- Microwave-assisted synthesis of quinolone derivatives and related compounds
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(Chemical Equation Presented) The Gould-Jacob type of reaction for the synthesis of ethyl 5-ethyl-8-oxo-5,8-dihydro-[1,3]-dioxolo[ 4,5-g]quinoline-7- carboxylate 4 has been carried out conventionally by the condensation between N-ethyl-3,4-methylenedioxyaniline 1 and diethyl ethoxymethylenemalonate 2 gave the unsaturated ester 3 and thermal cyclization in refluxing diphenyl oxide gave quinolone ethyl ester 4 and the results obtained were compared with single step microwave irradiation under solvent free conditions for the synthesis of 4. The esters on basic hydrolysis formed free acid 5, which, upon treatment with thionyl chloride gave the acid chloride 6. Treatment of acid chloride with o-phenylenediamine, hydrazine hydrate, ammonia, urea, and thiourea gave the amides (7-11). CS2 treatment in presence of KOH on 8 gave 12. We prepared 7-12 derivatives by conventional as well as microwave irradiation. These compounds have been characterized on the basis of IR, 1H NMR, MS, and elemental analysis. All the compounds prepared herein were screened for their antibacterial activity. Compounds 4, 5 possess promising antibacterial activity and compound 8 showed significant antibacterial activity.
- Pednekar, Suhas,Pandey, Anil Kumar
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- Copper-Catalyzed Synthesis of Substituted 4-Quinolones using Water as a Benign Reaction Media: Application for the Construction of Oxolinic Acid and BQCA
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A copper-catalyzed three-component synthetic method has been developed for the synthesis of substituted 4-quinolone derivatives from substituted 3-(2-halophenyl)-3-oxopropane, aldehydes and aq. NH3 using water as an environmentally benign reaction media. Moreover, the synthetic utility of the obtained products has been successfully applied for the synthesis of available oxolinic acid and BQCA drugs. The key features of this approach include commercially available starting materials, broad scope, and moderate to good reaction yields. Reaction with formaldehyde, and other functionalities such as ?CN, ?NO2, ?SO2Ar, and ?COAr were also successful. In addition, reaction with heterocyclic compounds such as 3-(3-bromothiophen-2-yl)-3-oxopropanenitrile proceeded smoothly to afford tetrahydrothieno[3,2-b]pyridine-6-carbonitrile analogues. The practicality of the designed protocol was confirmed by gram scale synthesis of two derivatives. (Figure presented.).
- Gore, Babasaheb Sopan,Lee, Chein Chung,Lee, Jessica,Wang, Jeh-Jeng
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- Synthetic method of oxolinic acid
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The invention relates to a synthetic method of oxolinic acid, and belongs to the technical field of chemical synthesis. The synthetic method provided by the invention includes the following steps: (1)reacting a compound I with a compound II at 120-150 DEG C to obtain a compound III; (2) cooling a mixed solution obtained in the step (1) to 70-110 DEG C, adding acetic anhydride and concentrated sulfuric acid in order, and heating to 120-140 DEG C for reaction; and (3) after the reaction in the step (2) is finished, lowering the temperature to 80-95 DEG C, and adding water for a hydrolysis reaction to obtain the oxolinic acid. The method of the invention is high in yield, greatly reduced in production cost and good in product quality, and is suitable for industrial production. The concrete synthetic route is shown in the description.
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Paragraph 0025-0028
(2019/05/08)
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- Rhodium-catalyzed ortho C-H bond activation of arylamines for the synthesis of quinoline carboxylates
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The rhodium catalyzed annulation of anilines with alkynic esters allowing for the high-yield synthesis of quinoline carboxylates with excellent regioselectivity is described. This unprecedented reaction employs either formic acid as the C1 source and reductant or copper(ii) as the oxidant and is proposed to proceed via rhodacycle of in situ generated amide and enamine ester followed by ortho C-H activation of arylamines with rhodium as the catalyst.
- Gadakh, Sunita K.,Dey, Soumen,Sudalai
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p. 2969 - 2977
(2016/03/12)
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- A ONE POT SYNTHESIS OF 3-SUBSTITUTED QUINOLINE CARBOXYLATES AND ITS DERIVATIVES
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The present invention provides a one pot, simple, cost effective and industrially feasible catalytic synthesis of quinolines or substituted quinolines from anilines with yield >80% yield. The present invention also discloses a process for the synthesis of oxolinic acid using quinolines with yield > 45%.
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Page/Page column 19
(2016/01/25)
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- Synthesis of 5-ethyl-8-oxo-5.8-dihydro-1,3-dioxolo [4,5-g] quinolines and related compounds
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Condensation of N-ethyl-3,4-methylenedioxyaniline 1 with diethyl ethoxymethylenemalonate 2 gave the unsaturated ester 3 which on thermal cyclization in refluxing diphenyl oxide gave ester 4. The ester on basic hydrolysis formed free acid 5 which upon treatment with thionyl chloride gave the acid chloride 6. Treatment of 6 with o-phenylenediamine, hydrazine hydrate, ammonia, urea and thiourea gave the amides (7-11). CS2 treatment in presence of KOH on 8 gave 12. 7-12 were prepared by conventional as well as under microwave irradiation. These compounds have been characterized on the basis of elemental analysis, IR, NMR and MS data.
- Pednekar, Suhas,Pandey, Anil Kumar
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p. 357 - 360
(2011/12/16)
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- A process for the preparation of N-alkyl-3,4-dialkyloxyanilines and derivatives thereof
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The invention provides a process for the preparation of N-alkyl-3,4-dialkyloxyanilines and derivatives thereof of the formula I wherein R1 and R2 are each identical or different lower alkyl groups or R1 and R2 taken together form a methylene bridge and R3 is H or lower alkyl comprising bromination of a compound of formula II wherein R1 and R2 are as defined above to form a compound of formula III and then reacting said compound with an aqueous alkyl amine or ammonia of the formula R3NH2 wherein R3 is as defined above to effect amination of the bromo amination of the bromo intermediate of formula III to form the compounds of formula I.
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- 3-Imino-1,2,4-benzotriazine-1-oxides
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New 3-Imino-1,2,4-benzotriazine-1-oxides of formula I SPC1 wherein R represents an alkyl, alkenyl or haloalkyl radical, a phenyl or aralkyl radical optionally substituted by alkyl, alkoxy, haloalkyl, halogen or hydroxy, X and Y each independently represent hydrogen, halogen, an alkyl or alkoxy radical, or one of the two symbols represents a phenoxy or phenylsulphonyl radical optionally substituted by halogen, alkyl, haloalkyl and/or alkoxy which are active against harmful microorganisms are disclosed.
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