Synthesis
To a 1L three-necked round-bottomed flask was added 3-chlorophenol (33.6 g, 0.3 mol), anhydrous MgCl2 (85.7 g, 0.9 mmol), triethylamine (75.9 g, 0.75 mol) and anhydrous acetone (340 mL). The resulting solution was stirred at 25 °C for 30 min, followed by the addition of paraformaldehyde (45 g, 1.5 mol). The reaction mixture was heated to reflux for 5 h under nitrogen protection. When TLC monitoring showed complete consumption of the feedstock, the acetone was evaporated under reduced pressure. The residue was acidified to pH 3 with 10% hydrochloric acid solution and extracted with ethyl acetate (3 x 150 mL). The organic layers were combined, washed with water, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to give a brownish-red oil (18.1 g, 43.1% yield), which can be used directly in subsequent reactions without further purification (Byun et al., 2008; Uini and Lars, 1999).
References
[1] Applied Organometallic Chemistry, 2018, vol. 32, # 2,
[2] Drug Metabolism and Disposition, 2017, vol. 45, # 12, p. 1354 - 1363
[3] Organic and Biomolecular Chemistry, 2017, vol. 15, # 6, p. 1530 - 1536
[4] Organic Letters, 2015, vol. 17, # 23, p. 5824 - 5827
[5] Organic and Biomolecular Chemistry, 2016, vol. 14, # 30, p. 7268 - 7274
