To a solution of 5-bromo-2-methyl-benzoic acid (1.35 g, 6.15 mmol) in THF (15 ml), CH2Cl2 (15 ml) and DMF (14.27 μl, 184.57 μmoles) is added dropwise oxalyl chloride (587.12 μl, 6.77 mmoles) at 0° C. and reaction mixture is slowly allowed to warm to ambient temperature. After 2 hours, the solvent is removed under reduced pressure. To the residue CH2Cl2 (30 ml) is added and reaction mixture is cooled to 0° C., then ethyl 4-amino-3,5-dimethyl-benzoate (1.19 g, 6.15 mmol) is added followed by 4-pyridinamine, N,N-dimethyl-(37.58 mg, 307.61 μmoles) and pyridine (1.49 ml, 18.46 mmoles). The cooling bath is removed and the clear solution is allowed to warm to ambient temperature. After 5 hours, the solvent is removed and the reaction mixture is diluted with ethyl acetate and washed with 1N HCl, saturated solution of sodium bicarbonate, and brine. The organic layers are combined and dried over anhydrous Na2SO4, filtered, and concentrated under reduced pressure. The resulting residue is triturated with hexanes and the resulting solids were collected by filtration to give the title compound as a white solid (1.80 g; 75.2%). Mass spectrum (m/z): 390.2 (M+1).
