Novel 7-substituted quinolone antibacterial agents. Synthesis of 7-alkenyl,cycloalkenyl, and 1,2,3,6-tetrahydro-4-pyridinyl-1,8-naphthyridines

A convergent synthesis of 1,8-naphthyridine antibacterials bearing a carbon-carbon bonded, acyclic or cyclic vinyl substituent at the C-7 position has been achieved. The synthetic methodology is based upon the palladium-catalyzed cross coupling of a 7-chloro-1,8-naphthyridine with an appropriately substituted organotin reagent.     

An improved synthesis of 1-(1,2,3,6-tetrahydro-1-methyl-4-pyridinyl)ethanone,isoarecolone

A convenient synthesis of 1-(1,2,3,6-tetrahydro-1-methyl-4-pyridinyl)ethanone, isoarecolone, starting with 4-acetylpyridine is presented. 4-Acetylpyridine was protected as the ketal followed by reaction with iodomethane to give the quaterary salt. The quaterary salt was reduced with sodium borohydride followed by deprotection to give isoarecolone in 80% overall yield.     

Synthesis and Crystal Structure of Rctt-1-(2-benzoxazolyl)-2-(4-chlorophenyl)-4-phenyl-3-(4-pyridinyl)cyclobutane

1INTRODUCTIONThephotodimerizationof1,2-bisarylethenederivativesisaconvenientwayforsynthesizingtetraarylsubstitutedcyclobutane.Forthisreason,thephotochemistryofstilbeneandstyrylpyridinederivativeshasbeenextensivelystudied[1,2].UpontheirradiationwithUVlight(?=300～400nm),thesemonomersareconvertedtohead-to-tailphotodimersinpolarsolventwithperfectyields.Inrecentyears,ourgrouphasbeenstudyingthephotodimerizationreactionsofheteroarylethenescontainingbenzoxazolyl[3]andphenyloxazolyl[4]groups.Itw…     

Synthesis of 2- and 3-pyridinyl(aryl)methanones

A procedure was developed for the preparation of 2- and 3-pyridinyl(aryl)methanones by the reactions of aryllithium with methyl pyridinecarboxylate and methyl esters of substituted phenylcarboxylic acids.     

Synthesis of 7-ethyl-4,7-dihydro-4-oxo-2-(4-pyridinyl)thieno[2,3-b]pyridine-5-carboxylic acid

7-Ethyl-4,7-dihydro-4-oxo-2-(4-pyridinyl)thieno[2,3-b]pyridine-5-carboxylic acid ( 4 ), an analog of nalidixic acid, was synthesized in seven steps starting from commercially available 4-methylpyridine. Bacterial susceptibility to compound 4 was tested and the title compound was found to exhibit only weak antibacterial activity against a variety of pathogens including S. Aureus, E. Coli and P. Aeruginosa.     

A convenient synthesis of 3-(4-pyridinyl)quinolines

3-(Arylamino)-2-(4-pyriclinyl)acroleins 3 prepared by reacting anilines 1 with 3-(dimethylamino)-2-(4-pyridinyl)acrolein ( 2 ) were cyclized with phosphorus oxychloride or acetic acid to give 3-(4-pyridinyl)quinolines 4 .     

Synthesis and spectral properties of n-alkyl-4-methyl-7(8)-nitro-2,3,4,5-tetrahydro-(1h)-1,5-benzodiazepin-2-ones

Alkylation of 4-methyl-7(8)-nitro-2,3,4,5-tetrahydrobenzodiazepin-2-ones under phase transfer catalytic conditions or in dry acetone occurs only at position 1. The 5-alkyl isomers are obtained by reductive alkylation of 4-methyl-7(8)-nitro-2,3-dihydro-1,5-benzodiazepin-2-ones. The UV, IR, PMR, and mass spectra of the isomeric compounds are reported.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 959–963, July, 1992.     

