反应详情

3-Nitro-5-sulphamyl-4-(β,β,β-trifluoroethoxy)-benzoic acid (2g) in water (30 ml) was adjusted to a pH of 9 by addition of lithium hydroxide, and the resulting solution was hydrogenated at room temperature and at a hydrogen pressure of 1.1 atmospheres after addition of Pd-on-carbon catalyst (0.2 g catalyst containing 10% Pd). After the hydrogen uptake had become negligible, the catalyst was removed by filtration, and the 3-amino-5-sulphamyl-4-(β,β,β-trifluoroethoxy)-benzoic acid was precipitated from the filtrate by addition of 4N hydrochloric acid until a pH of 2.5. After recrystallization from aqueous ethanol and drying, the melting point of the compound was 253°-254° C.

1. customthe catalyst was removed by filtration
2. customthe 3-amino-5-sulphamyl-4-(β,β,β-trifluoroethoxy)-benzoic acid was precipitated from the filtrate by addition of 4N hydrochloric acid until a pH of 2.5
3. customAfter recrystallization from aqueous ethanol
4. customdrying
5. customwas 253°-254° C.