Process for preparing dioxazine compounds
March 24, 2020. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesBis-(benzimidazolone-azo-acetoacetylamino)-phenylene pigments Iminoisoindoline pigments and processes for the preparation thereof Process for the manufacture of 5-acetoacetylamino-benzimidazolone Process for the manufacture of a violet organic pigment, C.I. Pigment Violet 23 Process for the preparation of aryldiazosulfonates Dioxazine pigments Ink comprising a water-soluble triphendioxazine dye Dry toners containing fanal pigments based on cationic dyes Water-soluble azo compounds, containing a diazo component with a heterocyclic moiety, and a coupling component with a fibre-reactive group, suitable as dyestuffs Triphendioxazine compounds InventorsAssigneeApplicationNo. 535502 filed on 03/24/2000US Classes:544/99Polycyclo ring system having the oxazine ring as one of the cyclosExaminersPrimary: Raymond, Richard L.Assistant: Patel, Nimeshkumar D. Attorney, Agent or FirmForeign Patent References
International ClassC07D 265/34Foreign Application Priority Data1999-03-25 DEAbstractThe process provides a process for preparing dioxazines by ring closure of a compound of the formula (II) ##STR1##in which R1 is hydrogen or C1 -C8 alkyl in the presence of a ring closure agent, which comprises using as reaction medium an aryl alkyl ether of the formula (III) or a mixture of aryl alkyl ethers of the formula (III) ##STR2##in which n is an integer from 0 to 2 and R2 is ethyl if n is 0 or is methyl if n is 1 or 2.Other References
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