Nitric Acid → 3-Benzofurancarboxylic acid, 5-bromo-2-(4-fluorophenyl)-6-nitro-, ethyl ester
Reaction equation
[Br:1][C:2]1[CH:3]=[CH:4][C:5]2[O:9][C:8]([C:10]3[CH:15]=[CH:14][C:13]([F:16])=[CH:12][CH:11]=3)=[C:7]([C:17]([O:19][CH2:20][CH3:21])=[O:18])[C:6]=2[CH:22]=1.[N+:23]([O-])([OH:25])=[O:24]>C(Cl)(Cl)Cl>[Br:1][C:2]1[C:3]([N+:23]([O-:25])=[O:24])=[CH:4][C:5]2[O:9][C:8]([C:10]3[CH:11]=[CH:12][C:13]([F:16])=[CH:14][CH:15]=3)=[C:7]([C:17]([O:19][CH2:20][CH3:21])=[O:18])[C:6]=2[CH:22]=1Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
To a solution of ethyl 5-bromo-2-(4-fluorophenyl)benzofuran-3-carboxylate (50 g, 137.6 mmol) in CHCl3 (500 mL), fuming HNO3 (50 mL) was added dropwise at −15° C. and the mixture was stirred for 0.5 hour. The reaction mixture was poured into ice water and extracted with CH2Cl2. The organic layer was washed with a.q. sat. NaHCO3 and brine, after removed the most of solvent, the resulting residue was crystallized with petroleum ether/dichloromethane=20/1 to provide product of ethyl 5-bromo-2-(4-fluorophenyl)-6-nitrobenzofuran-3-carboxylate (35 g, yield: 66%). 1H-NMR (CDCl3, 400 MHz) δ 8.36 (s, 1H), 8.02˜8.04 (m, 3H), 7.13˜7.18 (m, 2H), 4.36˜4.41 (m, 2H), 1.37 (t, J=4.0 Hz, 3H). MS (M+H)+: 408/410.