Lithium Hydroxide → 3-Amino-5-sulphamyl-4-(beta,beta,beta-trifluoroethoxy)-benzoic acid

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Reaction Steps

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.

Provenance & Evidence