| 摘要 |
The nitro compound obtainable by mononitrating the diazo oxide from 1-amino-2 : 3-oxynaphthoic acid in concentrated sulphuric acid is treated with a reagent capable of eliminating the diazo group. 6-Nitro-2 : 3-oxynaphthoic acid may be so obtained, but if the elimination of the diazo group is effected with the aid of a strong reducing agent, in a proportion sufficient to provide at least about eight atoms of hydrogen per molecule of nitrodiazo compound, 6-amino-2 : 3-oxynaphthoic acid results; the latter compound is also obtainable by reducing 6-nitro-2 : 3-oxynaphthoic acid. Examples are given of the production of the 6-nitro compound with the aid of the following reagents for eliminating the diazo group: (1) cuprous oxide; (2) titanous chloride; (3) sodium stannite; (4) formic acid and copper; other specified reagents are finely divided copper or zinc dust in an aqueous alkaline medium, ferrous chloride in suspension in alcohol or glacial acetic acid, aluminium bronze in sulphuric acid, and also hydroxylamine, hydrazine or an alcoholic suspension of phenylhydrazine. Examples are given also of the production of the 6-amino compound from the nitrodiazo compound with the aid of the following reducing and diazoeliminating agents: (1) aqueous sodium sulphide; (2) stannous chloride and hydrochloric acid; (3) alkaline sodium hydrosulphite; other reagents which are also suitable, when used in sufficient proportion, are sodium stannite, titanous chloride, and zinc dust in an alkaline medium. An example is given also of the reduction of the 6-nitro compound to the 6-amino compound with zinc and caustic soda. The N-acetyl and N-benzoyl derivatives of the 6-amino compound are described. Specification 326,971, [Class 2 (iii)], is referred to.
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