6-Methoxy-4:7-phenanthroline

A few extensions of the Conrad-Limpach synthesis have been applied to the synthesis of 4,7-phenanthrolines. Unlike o-phenylenediamine, which gives a quinoxaline derivative, p-phenylenediamine reacts with excess of ethyl ethoxalylpropionate to give an intermediate bisanil, which cyclizes in hot diphenyl ether to afford 3,8-dicarboethoxy-l,10-dihydroxy-2,9-dimethyl-4,7-phenanthroline in high yield.237 With diethyl ethoxymethylenemalonate as condensing agent, 6-amino-8-methoxy-quinoline has been converted into 2-carboethoxy-l-hydroxy-6-methoxy-4,7-phenanthroline.238 A related condensation affording 1-... 

Methoxy-4 7-phenanthroline Nitric acid Caustic soda... 

Phen phenanthrollne, 4-methoxy phenanthroline, 2-methyl phenanthroline, 4-methyl phenanthroline, 9-phenyl phenanthroline Miscellaneous 2,2-bipyridine, 8-qulnolinol, IDAA, MIDA, EDTA, dlplvaloylmethane... 

Trihydrazinecobalt(II) nitrate, 4205 Trihydrazinenickel(II) nitrate, 4592 Tris(2,2/-bipyridine)chromium(II) perchlorate, 3874 Tris(2,2/-bipyridine)silver(II) perchlorate, 3873 Tris(2,3-diaminobutane)nickel(II) nitrate, 3589 Tris(l,2-diaminoethane)chromium(III) perchlorate, 2619 Tris(l,2-diaminoethane)cobalt(III) nitrate, 2622 Tris(l,2-diaminoethane)ruthenium(III) perchlorate, 2621 Tris(4-methoxy-2,2/bipyridine)ruthenium(II) perchlorate, 3886 Tris(3-methylpyrazole)zinc sulfate, 3540 Tris(l,10-phenanthroline)cobalt(III) perchlorate, 3890 Tris(l,10-phenanthroline)ruthenium(II) perchlorate, 3889... 

The oxidation of 1,7-phenanthrolines containing a hydroxy, methoxy, or amino group in the 5- or 6-position to 1,7 phenanthroline-5,6-dione (51) by nitric acid has been patented.249 250 Its monosemicarbazone has also been patented.251 l,7-Phenanthroline-5,6-dione (51) gives the diepoxide (52) on reaction with diazomethane.226... 

There has been considerable interest in the preparation of 4,7-phenanthroline-5,6-dione and its relatives due to their antibacterial activity. Patents225,249, 250,256,257 have appeared covering the oxidation of 5- or 6-substituted hydroxy-, methoxy-, or amino-4,7-phenanthrolines to... 

The nitration of l,4-dihydro-5-methoxy-2-trifluoromethyl-4-oxo-l,10-phenanthroline gives a nitrated product, presumably the 6-nitro derivative, along with the corresponding 5,6-dione.38... 

Dioxo-l,4,7,10-tetrahydro-l,10-phenanthroline (72) with dimethyl sulfate gives l,4-dihydro-7-methoxy-l-methyl-4-oxo- 1,10-phenanthroline (73) rather than a quaternary salt, steric hindrance presumably preventing alkylation of both nitrogens.203 A related alkylation has also been reported.295 1,2,3,4-Tetrahydro-1,10-phenanthrolines similarly form 1-alkyl derivatives rather than 10-alkyl quaternary salts with alkyl halides.38 The rate of methylation of 1,10-phenanthroline with methyl iodide in dimethyl sulfoxide has been studied,296 and the polaro-graphic reduction of 1 -methyl- 1,10-phenanthrolinium iodide was reported.286... 

There is a difference in the ease with which the two chlorine groups in 4,10-dichloro-l,7-phenanthroline are replaced by nucleophiles. For example, the 10-chloro substituent reacts with sodium ethoxide five hundred times faster than the 4-chloro substituent. Consequently, 4-chloro- 10-ethoxy, 4-chloro- 10-methoxy-, 4-chloro- 10-anilino, and 4-chloro-10-hydroxy-1,7-phenanthrolines can be prepared from 4,10-dichloro-l,7-phenanthroline.97, 171,172,336 The exceptional reactivity of the 10-chloro group is attributed to relief of strain in the transition state in its reaction with nucleophilic reagents.336 With excess of the nucleophilic reagents, both chlorines in 4,10-dichloro-l,7-phenanthroline are replaced.171, 172,336... 

