Synthesis
GENERAL METHOD: 4-Methoxybenzoyl hydrazine (0.73 mmol) was dissolved in 10 mL of anhydrous ethanol, and triethyl orthoformate (0.81 mmol) and ammonium chloride (0.219 mmol) were added sequentially. The reaction mixture was stirred and heated to reflux for a controlled reaction time of 0.5 to 18 hours. Upon completion of the reaction, the mixture was cooled to room temperature and subsequently concentrated under vacuum. The crude product was purified by one of two methods: (1) making a slurry in a solvent mixture of hexane and ether (3:1, v/v), filtering it and washing it with deionized water; and (2) purification by column chromatography.
References
[1] Tetrahedron Letters, 2014, vol. 55, # 50, p. 6776 - 6778
[2] Organic Letters, 2018, vol. 20, # 19, p. 6027 - 6032
[3] Angewandte Chemie - International Edition, 2011, vol. 50, # 48, p. 11511 - 11515
[4] Journal of the American Chemical Society, 2016, vol. 138, # 38, p. 12605 - 12614
[5] European Journal of Medicinal Chemistry, 2013, vol. 65, p. 276 - 283
