Synthesis
Step 1: 3-methyl-4-nitrobenzyl alcohol (1.0 eq.) was dissolved in dichloromethane, pyridinium chlorochromate (1.1 eq.) was added and the reaction mixture was stirred for 3 hours at room temperature. After completion of the reaction, the mixture was filtered through diatomaceous earth and the filtrate was concentrated under reduced pressure. The concentrated residue was adsorbed onto 100-200 mesh silica and purified by rapid column chromatography on silica gel, using a petroleum ether (60-80 °C) solution of 5% ethyl acetate as eluent to afford 3-methyl-4-nitrobenzaldehyde in milky white crystalline form in 93% yield. The product characterization data were as follows: 1H NMR (300 MHz, CDCl3) δ: 2.66 (s, 3H), 7.84-7.87 (m, 2H), 8.04-8.07 (d, J = 8.7 Hz, 1H), 10.12 (s, 1H); IR (KBr) 3104, 3079, 2981, 2857, 2743, 1702. 1607, 1518, 1383, 1361, 1308, 1226, 1153, 1008, 832, 735 cm-1.
References
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[2] Chemistry - A European Journal, 2015, vol. 21, # 9, p. 3567 - 3571
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[4] Farmaco, 1999, vol. 54, # 9, p. 579 - 583
[5] Patent: WO2007/24843, 2007, A2. Location in patent: Page/Page column 63-64
