850449-93-3

Step 3: Methyl 2-(2-methyl-5-nitrophenyl)acetate (Ex. 4b, 3.68 g, 16.5 mmol) was dissolved in anhydrous ethanol (60 mL). To this solution was added 10% palladium carbon catalyst (0.37 g). The reaction system was subjected to three evacuation-hydrogen filling cycles for degassing, followed by stirring the reaction for 15 h at room temperature under hydrogen atmosphere (balloon). The reaction process was monitored by thin layer chromatography (TLC). Upon completion of the reaction, the reaction mixture was filtered through a diatomaceous earth pad to remove the catalyst. The filtrate was concentrated under reduced pressure and the resulting residue was dried under high vacuum to afford methyl 2-(5-amino-2-methylphenyl)acetate (3.61 g, 98% yield) as a white solid. The purity of the product was confirmed by nuclear magnetic resonance hydrogen spectroscopy (1H NMR) and no further purification was required.

[1] Patent: WO2018/138354, 2018, A1. Location in patent: Page/Page column 38
[2] Patent: WO2018/138359, 2018, A1. Location in patent: Page/Page column 41; 42
[3] Journal of the Chemical Society, Perkin Transactions 1, 2000, # 10, p. 1601 - 1608
[4] Patent: WO2008/51757, 2008, A1. Location in patent: Page/Page column 33; 34
[5] Patent: WO2005/34869, 2005, A2. Location in patent: Page/Page column 42