Quinoline acetic acid

Reagents (i) NaBH4, MeOH (ii) TsOH, SiOi, C6Hg (iii) Quinoline, acetic acid (iv) DMF, C5H5N, Pb(OAc)4... 

HYDROGENATION, TRANSFER Hexafluoroantimonic acid. Palladium black. Tris-(aquo)hexa-M-acetate-M3 -oxotriruthenium(IlI,IlI,Ill) acetate. Tris(triphenylphos-phine)chlororhodium. Tris(triphenylphosphine)ruthenium(Il) dichloride. HYDROLYSIS, ESTERS Quinoline-Acetic acid. 

Queen butterfly pheromone, 79 Queen s substance, 217 Quinine, 80, 501 Quinol acetates, 314-315 QuinoUne, 383, 498, 619, 621 Quinoline—Acetic acid, 501 Quinolineearboxylic acids, 450 p-Quinols, 428-429 Quinomycin, 193 Quinones, 120, 121, 555, 556 Quinonimines, 513... 

A mixture of methyl 0-methylpodocarpate, quinoline, and acetic acid refluxed 40 hrs. under a slow stream of Ng -> 0-methylpodocarpic acid. Y 84%. -Acetates of prim, alcohols are not affected by prolonged heating with the quinoline-acetic acid mixture. F. e. s. G. Aranda and M. Fetizon, Synthesis 1975, 330. 

The mixed bases are boiled with an acetic acid-acetic anhydride mixture to convert the aniline into acetanilide. The product is poured into water, when the acetanilide crystallises out while the quinoline remains in solution as quinoline acetate. The acetanilide is filtered off, and the filtrate made alkaline and steam-distilled. 

In many instances, beginning a synthesis with quinoline N-oxide [1613-37-2] faciHtates the preparation of difficult compounds. Quinoline is converted to the N-oxide using hydrogen peroxide in acetic acid, and later reduced to the substituted quinoline. Warm mixed acid gives 4-rutroquinoline... 

Reduction. Quinoline may be reduced rather selectively, depending on the reaction conditions. Raney nickel at 70—100°C and 6—7 MPa (60—70 atm) results in a 70% yield of 1,2,3,4-tetrahydroquinoline (32). Temperatures of 210—270°C produce only a slightly lower yield of decahydroquinoline [2051-28-7]. Catalytic reduction with platinum oxide in strongly acidic solution at ambient temperature and moderate pressure also gives a 70% yield of 5,6,7,8-tetrahydroquinoline [10500-57-9] (33). Further reduction of this material with sodium—ethanol produces 90% of /ra/ j -decahydroquinoline [767-92-0] (34). Reductions of the quinoline heterocycHc ring accompanied by alkylation have been reported (35). Yields vary widely sodium borohydride—acetic acid gives 17% of l,2,3,4-tetrahydro-l-(trifluoromethyl)quinoline [57928-03-7] and 79% of 1,2,3,4-tetrahydro-l-isopropylquinoline [21863-25-2]. This latter compound is obtained in the presence of acetone the use of cyanoborohydride reduces the pyridine ring without alkylation. 

Imides (e.g. phthalimide) can be purified by conversion to their potassium salts by reaction in ethanol with ethanolic potassium hydroxide. Hie imides are regenerated when the salts are hydrolysed with dilute acid. Like amides, imides readily crystallise from alcohols and, in some cases (e.g. quinolinic imide), from glacial acetic acid. 

Acetyl chloride [75-36-5] M 78.5, b 52 , d 1.1051, n 1.38976. Refluxed with PCI5 for several hours to remove traces of acetic acid, then distd. Redistd from one-tenth volume of dimethylaniline or quinoline to remove free HCl. A.R. quality is freed from HCl by pumping it for Ih at -78 and distg into a trap at -196 . 

Using different mono- and diketones in acetic acid (at room temperature) afforded the following products from benzophenone, 2,2-diphenyl-2//-imid-azo[4,5-/]quinoline from dibenzylketone, the 2-benzyl-imidazo[4,5-/]quino-line and from 2,4-pentanedione, 2-methyl-imidazo[4,5-/]quinoline. Cyclohexanone under reflux gave 2-n-pentyl-, whereas at room temperature it afforded the. s pira[cyclohexane-l,2 ]-(2//)-imidazo[4,5-/]quinoline 108 (R R =(CFl2)5) (86UC527). 

