General procedure for the synthesis of 2-methyl-3-nitrophenylacetic acid from 2-methyl-3-nitrobenzonitrile: To a solution of 2-methyl-3-nitrophenylacetonitrile (500 mg, 2.8 mmol) in ethanol (30 mL) was added a 20% w/v aqueous KOH solution (30 mL). The reaction mixture was heated to reflux for 18 hours. After completion of the reaction, it was cooled to room temperature and extracted with dichloromethane (50 mL) to separate the aqueous layer. The aqueous layer was acidified to pH 2 with 2N HCl aqueous solution and subsequently extracted with ethyl acetate (50 mL) and dichloromethane (50 mL). The organic phases were combined, dried over anhydrous magnesium sulfate, and the solvent was concentrated under reduced pressure to afford the light brown solid product 2-methyl-3-nitrophenylacetic acid (470 mg, 86% yield). The product was characterized by 1H NMR (400 MHz, CD3OD) with chemical shifts δ (ppm) of 7.66 (d, 1H), 7.50 (d, 1H), 7.34 (t, 1H), 3.79 (s, 2H), 2.37 (s, 3H).
