4-Propylbenzoic acid → Methyl 4-propylbenzoate

To a 0° C. solution of 4-propylbenzoic acid (2 g, 12.18 mmol) in methanol (3.00 mL) and dichloromethane (10 mL) was added trimethylsilyldiazomethane (7.92 mL, 15.83 mmol), dropwise over a period of 5 min. Towards the end of the addition, the reaction mixture was pale yellow. The reaction was stirred at 0° C. for 30 min. and the excess diazo reagent was quenched by the slow addition of acetic acid at 0° C. (˜1.5 mL). The colorless solution was concentrated and partitioned between ether (20 mL) and sat. aq. sodium bicarbonate (10 mL). The ether layer was washed with brine (10 mL), dried over sodium sulfate and concentrated to yield methyl 4-propylbenzoate (2.1 g, 11.78 mmol, 97% yield) as a liquid. 1H NMR (400 MHz, CDCl3) δ ppm 7.95 (d, J=8.28 Hz, 2H) 7.24 (d, J=8.53 Hz, 2H) 3.90 (s, 3H) 2.61-2.67 (m, 2H) 1.59-1.71 (m, 1H) 0.94 (t, J=7.40 Hz, 1H).