GB253911A - Manufacture of cyclic hydrocarbons and derivatives thereof - Google Patents

Abstract

253,911. I. G. Farbenindustrie Akt.- Ges., (Assignees of Farbwerke vorm. Meister. Lucius, & Br³ning). June 22, 1925, [Convention date]. Addition to 251,270. Cyclic hydrocarbons, carbinols.-The process of the parent Specification is modified in the following ways (a) the vapours of aromatic alcohols or mixed aliphatic-aromatic alcohols, containing a methyl or methylene group in the o-position to the carbinol group, are subjected to ring closure by passage over a heated highly porous body; instead of the alcohols their derivatives such as ethers or esters may be employed; oxygen, air, or an agent which yields oxygen such as a nitro derivative, may be mixed with the alcohol vapour and an oxidation catalyst may be added to the contact mas ; (b) di- or tri-arylmethanes containing a methyl or methylene group in the o-position to the methane carbon are subjected to ring closure by passing their vapours over a heated contact mass in presence of an oxidizing agent and in the presence or not of an oxygencarrier. According to examples the following hydrocarbons are prepared:- (1) #-methylanthracene from m-xylylpbenylcarbinol or its acetate and air in the presence of active charcoal made as described in Specification 201,163, [Class 55 (ii) Gas manufacture &c.] ; (2) 1 : 4 : 6- trimethylanthracene from di-p-xylylcarbinol and air in presence of active charcoal containing copper and cobalt oxides; (3) #-methylanthracene from m-xylylphenylmethane vapour and air in presence of active carbon containing oxides of manganese and cobalt. The Specification as open to inspection under Sect. 91 (3) (a.) is not limited to the treatment of the di- and tri-arylmethanes in presence of air or an oxidizing agent; it also describes the preparation of the following compounds (1) 1 : 3- dimethyl-7 : 8-benzanthracene from the carbinol obtained by reducing a-naphthoylmesitylene; (2) an acenaphthanthracene from the carbinol made by reducing 5-(0-toluoyl)- acenaphthene; in this case the reaction is carried out under diminished pressure; (3) 1:2:7: 8-dibenzanthracene from the carbinol made by reducing a-naphthoyl-2- methylnaphthalene using silica gel as the contact material. This subject-matter does not appear in the Specification as accepted.