2,8-di(pyridin-4-yl)dibenzo[b,d]thiophene synthesis

Yield:1610765-80-4 84%

Reaction Conditions:

with tetrakis(triphenylphosphine) palladium⁽⁰⁾;potassium carbonate in 1,4-dioxane;water; for 24 h;Inert atmosphere;Reflux;

Steps:

Synthesis of DPDBT

A mixture of 2,8-dibromodibenzo[b,d]thiophene (3.42 g, 10 mmol), Pd(PPh3)4 (0.580 g, 0.5 mmol), pyridine-4-boronic acid (2.93 g, 24 mmol), 1 mM K2CO3 (25 ml, 25 mmol) and 1,4-dioxane (100 ml) was refluxed under N₂ for 24 h. After cooling to room temperature, the mixture was extracted by CHCl₃ (3 ×100 ml). The combined organic layers were washed with brine, dried over MgSO4, and evaporated in vacuo. The residue was purified by silica gel column chromatography with EtOAc as eluent to give the target compound DPDBT as yellow solid (2.84 g, 84%). 1H NMR (500 MHz, DMSO-d6) d: 7.96 (d, 4 H, J 5.5 Hz),8.03 (d, 2 H, J 8.5 Hz), 8.22 (d, 2 H, J 8.5 Hz), 8.72 (d, 4 H, J 5.5 Hz), 9.11(s, 2 H). 13C NMR (125 MHz, DMSO-d6) d: 121.28, 121.82, 124.33, 126.25,134.42, 136.31, 140.60, 147.15, 150.74. MS (ESI-MS), m/z: 339.38 [M + H]+(calc. for C22H14N2S, m/z: 338.09).

References:

Zhang, Ming-Dao;Zheng, Bao-Hui;Jiao, Yan;Chen, Min-Dong [Mendeleev Communications,2014,vol. 24,# 3,p. 180 - 181]