Quinolines pyridyl

While pyridine and quinoline N-oxides do not react directly with enamines, they have been found to form a-pyridyl and 2-quinolinyl-2 -cyclohexanones in good yields after prior acylation (371,372). 

Analogous to the selectivity observed for the conversion of 48 into 50, pyridyl 51 formed enamine 52 which underwent cyclization to give 4-pyridyl-substituted quinoline 53. Again, imine formation first occurs on the less hindered ketone and subsequent cyclization on the more reactive carbonyl occurred in high yield. ... 

In the search for new fluorometric reagents for trace metal determinations, ferroin-type compounds, namely 2-(2-pyridyl)-2//- and 2-(3-isoquinolyl)-3//-imidazo[4,5-/i]quinolines, and their silver, lead, and zinc chelates were tested for luminiscence in aqueous ethanol solutions at various pH values (80TAL1021). 

Bromoquinolines behave in the Suzuki reaction similarly to simple carbocyclic aryl bromides and the reaction is straightforward. Examples include 3-(3-pyridyl)quinoline (72) from 3-bromoquinoline (70) and 3-pyridylboronic acid (71) (91JOC6787) and 3-phenyl-quinoline 75 from substituted 3,7-dibromoquinoline 73 and (2-pivaloylaminophenyl)boronic acid 74 (95SC4011). Notice that the combination of potassium carbonate and ethanol resulted in debromination at the C(7) position (but the... 

Mn(2-02CC6H40H)2,2,469 MnC14H12Br2N20 MjiBr2(H20) 2-(2-pyridyl)quinoline, 4,24 MnCl4H12N202... 

Amine complexes stabilized with phosphine ligands of the type [AuL(PR3)]+ have been obtained for L = bipy,2310 phen,2310,231 quinoline,23 1 acridine,2311 benzo[h]quinoline,2311 naphthyr-idine (388)2311 2,2 -biquinoline,2311 di-2-pyridyl-ketone,2311 di-2-pyridylamine,2311 2-(2-pyridyl)-benzimidazole, 2311 ferrocenylpyridine, 2-nitroaniline,2312 4-methoxyaniline,2312 NHPh2, 2 NHEt2,2312 NMe3,2312 quinuclidine,2313 NEt3,2314 2-aminothiazoline,2315 histidine,2316... 

Other complexes with bridging N,S ligands are the 1,3-dimethyl-8-thioxantine derivative [Au2(/u-N,S) /u-PMe2(CH2)2PMe2 ],3149 or with quinoline thiolates [Au5(/u-SQuin)3(//-dppm)2]2+ (604)3150 deprotonated ethylenethiourea [Au4(etu-H)4] (605)3151 or with 2-methoxyphenyl-imino(2-pyridyl)methylthio derivatives as [Au SC(Py)=NR) (PPh3)].3152... 

This is the case for the [Fe N6]2+ derivatives of 40 [50], 41 [51], 42 [52] and is consistent with the behaviour of the pyridyl-quinoline or 6-methyl-bipyridine systems. The incorporation of five-membered heterocyclic ring systems in this way could be readily achieved but does not seem to have been exploited in the generation of the crossover situation. 

Recently, a series of pyridine- and quinoline-derived catalysts 31 (Fig. 29.18) have been developed. Ligands 31a-k were obtained by reduction of pyridyl ke-... 

Rosoxacin was prepared in 47% yield by the cyclization of diethyl iV-ethyl-iV-[3-(4-pyridyl)phenyl]aminomethylenemalonate in polyphosphoric acid at 165°C for 1 hr, followed by hydrolysis of the corresponding quinoline-3-carboxylate (85 USP4533735). 

Rosoxacin was obtained in 16% yield by the cyclization of isopropylidene N-ethyl-N-[3-(4-pyridinyl)phenyl]aminomethylenemalonate in pol-yphosphoric acid at 125-137°C for 30 min [77JAP(K)116460], Isopropylidene 2-pyridyl- and 2-quinolinylaminomethylenemalonates (1195) were cyclized in boiling phosphoryl chloride by the action of poly-phosphoric acid at I35-140°C. When the formation of hydrogen chloride gas ceased, the reaction mixtures were treated with an alcohol or water to afford the corresponding alkyl 4-oxopyrido[ 1,2-a]pyrimidine-3-carbox-ylates or alkyl 1 -oxopyrimido[ 1,2- ]quinoline-2-carboxylates (1196, R2 = alkyl) in 51-96% yields or to afford carboxylic acids (1196, R2 = H) in 64-84% yields (79MIP2 80MIP3 84S152). 

HETE (138) is known to inhibit 5-LO [334]. A group at Revlon created a series of combined 5-LO inhibitors/LT antagonists derived conceptually from the structure of 15-HETE. REV 5901A (139) [335], the best of the series, inhibited 5-HETE release from rat ISN (0.12 //M) and was fairly selective with respect to CO and 12-LO inhibition. The quinoline could be replaced by another lipophilic aromatic group, but potency decreased (naphthalene was 40-fold less potent, and substituted phenyl was 5- to 20-fold less active). Pyridines were active but also less potent 2-pyridyl was only 4-fold less active, while 3- and 4-pyridyl were 20-fold weaker. Ortho-and pnra-substituted phenylene groups were less active. Elimination of the side-chain hydroxyl to the olefin caused a loss of activity, as did the use of shorter alkyl chains. 

The electrochemical properties of another series of Cu(I) complexes, based on substituted bipyridine and quinoline derivatives, have been also investigated68 (Fig. 17.31). To stabilize the Cu(I) oxidation state of Cu(I) polypyridine complexes, electron-withdrawing substitutents like esters have been considered. The same effect was also obtained with pyridyl-quinoline and biquinoline complexes, thanks to the increased 7i-accepting properties of the quinoline condensed aromatic ring. 

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