反应详情

To hydrazide (34.07 g, 183 mmol) of step 2 in 275 mL of water was added KHCO3 (18.33 g, 183 mmol) followed by BrCN (19.39 g, 183 mmol) portionwise. After 3 h, the solid was filtered, washed with cold water and dried to afford the title compound. Additional compound could be recovered from the aqueous phase by extraction (ether-hexane, 1:1). 1H NMR (400 MHz, acetone-d6): δ 6.54 (s, 2H), 6.01 (s, 1H), 2.22 (m, 1H), 2.08 (m, 1H) and 0.99 (m, 3H).

1. filtrationthe solid was filtered
2. washwashed with cold water
3. customdried