Dimethylformamide → 1-(9H-fluoren-9-yl)methyl 4-tert-butyl 2-(2-(2-bromophenylamino)-2-oxoethyl)piperazine-1,4-dicarboxylate

Participants

Reaction Steps

To a solution of 2-bromoaniline (3.69 g, 21.44 mmol), and 2-(1-(((9H-fluoren-9-yl)methoxy)carbonyl)-4-(tert-butoxycarbonyl)piperazin-2-yl)acetic acid (10 g, 21.44 mmol) in a 1:1 solution of N,N-dimethylformamide:pyridine (100 mL) was added N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (10.27 g, 53.6 mmol). The reaction mixture was stirred at ambient temperature for 16 hours. The reaction mixture was partitioned between water and ethyl acetate. The organic layer was separated and was subsequently washed with brine (3×) and 1M HCl (3×). The organic solution was then concentrated onto silica gel and purified via flash chromatography (10-70% ethyl acetate/hexanes) to afford the title compound. 1H NMR (400 MHz, DMSO-d6) δ ppm 9.43 (s, 1H), 7.81-7.95 (m, J=7.67 Hz, 2H), 7.53-7.75 (m, 4H), 7.22-7.48 (m, 5H), 7.10 (dd, J=7.21 Hz, 1H), 4.56 (s, 1H), 4.17-4.42 (m, 3H), 3.61-3.98 (m, 3H), 2.89-3.18 (m, 2H), 2.62-2.88 (m, 2H), 2.49-2.58 (m, 1H), 1.32-1.50 (m, 9H); MS (APCI+) m/z 522.2 (M-Boc+H)+.

Provenance & Evidence