1,6-Phenazine-diol

The discovery of a variety of new phenazine- and pyrazine-based natural products was reported in 2014. In addition to 1,6-phenazine-diol (92), a compound previously isolated from a number of different microorganisms, Jansen and collaborators extracted and identified its gjycosyl derivative, l-hydroxyphenazin-6-yI-a-D-arabinofuranoside (93), from Narmocystispusilla... 

TA2775>. The reaction of phenazine diol 177 with various chiral ditosylates 178 gave rise to phenazino-crown ethers 179 in enantiopure form. 

Intramolecular cyclization of 2-aminoindophenols at pH >8 affords phenazine-2,8-diols, e.g. phenazine-2,8-diol [(24 yield 100% (spectrophotometrically determined) mp >260 C]. °... 

Condensation of benzene-1,2-diamine (25) with 1,2-benzoquinones 26 under various reaction conditions affords phenazines 27 directly. 1,2-Benzoquinones should be prepared in situ to avoid selfcondensalion (see Houben-Weyl, Vol. 7/3 b, p 1). A solvent effect has been observed when conducting this reaction in different solvents in methanol the reaction product is phenazine-2,3-diol and in diethyl ether predominantly phenazine is formed. ... 

Benzo[6]phenazine has been similarly prepared from naphthalene-2,3-diol and benzene-1,2-di-amine. ... 

Benzene-1.3,5-triol (phloroglucinol) undergoes reaction with benzofuroxan in methanol with a primary amine as base to give phenazine-l,3-diol 5,10-dioxide.Phenazine-2,3-diol 5,10-dioxides are also synthesized by the reaction of benzene-1,2,4-triol with 6-substituted benzo-furoxans. ... 

Phenazine-1.6-diol 5,10-dioxide (iodininc) can be easily prepared from phenazine-l,6-diol by peroxyacid oxidation. Oxidation of 1,6-dimethoxyphenazinc (3) with 3-chloroperoxybenzoic acid affords 1,6-dimethoxyphenazine 5-oxide (4) and 1. b-dimethoxyphenazine 5,10-dioxide... 

Several phenazine derivatives, e.g. phenazin-2-ol, phenazine-l-carboxylic acid, 2-hydroxy-phenazine-1-carboxylic acid, phenazine-2,3-diol, and 2,3-dihydroxyphenazine-l-carboxylic acid have been isolated from Pseudomonas aureofaciens. 

The acidophilic bacterium Pseudomonasphenazinium has been observed to produce the water-insoluble purple pigment iodinine (phenazine-1,6-diol 5,10-dioxide). 

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