反应详情

温度

-78 °C

(The following reaction is done in an anhydrous N2 atmosphere.) Dissolve 2-Methyl-5-{2-nitro-4-[2-(3,4,5-trimethoxy-phenyl)-acetylamino]-phenyl}-furan-3-carboxylic acid (60) (33 mg, 0.07 mmol) in anhydrous DCM (1.0 mL), cool the solution to −78° C. and add dropwise BBr3 (66 μL, 0.70 mmol). Stir the reaction mixture for 10 min at −78° C. and after slowly warming up for additional 2 h at rt. Cool reaction mixture to 0° C., add dropwise water and DCM followed by MeOH to homogenize the mixture and remove solvent. Suspend the crude product in MeOH and filtrate it through a short pad of celite to obtain 2-Methyl-5-{2-nitro-4-[2-(3,4,5-trihydroxy-phenyl)-acetylamino]-phenyl}-furan-3-carboxylic acid (61) (22 mg, 72%) as a brown solid. 1H NMR (400 MHz, CD3OD): 2.62 (s, 3H); 3.53 (s, 2H); 6.40 (s, 2H); 6.88 (s, 1H); 7.73 (d, 1H, J=8.6 Hz); 7.80 (dd, 1H, J1=8.6 Hz, J2=2.0 Hz); 8.24 (d, 1H, J=2.0 Hz).

1. custom(The following reaction
2. temperatureafter slowly warming up for additional 2 h at rt
3. temperatureCool
4. customreaction mixture to 0° C.
5. stirringto homogenize the mixture
6. customremove solvent