The Manufacture of Substituted Amido-benzoic Acids, and of Anthranilic Acid and Colouring Matters therefrom.

摘要

19,202. Ellis, G. B., [Pertsch, F. A.]. Oct. 26. 5-Amido 2-acetylamidobenzoic acid is produced by heating 5-nitro 2-amidobenzoic acid with glacial acetic acid and ace ic anhydride at 125‹ C. for six hours. and reducing the 5-nitro-2 acetylamidobenzoic acid thus formed bv means of zinc and acetic acid or by other reducing-agents. Anthranilic acid is produced by diazotizing 5-amido-2-acetylamidobenzoic acid in solution in absolute alcohol by means of a current of nitrous acid at 10‹ C., expelling the excess of nitrous acid by a current of dry air, boiling the diazo solution for one hour, expelling the alcohol, and then hydrolyzing the acetylamido group by heating with hydrochloric acid. The anthranilic acid is extracted from the solution either by adding sodium acetate and extracting with ether, or by precipitating it from the acid solution by means of an excess of ammonium acetate. Dyes, artificial, are produced from 5-amido-2-. acetylamidobenzoic acid by coupling its diazo compound with a molecular proportion of a phenol or an amine, such as a naphthol or naphthylamine sulphonic acid. The dyes thus obtained are converted into others by splitting off the acetyl group, diazotizing again, and combining the diazo compound with another molecular proportion of a phenol or amine.