US 6,242,602 B1 · One pot synthesis of 5,10-dihydrophenazine compounds and 5,10-substituted dihydrophenazines

Abstract

Dihydrophenazines and bis(dihydrophenazines) are prepared in high yield under commercially viable reaction conditions by reacting a catechol with a 1,2-diaminoaryl compound, wherein either the catechol or the 1,2-diaminoaryl compound is provided in at least 50% molar stoichiometric excess. The product may be oxidized to the corresponding phenazine, but is preferably derivatized at one or both of the 5,10-positions to form a monosubstituted or disubstituted dihydrophenazine or bis(dihydrophenazine). Most preferably, 5,10-dialkyl-5,10-dihydrophenazines are prepared starting from catechol and 1,2-diaminoaryl compound in a one pot synthesis. The products are useful as dyes, and in particular as chromophores in electrochromic systems.

Claims49

Dependent claims

A process for the preparation of a phenazine group-containing compound, comprising the steps of:

providing a 1,2-diaminoaryl compound and a catechol, wherein either the 1,2-diaminoaryl compound or the catechol is provided in at least 50% molar stoichiometric excess;
reacting the 1,2-diaminoaryl compound with the catechol;
and
obtaining a 5,10-dihydrophenazine group-containing compound.

1 more element

A one pot process for the synthesis of a 5-substituted, 10-substituted, or 5,10-dihydrophenazine or bis(5,10-dihydrophenazine) substituted at one or more of the phenazine nitrogen atoms, said process comprising:

a) introducing into a reaction vessel a 1,2-diaminoaryl compound corresponding to the formula (2) or (3):
where each R independently is a substituent which is non-reactive under the synthesis conditions and n is an integer from 0 to 4;
where each R independently is as defined above and each m independently is an integer of 0 to 3;
and wherein X is a covalent bond or an organic linking group unreactive under the synthesis conditions, or X is an aromatic ring system fused to at least one ring at adjacent positions and m is 0 to 3 on each respective ring to which said aromatic ring system is fused;
b) introducing into said reaction vessel a catechol corresponding to the formula (1)
where R is as previously defined, n is an integer of 0-4, or where two or more Rn are linked together into an aromatic or cycloaliphatic ring structure, wherein said catechol is present in greater than a one fold molar excess based on the 1,2-diaminoaryl compound, or an organic solvent is present, or said catechol is present in stoichiometric excess and an organic solvent is present;
c) heating the reaction vessel containing a) and b) until the reaction reaches a desired degree of completion to obtain an impure mixture of dihydrophenazine(s);
d) purifying said impure mixture of dihydrophenazine(s) by washing with a liquid in which said catechol and said 1,2-diaminoaryl compound are soluble but said dihydrophenazine is only sparingly soluble to obtain a purified dihydrophenazine;
e) alkylating said purified dihydrophenazine(s) in a reaction mixture containing an amount of a reducing agent effective to prevent oxidation of said dihydrophenazine(s) to the corresponding phenazine(s);
and
f) recovering an alkylated dihydrophenazine or bis(dihydrophenazine) alkylated at least at one of the phenazine nitrogen ring positions.

8 more elements

Dependencies are inferred from the claim text.

One pot synthesis of 5,10-dihydrophenazine compounds and 5,10-substituted dihydrophenazines

Life of this patent

One pot synthesis of 5,10-dihydrophenazine compounds and 5,10-substituted dihydrophenazines

Life of this patent

Abstract

Claims49