To a solution of 2-adamantan-1-ylmethyl-5-phenyl-1H-pyrrole-3-carboxylic acid ethyl ester (Example 1, step b) (726 mg, 2.00 mmol) in DMF (3 ml) was added sodium hydride (60% dispersion in oil) (100 mg, 2.50 mmol) in small portions at 0° C. The mixture was stirred at room temperature for 30 min, then iodomethane (1.00 ml, 16.0 mmol) was added and the stirring was continued for 1 h. The reaction mixture was partitioned between ethyl acetate and 1M hydrochloric acid, the organic layer was washed with water, dried, and the solvent was evaporated to afford the product as a white solid (620 mg, 82%). 1H NMR (300 MHz, CDCl3) 7.35 (5H, m), 6.64 (1H, s), 4.27 (2H, q), 3.51 (3H, s), 2.80 (2H, br s), 1.96 (3H, br s), 1.64 (12H, m), 1.35 (3H, t).
