Quinolinium salts, synthesi

Finally, the importance of quinolinium salts to dye chemistry accounts for the long, productive history of their synthesis. The reaction of A/-methylformanihde with ketones, aldehydes, ketone enamines, or enol acetates in phosphoryl chloride leads to high yields of /V-methylquinolinium salts (60). 

Pyrimido[4,5-6]quinolinium salts pseudo bases - ring opening, 3, 208 Pyrimido[4,5-6]quinolinium salts, 4-chloro-hydrolysis, 3, 214 Pyrimido[4,5-6]quinolinones synthesis, 3, 228 Pyrimido[4,5 -6]quinolin-5-ones synthesis, 3, 221-222 Pyrimidothiadi azoles reactions, 6, 533 Pyrimidothiazines synthesis, 4, 527 Pyrimidothiazinones mass spectra, 2, 23... 

Quinolinium 2-dicyanomethylene-1,1,3,3-tetracyanopropanediide dimensions, 2, 110 Quinolinium iodide, 1-alkyl-Ladenburg rearrangement, 2, 300 Quinolinium iodide, 1-methyl-Ladenburg rearrangement, 2, 300, 335 Quinolinium iodide, [l-methyl-4-[3(5)-pyrazolyl]-blood sugar level and, 5, 291 Quinolinium perchlorate, 1-ethoxy-hydroxymethylation, 2, 300 Quinolinium perchlorate, 1-methyl-nitration, 2, 318 Quinolinium salts alkylation, 2, 293 Beyer synthesis, 2, 474 electrophilic substitution, 2, 317 free radical alkylation, 2, 45 nitration, 2, 188 reactions... 

Quinolinium salts, l-(4-alkoxyphenyl)-2-methyl-synthesis, 2, 475 Quinolinium salts, aryl-Skraup synthesis, 2, 467 Quinolinium salts, 4-chloro-synthesis... 

The Reverse Vilsmeier Approach to the synthesis of quinolinium salts is discussed in Meth-Cohn, O. Taylor, D.L. Tetrahedron 1995, 51, 12869. 

Quinolinium salts have been used in the synthesis of hydroxyquinoline derivatives with KO/Bu in the presence of ultrasound <95SC(25)2999>. Quinolinium salts have been used in cycloaddition reaction with butadiene derivatives to give acridine compounds (Scheme 38) <95SL938>. 

Because of the ease of its removal the hydroxymethyl group can even be used for synthesis of phospha analogs of cyanine dyes 2-chloro-benzothia-zolium or -quinolinium salts are treated with 0.5 equivalent of tris(hydroxy-methyl)phosphine in the presence of 1.5 equivalents of a tertiary amine 228... 

Related transformations include the photodehydrocyclization of the perchlorate salt (34) to give the 7//-indolo[l,2-a]quinolinium salt (35), the synthesis... 

Scheme 95 Synthesis of 2-methoxycarbonyl-substituted thieno[2,3-()]quinolinium salts [141]...

In 1923, Mills introduced thiazole for the first time in the synthesis of methine dyes through a somewhat indirect route. In order to demonstrate the 2,4 -cyanine mechanism of formation by quinoline and quinaldine quaternary salts reacting together, Mills used other pairs of quaternary salts as 2-methylthiazolium with either quinolinium or benzothiazolium (42, 43). 

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