Patent GB-419062-A (GB)
Title: Improvements in the manufacture and production of condensation products
IPC: C09B3/06
Filed: 1933-03-31
Abstract: Colouring matters having strong fluorescence (usually green) and specially suitable for colouring fuel mixtures such as benzine and benzene, or for colouring lubricating oils, are prepared by subjecting benzanthrene or compounds capable of reacting like benzanthrene to a condensing treatment, e.g. by heating the initial material, preferably in the presence of a metal oxide difficultly reducible to metal, at a temperature between the boiling point of the material and 800 DEG  C.ALSO:Condensation products of the benzanthrene series are prepared by subjecting to a condensing treatment compounds capable of reacting like benzanthrene by heating the initial material, preferably in the presence of a metal oxide difficulty reducible to metal, at a temperature between the boiling point of the initial material and about 800 DEG  C., or by heating benzylnaphthalene, benzanthrene or dihydro-benzanthrene in the liquid phase with sulphur or lead dioxide or another substance exerting a dehydrogenating action, or by heating benz-anthrene or dihydrobenzanthrene containing one hydroxy group or one halogen atom in the 10-position with a substance capable of reacting like benzanthrene, if desired in the presence of a substance favouring the splitting off of water, or by heating benzanthrenes substituted in the 10-position by two halogen atoms or two hydroxy groups with benzanthrene, if desired also in the presence of a substance favouring the splitting off of water.  Compounds capable of reacting like benzanthrene are dihydrobenzanthrene (which is formed in the production of benzanthrene from a -benzylnaphthalene), a -benzylnaphthalene, benzanthrenes or dihydro-benzanthrenes substituted in the 10-position by hydroxy or halogen.  Reaction is effected under such conditions as to effect a condensation of two molecules of the initial material; when heating alone temperatures of 300--800 DEG  C. are generally suitable; when employing dehydrogenating agents such as sulphur, selenium, lead oxide, sodamide, aluminium-chloride, difficulty reducible metal oxides, bleaching earths, as for example tonsil or silica gel, temperatures below 300 DEG  C. can be used and similarly when an agent binding water such as phosphoric acid is employed.  The products have a high colouring power and strong fluorescence (usually green), they are especially suitable for colouring bulk products such as fuel mixtures such as benzine and benzene or for colouring lubricating oils.  In examples: (1) a -benzylnaphthalene vapour is led over a catalyst consisting of magnesium oxide provided with a surface layer of graphite at 750--780 DEG  C. to give a green fluorescent material which is probably a condensation product of two molecules of benzanthrene; a similar result is obtained using benzanthrene or dihydrobenzanthrene; (2) a mixture of benzanthrene and dihydrobenzanthrene (prepared by leading a -benzylnaphthalene in vapour form over oxides not reducible to metal under the reaction conditions according to Specification 409,770) is mixed with sulphur (or lead dioxide) and heated to 280 DEG  C.; (3) a mixture of benzanthrene and dihydrobenzanthrene is treated with chlorine in carbon tetrachloride when 10-monochlorbenzanthrene separates out; the mixture is then boiled under reflux; (4) a mixture of benzanthrene and benzanthrone is heated for 3 hours at 320 DEG  C.; using condensing agents such as tonsil or phosphoric acid reaction may be effected at 250 DEG  C.; (5) 10-hydroxydihydrobenzanthrene is heated with tonsil at 200--250 DEG  C.; (6) 10-dichlorbenzanthrene (prepared by acting on benzanthrene with phosphorus pentachloride) is heated in chlorbenzene at 100-120 DEG  C.  Specifications 356,189 and 369,613 also are referred to.