Synthesis
The general procedure for the synthesis of 3-methoxy-4-(1,3-oxazolyl)aniline from 5-(2-methoxy-4-nitrophenyl)oxazole was as follows: 5-(2-methoxy-4-nitrophenyl)oxazole (10 g, 45.4 mmol) was dissolved in a solvent mixture of tetrahydrofuran (185 ml) and ethanol (37 ml). Palladium-carbon catalyst (Pd/C, 2.0 g, 1.88 mmol) was added to the reaction system under argon protection. After displacing the gas in the reaction system with hydrogen, the reaction mixture was stirred vigorously at room temperature overnight. Upon completion of the reaction, the catalyst was removed by filtration and washed with tetrahydrofuran and ethanol. The filtrate was concentrated to give an oil, which was allowed to stand for several hours and then crystallized. 3-Methoxy-4-(1,3-oxazole)aniline was finally obtained as a yellow solid (8.54 g, 97% yield); mass spectrum (ISN) m/z = 191.08 [(M + H)+].
References
[1] Patent: WO2014/79850, 2014, A1. Location in patent: Page/Page column 53; 54
[2] Bioorganic and Medicinal Chemistry Letters, 2002, vol. 12, # 9, p. 1323 - 1326
[3] Bioorganic and Medicinal Chemistry Letters, 2002, vol. 12, # 20, p. 2879 - 2882
[4] Heterocycles, 2006, vol. 68, # 1, p. 167 - 173
[5] Patent: WO2004/214, 2003, A2. Location in patent: Page 42
