Patent ID: 6617473
Filing Date: 2003-09-09
Classification: C07C

Abstract:
A process for preparing substituted dibenzosuberenones of the formula in whichR1 to R10 are identical or different and represent hydrogen, fluorine, chlorine, bromine, cyano, iodine, a straight-chain or branched aliphatic hydrocarbon radical having 1 to 8 carbon atoms, a straight-chain or branched acyl radical having 1 to 8 carbon atoms, a substituted aryl radical, a substituted hetaryl radical, or one of the groups â€”Xâ€”R12â€”Xâ€”C(&boxH;O)â€”Yâ€”R11 or â€”C(&boxH;O)â€”Yâ€”R11 in whichR11 represents a straight-chain or branched alkyl radical having 1 to 8 carbon atoms, R12 represents a straight-chain or branched alkyl radical or acyl radical having 1 to 8 carbon atoms and X and Y are identical or different and represent â€ƒâ€”Oâ€”, â€”N(H)â€”, â€”Sâ€”, â€”N(R13)â€”, whereR13 represents a straight-chain or branched alkyl radical having 1 to 8 carbon atoms, comprising the step of catalytically dehydrogenating dibenzosuberones of the formula, in which,R1 to R10 are each as defined above, in the presence of from 0.001 to 30% by weight, based on the starting material, of a catalyst comprising an element of the 8th transition group, which is optionally supported, and from 0.2 to 10 parts by weight, based on one part by weight of starting material, of &agr;,&bgr;-unsaturated (carbonyl compounds as hydrogen acceptors.