Hydroxy quinolines, synthesis

Quinoline-4-carboxylic acid, 3-hydroxy-Pfitzinger synthesis, 2, 446 Quinoline-4-carboxylic acid, 2-methyl-synthesis, 2, 475... 

The utility of [TcOCU] in Tc chemistry is demonstrated by the first synthesis of 8-hydroxy-quinoline (8-Hox, (126)) complexes of technetium in 1984. Ligand (126) is usually one of the first choices to explore the coordination chemistry of an element, but it was as late as 1984 when the first complex with Tc was prepared. It was known that the reaction of [ Tc04] with 8-Hox leads to complexes with high brain uptake, and it was therefore important to define the structure of the active species. This sequence of events is very typical for technetium chemistry. Nuclear medicinal experiments indentify a Tc species with useful biological behavior, which prompts investigations into the basic coordination chemistry to identify the structure of the Tc... 

Carbostyril.—If in the Baeyer and Drewsen synthesis cinnamic acid is used instead of cinnamic aldehyde the or//fo-amino derivative, by loss of water, yields a hydroxy quinoline known as carbostyril. 

Additionally, Rivkin and co-workers synthesized a variety of 4-hydroxy-3-phenylquinolin-2-(l//)-ones under solvent free microwave conditions using an activated arylmalonate <06TL2395>. Reacting the desired substituted aniline with di-(2,4,6-trichlorophenyl)-2-phenyl-malonate at 250 °C with microwave irradiation for 15 min resulted in a variety of 4-hydroxy-3-phenylquinolin-2-(l//)-ones in good yields. They also demonstrated the utility of this method in the synthesis of type I fatty acid synthase inhibitors <06BMCL4620>. Kumar et al. have reported a variation of the Friedlander quinoline synthesis. They highlight the use of CeClj THjO as a reusable catalyst in the reaction of 2-... 

SYNTHESIS OF (lS,2S,4S,5R,l R)-l-(ANTHRACEN-9-YLMETHYL)-5-ETHYL-2- [HYDROXY (QUINOLIN-4-YL)METHYL] -1 -AZONIABICYCLO[2.2.2]OCTANE BROMIDE... 

Syntheses of the antibiotic compounds deoxynybomycin (100) and nybomycin (102) as well as related heterocyclic compounds have been described (Scheme 7). The 8-hydroxy-2-quinolone (97), readily prepared from o-anisidine in three steps, was converted into the fused oxazoline-quinoline derivative (98) by successive nitration, reaction with dibromomethane, and hydrogenation. Adaptation of the Doebner-von Miller quinoline synthesis to (98) provided the tetracyclic product (99), which upon methylation and oxidation gave deoxynybomycin (100) in 0.83% overall yield from o-anisidine. The key intermediate... 

Everson R.J. and Parker H.E. 1974. Zinc binding and synthesis eight-hydroxy-quinoline-agarose, Bioinorg. Chem., 4, 15. 

Two related reactions of quinoline construction, the Pfitzinger and Niementowski reaction, can be considered as extensions of the Friedlander synthesis. Niementowski reaction uses anthranilic acid for the synthesis of 4-hydroxy quinolines, and Pfitzinger reaction applies substituted isatins as precursors for ort/io-aminophenylglyoxylic acid, which is used as the condensation component with carbonyl compounds to produce 4-carboxylic acid quinolines. 

Hydroxy-quinoline carboxylates, prepared using the Could-Jacobs reaction, have also been frequently used as precursors for the synthesis of biologically interesting quinoline compounds. For example, the syndiesis of... 

This reaction was first reported by Knorr in 1886. It is the synthesis of 2-hydroxyquinolines via the cyclization and dehydration of an anilide intermediate condensed from )0-ketoesters and anilines at a relatively high temperature. Right after this report, Conrad and Limpach also reported a similar reaction between anilines and )0-ketoesters but at low temperatures, which resulted in the formation of 4-hydroxy quinolines from the intermediate of alkyl crotonate. Thus this reaction is known as the Knorr synthesis, Knorr-Limpach method, Knorr cyclization, Conrad-Limpach-Knorr reaction, or Knorr quinoline synthesis. It has been reported that the formation of an alkyl crotonate intermediate is favored at moderate or low temperature in the presence of iodine or an acid catalyst, whereas intermediate anilide is formed at high temperatures. ... 

A modification of the Niementowski quinoline synthesis for the preparation of 4-hydroxyquinolines bearing an arylketone at the 3-position was reported by Wang et al Reaction of 36 with 37 afforded 4-hydroxyquinoline 38. This 4-hydroxy quinoline with a 2-thiomethyl... 

Nadaraj et al. carried out MW-assisted synthesis of 4-methyl-2-hydroxy-quinolines (46) and 2-methyl-4-hydroxyquiniolines (47) from aniline and ethyl acetoacetate (Scheme 6.19) [58],... 

Heravi et al. (2006) have studied the synthesis of 2-phenyl-3-hydroxy-quinolin-4(lH) under microwave irradiation in solventless system. It was a two-step synthesis. Anthranilic acid, phenacyl bromide and potassium carbonate were exposed under microwaves in solventless media to produce phenacyl anthranilate (within 2 min), where as the same product was obtained in 1 h under conventional heating. Final product 2-phenyl-3H-benz-[e] [1,4] oxazepin-5-one was prepared in very short time of only 2 min when phenacyl anthranilate was treated further with polyphos-phoric acid supported on silica gel. 

Conra.d-Limpa.ch-KnorrSynthesis. When a P-keto ester is the carbonyl component of these pathways, two products are possible, and the regiochemistry can be optimized. Aniline reacts with ethyl acetoacetate below 100°C to form 3-anilinocrotonate (14), which is converted to 4-hydroxy-2-methylquinoline [607-67-0] by placing it in a preheated environment at 250°C. If the initial reaction takes place at 160°C, acetoacetanilide (15) forms and can be cyclized with concentrated sulfuric acid to 2-hydroxy-4-methylquinoline [607-66-9] (49). This example of kinetic vs thermodynamic control has been employed in the synthesis of many quinoline derivatives. They are useful as intermediates for the synthesis of chemotherapeutic agents (see Chemotherapeuticsanticancer). 

Friedlander synthesis, 2, 445 Quinoline, alkenyl-1,2-dihydro-disproportionation, 2, 369 Quinoline, 2-alkoxy-reactions, 2, 351 Quinoline, 4-alkoxy-reactions, 2, 351 Quinoline, 2-alkoxy-4-hydroxy-synthesis... 

Quinolin-2-one, 3-cyano-4-hydroxy-synthesis, 2, 428 Quinolin-2-one, 3,4-dialkyl-Knorr synthesis, 2, 425 Quinolin-2-one, dihydro-Camps synthesis, 2, 418 synthesis, 2, 402 from benzazepinones, 2, 506 from indanone oxime, 2, 487 from indanones, 2, 488 by intramolecular Friedel-Crafts reactions, 2, 421... 

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