Piperidine (30 μL, 2.0 mmol), Pd2dba3 (2.7 mg, 0.003 mmol), potassium t-butoxide (59 mg, 0.53 mmol) and 1,3-bis-(2,6-diisopropylphenyl)-4,5-dihydroimidazol-2-ylidene HCl salt (2.6 mg, 0.006 mmol) are added sequentially to a solution of 3-{[2-(4-chloro-3-trifluoromethyl-phenyl)-benzo[b]thiophen-5-ylmethyl]-amino}-propionic acid tert-butyl ester (72 mg, 0.15 mmol) in 1,4-dioxane (0.8 mL). The mixture is irradiated in a microwave at 100° C. for 1 hour. The reaction is quenched with water and the mixture is concentrated in vacuo. The residue is dissolved in THF and aqueous 2N NaOH (4 mL, 1:1 v/v), and stirred at 60° C. for 3 hours. It is concentrated and purified with preparative LCMS to afford 20 mg of 3-{[2-(4-piperidin-1-yl-3-trifluoromethyl-phenyl)-benzo[b]thiophen-5-ylmethyl]-amino}-propionic acid, which is converted to HCl salt: 1H NMR (400 MHz, CD3OD) δ 8.15-8.00 (m, 4 H), 7.87 (s, 1 H), 7.63 (d, 1 H), 7.57 (d, 1 H), 4.48 (s, 2 H), 3.44 (t, 2 H), 3.03 (t, 4 H), 2.89 (t, 2 H), 1.90-1.80 (m, 4 H), 1.75-1.65 (m, 2 H); MS (ES) 463.4 (M+H+).
