Syntheses of Benzoxepinoquinolinone and Benzothiepinoquinolinone

l-Benzoxepino(3, 4-b)quinolin-l3(6H)-one and its halogen,alkyl, alkoxy derivatives Va'-d' and 1-benzothiepino(3,4-b}-quinolin- 13 ( 6H)-one Vf, and its alkyl derivatives Vg, weresynthesized through cyclization of 2-(substituted phenoxymethyl)-3-quinolinecarboxylic acids Va-d and 2-[ (un)substituted phen-ylthiomethyll-3-quinolinecarboxylic acids IVf-g in the presence ofpolyphosphoric acid.The acids IV were obtained from the corresponding ethyl-esters @ whcih were prepared through refluxing ethyl 2-bromo-methyl-3-quinolinecarboxylate(1) with substituted phenol or (un)substituted thiophenol in the presence of NaOEt.The compound Vg, was allowed to react with NBS, KaBH4, NH2OH-HCl to give compounds VII , VIII, and IX, respectively.The structures of 24 new compounds have been confirmed by elemental analysis, IR and 1H NMR.     

Synthesis of 5-methyl-4-oxo-quinolinecarboxylic acids

A series of 5-methyl-4-oxo-3-quinolinecarboxylic acids was prepared in which the eight-position was substituted with fluorine, chlorine, methyl, or hydrogen. These quinolones were synthesized from the appropriate 2-methyl-3,4,6-trifluorobenzoic acids which were derived from oxazolines 8 and 16 . The oxazoline moiety served as both an ortho-director (where feasible) and a protecting group; a trimethylsilyl moiety was used to block the most acidic site in the molecule.     

Synthesis and isomeric conversions of several 2-substituted 1,4-dihydro-4-oxo-3-quinolinecarboxylic acid derivatives

Ethyl ester derivatives of 6- and 8-substituted 2-methyl-1,4-dihydro-4-oxo-3-quinolinecarboxylic acids have been synthesized by treatment of the diethyl ester of acetylmalonic acid with 2- or 4-substituted anilines. Condensation of these newly synthesized quinolinecarboxylic acid derivatives with 4-nitrobenzaldehyde resulted in the formation of 6- and 8-substituted 2-[2-(4-nitrophenyl)-vinyl]-1, 4-dihydro-4-oxo-3-quinolinecarboxylic acids and ethyl esters of 6- and 8-substituted 2-[2-(4-nitrophenyl)vinyl]-4-acetoxy-3-quinolinecarboxylic acids. The tautomeric and conformational transformations of these newly synthesized compounds have also been investigated, using IR, NMR, and UV spectroscopy.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 931–938, July, 1988.     

Studies on quinoline derivatives and related compounds. II. Synthesis of 5-substituted 1-ethyl-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid

The cyclization of m-substituted anilinomethylenemalonates ( 1 ) in the presence of polyphosphate ester and some other cyclizing agents gave mixtures of the isomeric ethyl 5- ( 2 ) and 7-substituted 4-hydroxy-3-quinolinecarboxylates ( 3 ), which led to mixtures of the corresponding quinolinecarboxylic acids ( 4 and 5 ) by hydrolysis. The proportions of 4 and 5 in the mixtures were determined on the basis of their nmr spectra. Novel 5-chloro- ( 8a ), 5-methyl- ( 8b ) and 5-nitro-1-ethyl-1,4-dihydro-4-oxo-3-quinolinecarboxylic acids were prepared and evaluated for antimicrobial activities. No significant activity, however, was noted.     

