Hydro quinolines

Hydrogenated quinolines. The hydrogenated quinolines which are analogous to piperidine, the hydrogenated pyridine, are also known. The methyl amino and ethyl amino derivatives of tetra-hydro quinoline are known as kairolines and are antipyretics. They exert a toxic action on the blood corpuscles and are therefore not used in medicine. 

Synthesis of chiral heterocycles by domino organocatalytic processes has also been intensively studied. In particular, various benzo-fused heterocycles, such as chiral chromans, " thiochromanes, hydro-quinolines, dihydropyranes, or thiopyranes were investigated. These organocatalytic sequence were typically initiated by a hetero-Michael addition of a sulfur, oiqrgen or nitrogen nucleophile, which triggers the formation of an enolate/enamine that adds to the ortho electrophile terminating the cascade reaction. An elimination step or an additional cyclisation step follows (Scheme 8.25). 

ScHRAMEt P., Xu L., Knapp G. and Michaeijs M. (1993) Multielemental analysis in biological samples by online pre-concentration on 8-hydro -quinoline—cellulose microcolumn coupled to simultaneous ICP-AES, Fresenius J. Amd. Chem. 345 600-606. 

Both objectives have been met by designing special hydrogenation catalysts The most frequently used one is the Lindlar catalyst, a palladium on calcium carbonate combi nation to which lead acetate and quinoline have been added Lead acetate and quinoline partially deactivate ( poison ) the catalyst making it a poor catalyst for alkene hydro genation while retaining its ability to catalyze the addition of H2 to the triple bond... 

Methyl-37/-indoles react with 2 equiv of diethyl malonate in hot diphenyl ether to give pyranoindolizines such as 125. However, under the same conditions, 2-methvl-2.3-di hydro-1 //-indoles give the regioisomeric pyrrolopyrano-quinolines, for example, 126 (Scheme 35) <2003JHC297>. 

Tertiary benzamides whose N-atom is part of a cyclic system can also be hydrolyzed metabolically as shown in the following examples. The hydrolysis of the amide group in 6-[4-(3,4-dimethoxybenzoyl)piperazin-l-yl]-3,4-di-hydro-1 //-quinolin-2-one (OPC-8212, 4.85), an inotropic agent, occurred in rats, mice, dogs, monkeys, and humans [54], After oral administration to rats, both products of hydrolysis, namely 3,4-dimethoxybenzoic acid (veratric acid, 4.86) and piperazine-l//-quinolin-2-one (4.87) were detected in the plasma, urine, and feces. 

ZN(C)153, 00ZN(C)323, 00ZN(C)857, 01MI2, 01MIP4, 01TL5849). 5-Amino-8 3)-d i hyd roxy-2,3-d i hydro-1 //-py nmido[l,2-<2]quinoline-3-carboxyHc acid moiety 4 was also identified as a chromophoric moiety of certain... 

Pyridine and its derivatives react with 1,3-pentadienes forming cyclic products. This type of cyclization was observed by the authors of 95JFC(72)49. They showed that in the reaction of (Z)-1,1,2,5,5,5-hexafluoro-4-phenyl-3-trifluoromethyl-1,3-pentadiene 117 with pyridine the products are [ S,9aR]- and [lS,9tfS]-3-fluoro-9<2-hydro-l,2-bis(trifluoro-methyl)-l-phenyl-4//-quinolizin-4-ones 118 and 119 with 54 and 21% yields, respectively. The structure of the compounds was confirmed by X-ray analysis. Similarly, the reaction of (Z)-l,l,2,5,5,5-hexafluoro-4-iodo-3-trifhioromethyl-l,3-pentadiene 120 with 4-substituted pyridines gives the derivative of 4//-quinolizin-4-one 121 with quinoline, the product is derivative 122. 

Hydroxy quinoline 8 hydroxy quinoline sulfate, oxime copper 3 Hydroxy tetra hydro furan furyloxyfen... 

The pyridine ring is easily reducible. Hydropyridines are formed from pyridine and its derivatives, and piperidines by complete hydration. Quinoline and acridine are also easily converted into hydro-compounds. 

Problem 20.38 Prepare (a) 3-aminopyridine from jS-picoline, (b) 4-aminopyridine from pyridine, (c) 8 -hydro-xyquinoline from quinoline, (d) 5-nitro-2-furoic acid from furfural, (e) 2-pyridylacetic acid from pyridine. A... 

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