol. 63, # 40, p. 9979 - 9990
[3] Patent: WO2007/140174, 2007, A2. Location in patent: Page/Page column 32
[4] Organic Letters, 2010, vol. 12, # 16, p. 3651 - 3653
[5] Tetrahedron Letters, 2010, vol. 51, # 15, p. 2007 - 2009
