I-methyl-4-quinolone

Recently kinetic data have become available for the nitration in sulphuric acid of some of these hydroxy compounds (table 10.3). For 4-hydroxyquinoline and 4-methoxyquinoline the results verify the early conclusions regarding the nature of the substrate being nitrated in sulphuric acid. Plots of log Q against — (Lf + logioflHao) fo " these compounds and for i-methyl-4-quinolone have slopes of i-o, i-o and 0-97 at 25 C respectively, in accord with nitration via the majority species ( 8.2) which is in each case the corresponding cation of the type (iv). At a given acidity the similarity of the observed second-order rate constants for the nitrations of the quinolones and 4-methoxy-quinoline at 25 °C supports the view that similarly constructed cations are involved. Application of the encounter criterion eliminates the possibilities of a... 

The case of i-methyl-4-quinolone is puzzling. The large proportion of the 3-nitro isomer formed in the nitration (table 10.3 cf. 4-hydroxyquinoline) might be a result of nitration via the free base but this is not substantiated by the acidity dependence of the rate of nitration or by the Arrhenius parameters. From r-methyl-4-quinolone the total yield of nitro-compounds was not high (table ro.3). 

A number of simple quinolines and quinolones have been isolated from various rutaceous plants, e.g., from angostura bark (Volume III, p. 80) and from Lunasia amara Blanco (Volume VII, p. 241 this chapter Section IV,A). The leaves of Haplophyllum dubium Eug. Kor (15, 16) contain dubamine (mp 96°-97°) which has been identified (17) as 2-(3,4-methylenedioxyphenyl)quinoline (I). Ruta graveolens L. contains, in addition to furoquinolines, the alkaloids graveoline (mp 205°) (18,19), and graveolinine (mp 115°-116°) (20), the latter (II) is also found in L. amara, and the former is the related l-methyl-4-quinolone (III). 

A. Kolbe (3), working with a specimen of Greshoff s material, showed the alkaloid to be l-methyl-4-quinolone (I). New analyses of the alkaloid indicated the formula CioHtON, and showed the presence of an AT-methyl group. By reduction with sodium and alcohol, or better by electrolytic reduction at a lead cathode, an oxygen-free base, CioHuN, was obtained, which was identified as l-methyl-l 2 3 4-tetrahydroquinoIine (II) by comparison of its picrate (m.p. 122°) with a synthetic specimen. 

The enamine adducts formed in the reaction of aromatic amines with DMAD have been found to undergo cyclization leading to heterocyclic compounds, and the mode of these reactions is to a considerable extent influenced by the reaction conditions, the catalyst employed, and also the nature of the functional groups present in the starting amine. The reaction of aniline with methyl propiolate in presence of cuprous acetate, for example, is reported to give a mixture of 2(lH)-quinolone (I) and 4(l//)-quinolone (2) [Eq. (I)].11 On the other hand, dimethyl anilinofumarate (3), formed from aniline with DMAD, undergoes... 

Echinopsine, l-Methyl-4(lH).quinolinone 1-metkyl-4Echinops ritro L. and other spp of Echinops, Campositae Greshoft, Rec. Trav. Chim. 19, 360 (1900) Ban kovskii et al, Hold. Akad. Nauk SSSR 148, 1073 (1963). Structure Spath, Kolbe, Monotsh. 43, 469 (1923). Synthesis Kondo, Ikawa, /. 

Iridium complex-catalyzed cyclization of an Af-arylcarbamoyl chloride with an alkyne has been reported by Tsuji and coworkers [153]. In a typical example, Af-methyl-Af-phenylcarbamoyl was reacted with 5-decyne and a catalytic amount of [IrCl(cod)]2 (2.5mol%) and additional cod (30mol%) in refluxing o-xylene for 20 h to give 3,4-dimethyl-l-methyl-2-quinolone in 92% yield (Scheme 11.5). During this reaction, no indole product formed by decarbonylation was observed. This reaction is proposed to proceed by oxidative addition of Af-arylcarbamoyl chloride to Ir(I), giving a carbamoyl chloroiridium(III) species. Subsequently, the formation of a five-membered iridacycle by ortho-aryl C-H activation followed by insertion of the alkene and reductive elimination produces the 2-quinolone derivative. 

Alcohols can be converted into halides if lithium halides (F, Cl, Br, I) or Mel are used in the presence of TPP/DEAD. Kim and Kim were interested in the preparation of (5)-(-)-7,8-difluoro-3,4-dihydro-3-methyl-2//-1,4-benzoaxine (223), a key intermediate for the synthesis of the commercially available quinolone antibiotic levofloxacin. Initial attempts to cyclize 222 under the standard Mitsunobu conditions employing the TTP/DEAD conditions failed to give acceptable yields even when the reaction was refluxed for 1 h in benzene or acetonitrile. Addition of several equivalents of zinc chloride gave the desired cyclized product, some chlorinated intermediate, and none of the DEAD adduct 224. The DEAD adduct was the major product under the standard Mitsunobu conditions. The stereochemistry of the obtained products, which indicates retention of stereochemistry, suggests that the reaction proceeded via a chloride intermediate. 

A-Alkylation of amides and amines and dehydrative -alkylation of secondary alcohols and a-alkylation of methyl ketones " have been carried out by an activation of alcohols by aerobic oxidation to aldehydes, with copper(II) acetate as the only catalyst. A relay race process rather than the conventional borrowing hydrogen-type mechanisms has been proposed for the aerobic C-alkylation reactions, based on results of mechanistic studies. A Winterfeldt oxidation of substituted 1,2,3,4-tetrahydro-y-carboline derivatives provides a convenient and efiflcient method for the synthesis of the corresponding dihydropyrrolo[3,2-fc]quinolone derivatives in moderate to excellent yields. The generality and substrate scope of this aerobic oxidation have been explored and a possible reaction mechanism has been proposed. Direct oxidative synthesis of amides from acetylenes and secondary amines by using oxygen as an oxidant has been developed in which l,8-diazabicyclo[5.4.0]undec-7-ene was used as the key additive and copper(I) bromide as the catalyst. It has been postulated that initially formed copper(I) acetylide plays an important role in the oxidative process. Furthermore, it has been postulated that an ct-aminovinylcopper(I) complex, the anti-Markovnikov hydroamination product of copper acetylide, is involved in the reported reaction system. Copper(I) bromide... 

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