4-chloro-2-(phenylethynyl)aniline

Synthesis

PdCl2(PPh3)2 (88 mg, 0.125 mmol), CuI (24 mg, 0.125 mmol) and anhydrous THF (5 mL) were added to an oven-dried two-necked round-bottomed flask under standard reaction conditions. To this suspension, 2-iodo-4-chloroaniline (5.47 mg, 2.5 mmol) and triethylamine (702 μL, 5.0 mmol) were added sequentially. The reaction mixture was degassed by argon bubbling for 15 min. Subsequently, phenylacetylene (300 μL, 2.75 mmol) was added and the reaction mixture was stirred at room temperature. The progress of the reaction was monitored by thin layer chromatography (TLC) and after complete consumption of 2-iodo-4-chloroaniline (about 2 h), the reaction mixture was filtered through diatomaceous earth. The filtrate was subjected to rotary evaporation to remove the solvent to give the crude product. The crude product was purified by column chromatography on silica gel (60-120 mesh) using ethyl acetate/hexane (1:9, v/v) as eluent, resulting in pure 4-chloro-2-(phenylalkynyl)aniline (400 mg, 83% yield).

References

[1] Angewandte Chemie - International Edition, 2013, vol. 52, # 45, p. 11835 - 11839
[2] Angew. Chem., 2013, vol. 125, # 45, p. 12051 - 12055,5
[3] Advanced Synthesis and Catalysis, 2010, vol. 352, # 18, p. 3355 - 3363
[4] Journal of the American Chemical Society, 2016, vol. 138, # 43, p. 14441 - 14448
[5] Tetrahedron Letters, 2014, vol. 55, # 40, p. 5495 - 5498