反应详情

To a solution of 50.1 mg (0.311 mmol) of 11a and 52.0 mg (0.753 mmol) of NaNO2 in 1.5 mL of aqueous 0.2N NaOH in an ice-bath was added dropwise 1 mL of aqueous 2N H2SO4. A red precipitate was observed. The mixture was stirred in the ice-bath for 2 h and at 25° C. for 4 h, filtered and washed with water, and dried to leave 37 mg (62%) of 14a as a red solid, mp 241°-242° C. 1H NMR (CDCl3 +DMSO-d6), 6.83 (m, 2), 7.069 (t, 1, J=7.2), 8.544 (d, 1, J=8.1), 11.228 (m, 1). MS, 190 (100, M+), 162 (50), 145 (65), 117 (30). High resolution MS, Calcd for C9H6N2O3 190.0375, found 190.0377.

1. filtrationfiltered
2. washwashed with water
3. customdried