Synthesis
Generic method: 4'-(3-methoxyphenyl)-2,2':6',2"-terpyridine (3-MeO-Phtpy), 4'-(2-methoxyphenyl)-2,2':6',2"-terpyridine (2-MeO-Phtpy) and 4'-(4-methoxyphenyl)-2,2':6',2"-terpyridine (4-MeO-Phtpy) The synthesis was carried out with reference to the method described in the literature [27-33]. The steps were as follows: 2-acetylpyridine (2.813 g, 23.2 mmol, 2 eq.) was added to a 50 mL ethanol solution dissolved in 2-methoxybenzaldehyde, 3-methoxybenzaldehyde or 4-methoxybenzaldehyde (11.6 mmol, 1 eq.). Subsequently, KOH pellets (46.5 mmol, 4 eq.) were added to this solution. The reaction mixture was stirred at room temperature for 10 minutes. NH3 (40 mL, 25% aqueous solution) was slowly added to the reaction mixture. After incubation at 37 °C for 24 h, 5 mL of 25% aqueous NH3 was added. The reaction mixture was cooled to -20 °C and the resulting white precipitate was separated by filtration and washed with cold ethanol. For further purification of each product, recrystallization was carried out using ethanol-H2O mixed solvent. After recrystallization, each product was recovered by filtration, washed sequentially with cold ethanol and petroleum ether, and finally dried under high vacuum for 24 h (Scheme 1).
References
[1] Applied Organometallic Chemistry, 2017, vol. 31, # 10,
[2] Applied Organometallic Chemistry, 2017, vol. 31, # 6,
[3] Chemistry - An Asian Journal, 2018, vol. 13, # 21, p. 3169 - 3172
[4] Chemistry Letters, 2005, vol. 34, # 5, p. 732 - 733
[5] Synthesis, 2005, # 18, p. 3045 - 3050
