Aminopyrazine → (2-Methoxy-5-nitrophenyl)-3-pyrazin-2-yl-urea

Participants

Reaction Steps

A mixture of 2-methoxy-5-nitrophenyl isocyanate (5.0 g, 25 mmol) and aminopyrazine (2.5 g, 26 mmol) in tetrahydrofuran (THF, 250 mL) was stirred at reflux for 24 hours. The product was precipitated from the cooled reaction mixture and was collected by filtration, washed with ethyl acetate, and dried in vacuo (4.3 g, 57%). 1H NMR (300 MHz, d6-DMSO) (mixture of rotamers) δ: 10.38 (br, s, 1H), 10.27 (s, 1H), 9.39, 8.88 (2 singlets, 1H), 9.10 (d, 1H), 8.33 (s, 1H), 8.26 (d, 1H), 7.98-8.25 (m, 1H), 7.97-7.84 (m, 1H), 4.05, 4.03 (2 singlets, 77:28 ratio, 3H).

Provenance & Evidence