反应详情

To a solution of 1.0 g (2.94 mmol) 5-chloro-2-ethoxalylamino-3-nitrobenzotrifluoride in 75 ml tetrahydrofuran was added 25 ml dimethylformamide and 1.0 ml 25% aqueous ammonia. The mixture was hydrogenated at atm. pressure by using 100 mg 5% Pt-C as a catalyst. When the hydrogen uptake was completed, the catalyst was filtered off, and the filtrate was evaporated in vacuo. The residue was stirred with 1N aqueous hydrochloric acid to give 0.66 g (80%) of 7-chloro-1-hydroxy-5-trifluoromethylquinoxaline -2,3(1H,4H)-dione. M.P. 275° C. decomp. 1H-NMR (DMSO-d6): 11.7 (2H, m), 7.60 (1H, d), 7.43 (1H, d).

1. filtrationthe catalyst was filtered off
2. customthe filtrate was evaporated in vacuo