摘要 |
There is described a process for producing vat dyes by carbazolation of anthrimides effected by reaction of a complex of titanium tetrahalide (chloride or bromide) with a sulfone in a medium of the sulfone as the solvent. Further subject matter of the invention is a single-vessel process, in which both the production of the anthrimide and the cyclisation thereof can be performed, without isolation of an intermediate, in a sulfone as the reaction medium. |