[CH3:1][O:2][C:3](=[O:22])[C:4]1[CH:9]=[C:8]([N+:10]([O-])=O)[C:7]([NH2:13])=[C:6]([F:14])[C:5]=1[NH:15][C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1.[CH:23](O)=O>C(O)C.[OH-].[OH-].[Pd+2]>[CH3:1][O:2][C:3]([C:4]1[C:5]([NH:15][C:16]2[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=2)=[C:6]([F:14])[C:7]2[N:13]=[CH:23][NH:10][C:8]=2[CH:9]=1)=[O:22]4-Amino-3-fluoro-5-nitro-2-phenylamino-benzoic acid methyl ester 26a (16.70 g, 54.71 mmol), formic acid (250 mL, 6.63 mol) and 20% Pd(OH)2/C (9.00 g, 16.91 mmol) in ethanol (250 mL) are stirred at 40° C. for two hours under N2 and then at 95° C. for 16 hours. The reaction mixture is cooled to room temperature and filtered through Celite rinsing with ethyl acetate. The filtrate is concentrated under reduced pressure to give a yellow solid. The solid is triturated with diethyl ether to give 13.47 g (86%) of the desired product as a tan solid. MS APCI (+) m/z 286 (M+1) detected; MS APCI (−) m/z 284 (M−1) detected.
Wird geladen…
