Synthesis
Step B: Synthesis of methyl 3-(bromomethyl)-2-nitrobenzoate; A mixture of methyl 3-methyl-2-nitrobenzoate (12.34 g, 63.23 mmol), benzoyl peroxide (0.920 g, 3.80 mmol) and N-bromosuccinimide (11.25 g, 63.21 mmol) in carbon tetrachloride (330 mL) was heated at refluxed for 12 h. The reaction was carried out under nitrogen protection. Upon completion of the reaction, the cooled mixture was diluted with dichloromethane (150 mL), treated with silica gel (30 g) and the solvent was removed under reduced pressure. The residue was purified by fast column chromatography on silica gel using ethyl acetate/hexane (15:85) as eluent to afford methyl 3-(bromomethyl)-2-nitrobenzoate (1B) as a light yellow solid (7.15 g, 41% yield). The product was confirmed by 1H NMR (CDCl3): δ 3.91 (s, 3H), 4.46 (s, 2H), 7.58 (t, 1H), 7.74 (dd, 1H), 7.96 (dd, 1H).
References
[1] Organic and Biomolecular Chemistry, 2014, vol. 12, # 30, p. 5629 - 5633
[2] Organic Process Research and Development, 2011, vol. 15, # 4, p. 831 - 840
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[4] Tetrahedron, 2004, vol. 60, # 10, p. 2235 - 2246
[5] Patent: WO2005/66136, 2005, A1. Location in patent: Page/Page column 88
