Pentylamine → 4-(Pentylamino)naphthalene-1,2-dione

Participants

Reaction Steps

To a stirred suspension of 650 mg (3.45 mmol) of 4-methoxy-1,2-naphthoquinone in 20 mL of ethanol was added 0.80 mL (6.90 mmol) of pentylamine. The reaction mixture was stirred at room temperature for 60 min. The resulting red precipitate was collected by filtration and then triturated with 20 mL of ethyl acetate to afford 411.7 mg (49%) of 4-pentylamino-1,2-naphthoquinone, which was recrystallized from ethyl acetate: mp>215° C.; 1H NMR (300 MHz, CDCl3, TMS) δ 8.21 (dd, J=7.5, 1.6 Hz, 1H), 7.69 (td, J=7.7, 1.6 Hz, 1H), 7.61 (t, J=7.5 Hz, 1H), 7.49 (d, J=7.9 Hz, 1H), 5.86 (s, 1H), 5.76 (br s, 1H), 3.4-3.3 (m, 2H), 1.8-1.7 (m, 4H), 1.5-1.4 (m,4H), 0,95 (t, J=7 Hz, 3H); 13C NMR (75.5 MHz, d6 -DMSO, TMS) δ 182.0, 174.7, 154.8, 134.1, 131.2, 130.8, 127.8, 123.3, 98.0, 43.1, 28.7, 27.4, 21.8, 13.9. Analysis calculated for C15H17NO2 : C=74.04, H=7.06, N=5.7; Found: C=73.88, H=7.01, N=5.73.

Provenance & Evidence