GB339659A - Improvements in the manufacture and production of dyestuffs and intermediate products - Google Patents

Abstract

339,659. Johnson, J. Y., (I. G. Farbenindustrie Akt.-Ges.). July 8, 1929. Ms - Naphthodianthrones, allo - ms - naphthodianthrones and ms-anthradianthrones are treated with nitrating agents, and the nitro groups in the nitro compounds thus obtained are partially or wholly reduced or directly replaced by halogen, if desired. As nitrating agent may be used concentrated nitric acid alone, or admixed with water. sulphuric acid, phosphoric acid, oleum or chlorsulphonic acid, and nitration is preferably effected in the presence of diluents such as mono-, di- and trichlorbenzene, bromobenzene, or quinoline. When nitrating with nitric acid in the presence of inorganic diluents such as sulphuric acid, simultaneous oxidation leading to the formation of hydroxy compounds, or dehydrogenation may occur; thus allo-ms-naphthodianthrone may be converted to nitro-ms-anthradianthrone. The replacement of the nitro group or groups in these compounds by halogen is effected by treating the compounds directly with halogens or agents which split off halogen, such as benzoyl chloride. In the case of the lower nitrated products further halogenation in addition to replacement of nitro groups by halogen, may occur. In examples, (1) allo-ms-naphthodianthrone is treated with nitric acid in nitrobenzene whereby mono- and dinitro-derivative are obtained; treatment with concentrated nitric acid alone gives a tetranitro derivative dyeing grey shades. Dichlor-allo-ms-naphthodianthrone (prepared according to Specication 303.184) treated with nitric acid in nitrobenzene yields a mononitrodichloro derivative; (2) ms-naplithodianthrone treated wth a mixture of nitric and sulphuric acids yields a mononitro derivative which yields with alkaline reducing agents the monoamino derivative; (3) ms-anthradianthrone is treated with nitric acid in nitrobenzene: (4) the mononitro-alloms-naphthodianthrone of (1) above is boiled with aqueous sodium sulphide to give the monamino derivative. Other reducing agents such as hydrazine hydrate or sodium hydrosulphite may be used, and by these means the other nitro derivatives specified above mav also be reduced. If this mononitro derivative is boiled with benzovl chloride an orange-red dyeing monochloro-allo-ms. naphthodianthrone is obtained.