Synthesis
General procedure for the synthesis of 5-methyl-2-nitrobenzaldehyde from 5-methyl-2-nitrobenzyl alcohol:
a) 5-methyl-2-nitrobenzyl alcohol (10 g, 59.88 mmol) was dissolved in dichloromethane (210 mL). Subsequently 3A molecular sieves (54 g) and pyridinium dichromate (22.53 g, 59.88 mmol) were added. The reaction mixture was stirred at room temperature for 6 hours. After completion of the reaction, the crude product was filtered through a short silica gel column and concentrated under reduced pressure. The residue was purified by fast column chromatography (silica gel, 10-20% ethyl acetate/hexane as eluent) to afford 7.84 g (79% yield) of the target compound 5-methyl-2-nitrobenzaldehyde as a colorless oil.1H NMR (CDCl3) δ 10.41 (m, 1H), 8.02 (m, 1H), 7.69 (s, 1H), 7.53 (d, 1H). 1H), 2.51 (s, 3H).
References
[1] Patent: US2004/10004, 2004, A1. Location in patent: Page 22
[2] Journal of Organic Chemistry, 1980, vol. 45, # 7, p. 1334 - 1336
[3] Indian Journal of Chemistry - Section B Organic and Medicinal Chemistry, 2001, vol. 40, # 5, p. 436 - 437
[4] Indian Journal of Chemistry - Section B Organic and Medicinal Chemistry, 2001, vol. 40, # 4, p. 329 - 330
[5] Bulletin of the Korean Chemical Society, 2011, vol. 32, # 12, p. 4309 - 4315