Several further examples have been reported of the replacement of hydroxyl (or oxo) substituents in 1,10-phenanthrolines by halogens with phosphorus halide reagents.38 96 196,198,213 213,219,293,340-342 4-Ethoxy-7-hydroxy-l,10-phenanthroline reacts normally with diazomethane to afford 4-ethoxy-7-methoxy-1,10-phenanthroline.203... 

The bromine group in 4-bromo-5-methoxy-2-trifluoromethyl-l,10-phenanthroline has been replaced by lithium with w-butyllithium and the lithio derivative reacted with pyridine 2-aldehyde.215... 

Further examples of the conversion of methoxy-l,10-phenanthrolines into hydroxy-1,10-phenanthrolines by the usual hydrogen halide reactions have been reported.98,214 4,7-Bis-phenoxy-1,10-phenanthroline is converted into 4,7-diamino-1,10-phenanthroline by ammonium chloride at high temperatures.98... 

The synthesis and near-infrared photoluminescence of [Os(bpy)2(3,8-diarylethynyl-l,10-phenanthroline)]2+ complexes (AEphen A = methoxy-phenyl, biphenyl, nitrophenyl) have recently been reported. These phenan-throline complexes exhibit emission in the 790-830 nm region. The nitro-phenylethynyl derivative exhibits no room temperature luminescence, presumably because of intramolecular electron transfer quenching [22],... 

Oxidation of (1) with commercial bleach (hypochlorite) in the presence of a phase transfer catalyst43,44 gives the [l]-5,6-epoxide (10), which is quite versatile in the preparation of a variety of 5-subsituted-phenanthrolines, including cyano-, hydroxy-, dimethylamino-, aza-18-crown-6-, and methoxy-[l].45 Under acidic conditions, this reaction permits the direct conversion of (1) to 7.44 46... 

Several examples have been reported of the preparation of 4,7-phenanthrolines from substituted 6-aminoquinolines by the Skraup and related reactions. In this way, 5-methoxy-, 5-chloro-, 3-methyl-6-methoxy-, l-methyl-, and l,2,3,4-tetrahydro-4-methyl-4,7-phenanthrolines have been synthesized while improvements have been made to the synthesis of the 3-methyl derivative. The Skraup reaction has also been applied to quaternary salts of 6-aminoquinolines. For example, 5-chloro-4-methyl-4,7-phenanthrolinium iodide (36) was obtained from the methiodide of 6-acetamido-8-chloroquinoline (35). Cyclizations starting from aminocarbostyrils have also been reported. Thus, 6-amino-1-methylcarbostyril (37) was condensed with paraldehyde in the presence of concentrated hydrochloric acid to afford 3,4-dihydro-4,8-dimethyl-3-oxo-4,7-phenanthroline (38), while under Skraup conditions, with glycerol as condensing agent, 6-amino-4-methylcarbostyril afforded 3,4-dihydro- l-methyl-3-oxo-4,7-phen-... 

Phanquinone. 4,7-Phenanthroline-S,6-dione 4,7-phenanthroline-5,6-quinone 5,6-dioxo-S,6-dihydro-4,7-phenanthroline phanchinone, phanquone, Ciba 1)925 En-tobex. C,jH(N20, mol wt 210.18. C 68.57%, H 2.88%, N 13.33%, 6 15.23%. Prepd from 5,(6) -methoxy -4,7 -phen-anthroline Druey, Schmidt, Helv. Chim. Acta 33, 1080... 

In the development of pyridone fused acridines, Kennedy et al. used a sulfoxide-based route to produce 3,7-dimethyl-5-methoxy-l-phenylthio-l,2,3,4-tetrahydro-2-oxobenzo[6][l,8]phenanthroline 118 (Scheme 23) [91-JCS(P1)2499]. 

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