Trimethylsilylacetylene → Methyl 4-trimethylsilylethynylbenzoate

Participants

Reaction Conditions

Reaction Steps

To a cooled solution (−78° C.) of (trimethylsilyl)acetylene (4.2 mL, 30 mmol) in THF (25 mL) is added dropwise (2.5M) n-butyllithium (11.6 mL, 29 mmol) and stirred for 30 min followed by slow addition of (0.5M) zinc chloride (58 mL, 29 mmol). The resulting solution is allowed to warm to 20° C. followed by addition of 4-iodo-benzoic acid methyl ester (5.24 g, 20 mmol) (reference example 48) and tetrakis(triphenylphosphine)palladium(0) (1.16 g, 1 mmol) in THF (10 mL). The resulting mixture is heated to 55° C. and stirred for 2 hours then cooled to 20° C. The reaction mixture is diluted with ethyl acetate, washed with sat.NH4Cl soln, water and brine, dried over MgSO4 and concentrated to give 4.65 g of title compound. 1H NMR (CDCl3) δ 0.26 (s, 2H), 3.91 (s, 3H), 7.52 (d, J=8 Hz, 2H), 7.97 (d, J=8 Hz, 2H). MS (EI) m/z 232 (M+).

Provenance & Evidence