To a solution of tert-butyl 6-aminoindoline-1-carboxylate (3.2 g, 13.68 mmol) in CH2Cl2 (135 mL) was added iPr2NEt (14 mL), 3-[(quinolin-4-ylmethyl)amino]thiophene-2-carboxylic acid hydrochloride (5.27 g, 16.42 mmol), EDC (3.93 g, 20.5 mmol), DMAP (0.81 g, 6.63 mmol), and HOAt (5.5 mL. 0.5M in DMF). The resulting mixture was then heated to reflux under N2 atmosphere. After 8 h the reaction was cooled to rt and then washed with 50% NaCl solution. The organic layer was dried over Na2SO4, filtered, and concentrated in vacuo to yield a residue that was purified by silica gel chromatography (80% EtOAc in Hexanes 100% EtOAc) to yield tert-butyl 6-({[3-[(quinolin-4-ylmethyl)amino]thien-2-yl]carbonyl}amino)indoline-1-carboxylate as a yellow solid. MS (ES+): m/z 501 [M+1]. 1H NMR (d6-DMSO, 400 MHz): δ1.48 (s, 9H), 2.99 (t, J=8.4 Hz, 2H), 3.90 (t, J=8.4 Hz, 2H), 5.06 (d, J=6.0 Hz, 2H), 6.78 (brs, 1H), 7.07 (d, J=8.4 Hz, 1H), 7.40 (d, J=4.4 Hz, 1H), 7.56 (d, J=5.6 Hz, 1H), 7.66 (t, J=6.8 Hz, 1H), 7.78 (t, J=6.8 Hz, 1H), 8.04 (m, 2H), 8.21 (d, J=8.0 Hz, 1H), 8.82 (d, J=4.4 Hz, 1H), 9.35 (s, 1H).
