A mixture of the corresponding 2-Bromo-6-(4-methoxy-phenyl)-4-(2-trimethylsilanyl-ethoxymethyl)-4,7-dihydro-1-thia-4,5-diaza-cyclopenta[a]pentalene (0.5 g, 0.1 mmol), 2-(3,4-Difluoro-phenyl)-4,4,5,5-tetramethyl-[1,3,2]dioxaborolane (0.24 g, 0.1 mmol), Na2CO3 (2 M, 2.45 mL), and Pd(PPh3)2Cl2 (9.7 mg, 0.084 mmol) in toluene/ethanol (1:1, 8.0 mL) was heated at 100° C. for 8 hr. The solution was cooled to room temperature and extracted with ethyl acetate. The target product was purified by gravity column chromatography (20% EtOAc in hexane) to give 2-(3,4-Difluoro-phenyl)-6-(4-methoxy-phenyl)-4-(2-trimethylsilanyl-ethoxymethyl)-4,7-dihydro-1-thia-4,5-diaza-cyclopenta[a]pentalene as orange solid in 65% yield.