Alkylation of the cyclization product 115 and the following hydrolysis gave 9-alkyl substituted 6-oxo-6,9-dihydroimidazo[4,5-/i]quinoline-7-carboxylic acid derivatives 119, compounds useful as antibacterials (no data) [80JAP(K)1], 4(7)-Aminobenzimidazole can react with 1,3-diketones as a bidentate nucleophile, but with 2,4-pentanedione in glacial acetic acid it gives a Combes product, l//-6,8-dimethylimidazo[4,5-/i]quinoline 120, accompanied by 4(7)-acetamido-benzimidazole (91T7459). 

Dinitroquinoline derivative 94 under alkaline conditions condensed to give tri-azolo[4,5-c]quinoline oxide 95. On the other hand, heating 94 in aqueous acetic acid is reported to provide 50% yield of 96 (Scheme 15) (80M963). 

Den Hertog and Overhoff - observed that when pyridine in sulfuric acid is added to molten potassium sodium nitrate the 3-nitro derivative is formed at 300°C, whereas at 450°C 2-nitropyridme is the main product. The latter is probably a free-radical process. Schorigin and Toptschiew obtained 7-nitroquinoline by the action of nitrogen peroxide on quinoline at 100°C, possibly through the homolytic addition of NOa. Laville and Waters reported that during the decomposition of pernitrous acid in aqueous acetic acid, quinoline is nitrated in the 6- and 7-positions. They considered that the reaction proceeds as shown in Scheme 3. 

Hydrolysis of the amide 720 gave the acid 721. Boiling 721 in acetic acid for a prolonged period gave the dihydrofuro[3,4-6]quinoline 722 whose possible mechanism of formation is shown in Scheme 125 (85JCS(P1)1897). 

With acetic acid as solvent 68 is still the major product (Scheme 32). The minor product (69) probably forms in preference to the 3,5-isomer because the quinoline free base is reacting the high yield of 68 can be rationalized in terms of a 1,4- or 1,2-addition product that is rapidly bromi-nated at C-3. The 6- and 8-positions substitute more slowly [62JCS283, 62JCS291 77HC(32-1)319]. Both the 6- and the 8-bromoquinolines were 3-brominated under neutral conditions (62JOC1318). 

Bromine in acetic acid readily converted the activated 3-hydroxy-quinoline into its 4-bromo derivative (76%) under similar conditions 8-hydroxyquinoline gave a mixture of the 5-bromo and 5,7-dibromo compounds [71BAU400 72JOC4078]. All of the possible monobromo derivatives of the latter substrate have been made (91M935). 4-Hydroxy-... 

Quinoline yellow (E 104, Cl Food Yellow 13) is a quinophthalone dye consisting of a mixture of disulfonates (minimum 80%), monosulfonates (maximum 15%), and trisulfonates (maximum 7%) as sodium salts, obtained by the sulfonation of 2-(2-quinolyl)-l,3-indandione. The calcium and potassium salts are also permitted. Quinoline yellow is a yellow powder or granules, soluble in water, sparingly soluble in ethanol. The absorption maximum is at 411 nm in aqueous acetic acid solution, pH 5, = 865. It is not permitted as food colorant in the US. "... 

Grignon-Dubois and coworkers have shown that reduction of a quinoline using zinc and acetic acid in THF gives the dimeric compound 3-177 via intermediate 3-176 (Scheme 3.47) [70J. Usually, a mixture of the syn- and anti-products is formed the substituent has some influence on the regioselectivity of the dimerization and cydization step. With R = H and R = 6-Me, only the benzazepine 3-177 were produced, by a head-to-head dimerization. 

In general, symmetrical oxo-squaraines having the same end-groups are synthesized by reacting squaric acid with two equivalents of quatemized indolenine, 2-methyl-substituted benzothiazole, benzoselenazole, pyridine, quinoline [39, 45, 46] (Fig. 4) in a mixture of 1-butanol - toluene or 1-butanol - benzene with azeotropic removal of water in presence [39, 45] or absence [47] of quinoline as a catalyst. Other reported solvent systems include 1-butanol - pyridine [48], 1-propanol - chlorobenzene, or a mixture of acetic acid with pyridine and acetic anhydride [49]. Low CH-acidic, heterocyclic compounds such as quatemized aryl-azoles and benzoxazole do not react, and the corresponding oxo-squaraines cannot be obtained using this method [23, 50]. 

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