反应详情

1,4-Dihydro-2,6-dimethyl-4-(3-isothiocyanatophenyl)-3,5-pyrazinedicarboxylic acid, dimethyl ester (25 mg, 0.069 mmol) was refluxed with 4-tert-butyl-piperidine-1-propanamine (16 mg, 0.081 mmol) in 2 mL of benzene for 30 min. Chromatographic purification (silica gel, eluted with 10% (v/v) methanol in methylene chloride) of the resultant residue after concentration in vacuo gave the title compound as a yellow powder (64%); 1H-NMR (CDCl3) δ 8.20 (br, 1H), 7.98 (br, 1H), 7.05 (t, 1H, J=8.1 Hz), 6.79 (br, 1H), 6.66 (d, 1H, J=8.0 Hz), 6.50-6.60 (m, 2H), 3.70 (s, 6H), 3.55 (m, 2H), 3.28 (m, 2H), 2.72 (m, 2H), 2.30-2.55 (m, 2H), 2.37 (s, 6H), 1.86 (m, 2H), 1.50-1.80 (m, 2H), 0.95-1.25 (m, 1H), and 0.79 (s, 6H); 13C-NMR (CDCl3) δ 180.9, 166.3, 152.8, 150.1, 129.9, 116.3, 112.7, 109.9, 108.5, 53.9, 51.8, 44.9, 42.1, 32.1, 29.8, 27.2, 24.7, 24.5, and 17.8.

1. customChromatographic purification (silica gel, eluted with 10% (v/v) methanol in methylene chloride) of the resultant residue
2. concentrationafter concentration in vacuo