N,N-Diisopropylethylamine (50 μL, 0.3 mmol) was added to a mixture of 1-[4-(2-amino-1,3-thiazol-4-yl)phenyl]cyclopropanecarboxylic acid (26.0 mg, 0.1 mmol), (1S)-(+)-10-camphorsulfonic acid-3H-spiro-[2-benzofuran-1,3′-pyrrolidin]-3-one (1:1) (42.1 mg, 0.01 mmol) and BOP (57.0 mg, 0.13 mmol) in DMF (0.5 mL) at room temperature, and the reaction mixture was stirred for about 5 hours (the completion of the reaction was determined by HPLC). The crude product was purified by prep-HPLC. LC-MS: 432.1 (M+H)+.
