Synthesis
4.1.4 Synthesis of methyl 4-benzyloxy-5-methoxy-2-nitrobenzoate (12): intermediate 11 (10.1 g, 37 mmol) was suspended in acetic acid (100 mL) and 70% nitric acid (20 mL) was added slowly. Subsequently, the reaction mixture was heated to 50 °C and maintained at this temperature for 5 hours. Upon completion of the reaction, the mixture was cooled to room temperature and poured into ice water (500 mL). After stirring for 1 hour, the precipitate precipitated was collected by filtration, washed with water and dried to give nitro compound 12 as a white solid. Yield: 86%, melting point: 126-128°C.
References
[1] Patent: WO2016/148674, 2016, A1. Location in patent: Page/Page column 114
[2] Patent: US2009/76044, 2009, A1. Location in patent: Page/Page column 26
[3] Patent: US2017/95570, 2017, A1. Location in patent: Paragraph 0571; 0573
[4] Patent: US2014/235634, 2014, A1. Location in patent: Paragraph 0390; 0392
[5] Asian Journal of Chemistry, 2015, vol. 27, # 7, p. 2647 - 2650
