Synthesis
General procedure for the synthesis of methyl 4-hydroxy-5-methoxy-2-nitrobenzoate from methyl 4-benzyloxy-5-methoxy-2-nitrobenzoate: Methyl 2-nitro-4-benzyloxy-5-methoxybenzoate (4.1 mmol, 1.3 g) was dissolved in trifluoroacetic acid (8 mL), and the reaction was carried out at reflux for 1 hour. Upon completion of the reaction, trifluoroacetic acid was removed by decantation and the reaction mixture was extracted with water and ethyl acetate. The organic phases were combined, concentrated and purified by column chromatography to give 0.796 g methyl 2-nitro-4-hydroxy-5-methoxybenzoate in 86% yield.
References
[1] Patent: CN105884699, 2016, A. Location in patent: Paragraph 0064; 0065
[2] Patent: WO2016/148674, 2016, A1. Location in patent: Page/Page column 114
[3] Bioorganic and medicinal chemistry, 2004, vol. 12, # 16, p. 4337 - 4350
[4] Journal of Medicinal Chemistry, 2018, vol. 61, # 15, p. 6518 - 6545
[5] Bioorganic and Medicinal Chemistry Letters, 2002, vol. 12, # 20, p. 2989 - 2992
