反应详情

温度

0 °C

A solution of methyl 7-amino-2,3-dihydro-1,4-benzodioxine-5-carboxylate (4.89 g, 23.3 mmol) in ethylene glycol dimethyl ether (15 mL) was cooled to −5° C. and then slowly added boron trifluoride diethyl etherate (3.85 mL, 30.3 mmol) followed by tert-butyl nitrite (3.05 mL, 25.6 mmol). The resulting gray suspension was allowed to warm to 0° C. and stirred for 1 h, at which time it was filtered and rinsed with ethyl acetate to give 6.24 g (93%) of difluoroboranylium {8-[(methyloxy)carbonyl]-2,3-dihydro-1,4-benzodioxin-6-yl}diazenide as a gray powder: 1H NMR (400 MHz, d6-DMSO): 8.73 (br s, 1H), 8.32 (br s, 1H), 4.64 (br m, 2H), 4.47 (br m, 2H), 3.88 (s, 3H).

1. filtrationwas filtered
2. washrinsed with ethyl acetate