Patent 6359131 Issued on March 19, 2002. Estimated Expiration Date: 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.
The 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.
Chem. Abstract 95-23-8 and 73778-92-4
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