Diisopropylethylamine → Tert-butyl 4-(3-(3,5-dimethoxybenzylamino)-4-(2,2,2-trifluoroacetyl)-phenyl)piperazine-1-carboxylate

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Reaction Steps

A solution of 1-(2-(3,5-dimethoxybenzylamino)-4-fluorophenyl)-2,2,2-trifluoroethanone (527 mg, 1.47 mmol), N-Boc-piperazine (296 mg, 1.62 mmol) and N,N-diisopropylethylamine (0.51 mL, 2.94 mmol) in acetonitrile was stirred at reflux for 48 h. The reaction mixture was cooled down and concentrated under reduced pressure. The residue was taken up in dichloromethane, washed with water, dried and concentrated in vacuo to yield 1.04 g of the crude aniline. The crude product was purified by PTLC (20% ethyl acetate in hexanes) to yield 230 mg (30%) of tert-butyl 4-(3-(3,5-dimethoxybenzylamino)-4-(2,2,2-trifluoroacetyl)phenyl)piperazine-1-carboxylate: 1H NMR (400 MHz, CD3OD): δ 9.32 (br t, 1H), 7.63 (dd, 1H), 6.50 (d, 2H), 6.37 (t, 1H), 6.19 (dd, 1H), 5.81 (d, 1H), 4.39 (d, 2H), 3.77 (s, 6H), 3.52-3.49 (m, 4H), 3.35-3.32 (m, 4H), 1.48 (s, 9H). MS (ESI) m/z: Calculated: 523.23; Observed: 546.3 (M++23).

Provenance & Evidence