反应详情

温度

-20 °C

A mixture of 0.960 g (3.48 mmol) of 7, 1.60 g (35 mmol) of hydrazine hydrate (62% hydrazine), and 5 mL of EtOH was refluxed for 15 h. The mixture was cooled to −20° C., vacuum filtered, washed with 50 mL of ice-cold 1:1 EtOH:H2O, and dried to give 0.832 g (87% yield) of (2-bromo-4,5-dimethoxy benzoyloxy)hydrazine (8) as a white, needle-like crystalline solid. The above procedure was repeated on 2.79 g of the starting ester 7 to result in 2.77 g (99% yield) of 8. 1H NMR (200 MHz, CDCl3) δ 6.97 (s, 1H), 6.86 (s, 1H), 3.85 (s, 6H). HRMS Calculated for C9H12O3N2Br 275.0031. found 275.0037.

1. temperaturewas refluxed for 15 h
2. filtrationvacuum filtered
3. washwashed with 50 mL of ice-cold 1:1 EtOH
4. dry with materialH2O, and dried