Synthesis of N,N-Bis(4-pyridinyl)piperazine (Bis-DMAP) as Novel Supernucleophilic Reagent

In the late 1960's,4-(N,N-dimethylamino)pyridine (1,DMAP) and 4-pyrrolidinopyridine (2, PPY) as high efficient supernucleophilic catlyst the benzoylation of m-chloroaniline were found independently by two research groups.^[1,2]     

高分子(纤维)负载-N-(4-吡啶)哌嗪的合成及其催化性能

以废旧聚丙烯纤维为骨架,通过接枝苯乙烯、氯甲基化和负载N-(4-吡啶)哌嗪,合成了高分子(纤维)负载-N-(4-吡啶)哌嗪(1),其结构经IR和元素分析表征,并通过小分子模拟确证.1(5 mol%)用于催化1-苯基乙醇的乙酰化反应,收率90%,在多次循环使用后催化活性基本不变.     

Synthesis and Fungicidal Activity of Substituted N-(Alkoxy)-1-(3-pyridinyl)methanonimines

Russian Journal of General Chemistry - A number of new substituted N-(alkoxy)-1-phenyl- and N-(alkoxy)-1-cyclohexyl-1-(3-pyridinyl)-methanonymines were prepared by reacting the corresponding...     

Synthesis of 1-(3',4'-dihydroxyphenyl)-7-(4"-hydroxyphenyl)- 4hepten-3-one

Natural diarylheptanoids have significant bioactivities. Some of them are potent inhibitors against prostaglandin biosynthesizing enzyme (PG synthetase) and 5-lipoxygenase (LT synthetase)1-2. Compound 1 was firstly isolated from Alnus rubra bark3. So far its synthesis has not been reported yet. Herein, we report the synthesis of compound 1. Meantime, compound 24 was also obtianed as an intermediate. Compound 7 and 16 were converted to compound 10 and 18 respectively, because compound 1…     

Quinolone antibacterials. 1. 7-(2-substituted-4-thiazolyl and thiazolidinyl)quinolones

A series of 7-(2-substituted-4-thiazolyl and thiazolidinyl)-1-ethyl-1,4-dihydro-4-oxoquinoline-3-carboxylic acids and their 6-fluoro analogues were synthesized. The Hantzsch method was used for the preparation of the thiazolylquinolones. The thiazolidinylquinolones were synthesized by quaternization of the corresponding thiazolyl analogues, followed by reduction of the obtained thiazolium salts with sodium borohydride in aqueous solution. Antibacterial activity was tested in vitro. Most of the compounds were inactive against Gram-negative bacteria but some of them showed however good activity against Gram-positive bacteria and mycobacteria. This activity pattern is rarely found among the quinolone antibacterials.     

Synthesis of 4-phenyl-1-(2-thienyl)-2,3,4,9-tetrahydro-1H-β-carboline

The Pictet-Spengler reaction involving β-phenyltryptamine was shown to be diastereo-specific with formation primarily of the (1S*,4R*) diastereomer of 4-phenyl-1-(2-thienyl)-2,3,4,9-tetrahydro-1H-β-carboline, a compound with potential GABA-receptor activity. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 468–470, September–October, 2006.     

Conversion of 1-alkoxy (aryloxy)-5-methyl-1,2,3,6-tetrahydro-1,2,6-phosphadiazine-1,3-diones to 4-hydroxy-6-methylpyrimidine

Chemistry of Heterocyclic Compounds -     

Synthesis of New Heterocyclic Systems on the Basis of 7-Benzyl-3-chloro-1-(morpholin-4-yl)-5,6,7,8-tetrahydro-2,7-naphthiridine-4-carbonitrile

Methods have been developed for the synthesis of new 8-amino-3-benzyl-5-(morpholin-4-yl)-1,2,3,4-tetrahydropyrimido[4′,5′: 4,5]thieno[2,3-c][2,7]naphthyridine starting from 7-benzyl-3-chloro-1-(morpholin-4-yl)-5,6,7,8-tetrahydro-2,7-naphthyridine-4-carbonitrile. 8-Hydrazinyl-3-benzyl-5-(morpholin-4-yl)-1,2,3,4-tetrahydropyrimido[4′,5′: 4,5]thieno[2,3-c][2,7]naphthyridine has been converted to isomeric pentacyclic structures with a triazole ring fused through the [c] side of the pyrimidine ring, and their Dimroth rearrangement has been accomplished in both acidic and basic media. New heterocyclic systems containing pyrrolo[1,2-a]pyrimidinone and pyrimido[1,2-a]azepinone fragments were obtained on the basis of the thieno-[2,3-c][2,7]naphthyridine derivative.