A mixture of 5-bromo-thiophene Example 3, C2 (1.0 eq), Pd(PPh3)2Cl2 (0.025 eq), CuI (0.05 eq) and Et3N (28.7 eq) in THF (0.25 M) was degassed with a stream of Ar for 30 min. Trimethylsilylacetylene (1.5 eq) was added and the mixture was stirred O/N at RT. Evaporation of the solvent gave a residue which was purified by flash column chromatography on silica using 0-5% EtOAc/Petroleum ether to yield the desired compound as a yellow oil. 1H NMR (300 MHz, CDCl3, 300K) δ 7.83-7.78 (1H, m), 7.25 (1H, bs), 0.28 (9H, s).
