N-mono- and di-oxobutyl-para-aminosalicylic acids

摘要

The invention comprises N-mono-g -oxobutyl- and N-di-g -oxobutyl-p-aminosalicylic acids and their alkaline earth and alkali metal salts, and a process for the preparation of the above compounds by reacting p-aminosalicylic acid or its alkaline earth or alkali metal salts with vinyl methyl ketone or a beta-halogenoethyl methyl ketone, e.g. the chloro- or bromo-compound, or by treating N-mono- or di-3-butinyl-p-aminosalicylic acid with water in the presence of acid mercuric salts, or by the action of vinyl acetylene on p-aminosalicylic acid in the presence of water and in the presence of acid mercuric salts. When a beta-halogeno-ethyl methyl ketone is employed in the reactions referred to above, a hydrogen halide acceptor may be used, e.g. pyridine, or sodium carbonate or bicarbonate. An organic solvent miscible with water may be added to the reaction using vinyl acetylene. The alkali metal and alkaline earth metal salts may be formed from the free acids by normal methods, and the salts may be converted into the free acids. In the examples, N-g -oxobutyl-p-aminosalicylic is prepared and its sodium salt.