Ammonia → Anthranilamide

Participants

Reaction Steps

It is reported in J. prakt. Chem., 30 (1884), [2], 467 et seq. and in J. org. Chem. 13 (1948), 347 et seq. and 24 (1959), 1214 et seq. that isatoic anhydride reacts with aqueous ammonia to give anthranilic acid amide and o-ureidobenzoic acid. The reaction of 5,7-dichloroisatoic anhydride with ammonia leads to 6,8-dichlorobenzoylurea (J. org. Chem . 3 (1938), 414 et seq. and 12 (1947), 743), whilst other chlorine-substituted isatoic anhydrides give only moderate yields of chlorinated anthranilic acid amides (J. org. Chem. 26 (1961) 613 et seq.). A corresponding reaction of 6-nitroisatoic anhydride, as described in J. prakt. Chem., 30 (1884), [2], 467 et seq., gives 5-nitroanthranilic acid amide in poor yield and purity. It was only possible to establish a decomposition point for the resulting end product, and this lay about 30° C. below the melting point of the pure end product. The product is apparently contaminated by nitroureidobenzoic acid and can be separated off and purified only by a complicated procedure, for example by salt formation with hydrochloric acid or sulfuric acid and subsequent precipitation with alkali metal hydroxide solution; this process is therefore unsuitable, particularly for a large-scale industrial preparation.

Provenance & Evidence