New 7-substituted quinolone antibacterial agents. The synthesis of 1-ethyl-1,4-dihydro-4-oxo-7-(2-thiazolyl and 4-thiazolyl)-3-quinolinecarboxylic acids

A series of 1-ethyl-1,4-dihydro-4-oxo-7-(4-thiazolyl)-3-quinolinecarboxylic acids and 1-ethyl-1,4-dihydro-4-oxo-7-(2-thiazolyl)-3-quinolinecarboxylic acids were prepared. Also prepared was 10-[2-(aminomethyl)-4-thiazolyl]-9-fluoro-2,3-dihydro-3-methyl-7-oxo-7H-pyrido[1,2,3-de][1,4]benzoxazine-6-carboxylic acid. Analogs with basic amine substituents on the thiazole moiety were found to have antibacterial activity.     

Reduction of quinolinecarboxylic acids by raney alloy

The heterocyclic nucleus in quinolinecarboxylic acids is reduced by Raney alloy (nickel-aluminium) in alkaline media to give 1,2,3,4-tetrahydro-2-,3-,4-,5-,6-, and 8-quinolinecarboxylic acids and 8-methyl-5-quinolinecarboxylic acid and their ethyl esters.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 77–79 January, 1988.     

Reactions of N-hydroxysuccinimide esters of anthranilic acids with anions of beta-keto esters. A new route to 4-oxo-3-quinolinecarboxylic acid derivatives

A new approach for the synthesis of 4-oxo-3-quinolinecarboxylic acid derivatives is described. This methodology involves the C-acylation of the anions of appropriate beta-keto esters with novel N-hydroxysuccinimide esters of anthranilic acids. The intermediate C-acylation products 3 are spontaneously cyclized to afford 3-ethoxycarbonyl-4-oxoquinoline derivatives 4. The introduction of a variety of substituents at positions 1 and 2 of the quinoline ring is feasible with the selection of suitable anthranilic acids and beta-keto esters. The structure of the obtained 2-substituted 3-ethoxycarbonyl-4-oxoquinolines was confirmed by IR and NMR spectral data.     

Studies on quinoline derivatives and related compounds. VI. A novel displacement reaction of 1-ethylquinolinium iodides with nucleophiles

The reaction of 4-amino- ( 3a ) and 4-anilino-3-carbethoxy-1-ethyl-6,7-methylenedioxy-quinolinium iodide ( 3b ) with nucleophilic reagents produced 7-substituted 4-amino-3-carboxy-1-ethyl-6-hydroxyquinolinium betaines ( 5b-d ) and 7-substituted 1-ethyl-1,4-dihydro-6-hydroxy-4-phenylimino-3-quinolinecarboxylic acid ( 6b-d ), respectively, which led to 7-substituted 1-ethyl-1,4-dihydro-6-hydroxy-4-oxo-3-quinolinecarboxylic acids ( 1b-d ) by alkaline hydrolysis. With a variety of 1-ethyl-1,4-dihydroquinoline carboxylates ( 16a-e ) these novel displacement reactions were attempted.     

1-Ethyl-1,4-dihydro-4-oxo-7-(pyridinyl)-3-quinolinecarboxylic acids. I. Synthesis of 3- and 4-(3-aminophenyl)pyridine intermediates

A series of substituted 3- and 4-(3-aminophenyl)pyridines has been prepared as intermediates for the synthesis of some 1-alkyl-1,4-dihydro-4-oxo-7-pyridinyl-3-quinolinecarboxylic acids. The Hantzsch, Hauser and other pyridine syntheses were used. 4-(3-Aminophenyl)pyridine was prepared via 3-(4-pyridinyl)-2-cyclohexen-1-one using the Semmler-Wolff reaction.     

Synthesis and selected transformations of 1-(5-methyl-1-aryl-1H-1,2,3-triazol-4-yl)ethanones and 1-[4-(4-R-5-methyl-1H-1,2,3-triazol-1-yl)phenyl]ethanones

By cycloaddition of arylazides to acetylacetone are obtained derivatives of 1,2,3-triazole. In the reaction of 1-[5-methyl-1-(R-phenyl)-1H-1,2,3-triazol-4-yl] ethanones (IIa–IIe) and 1-[4-(4-R-5-methyl-1H-1,2,3-triazol-1-yl)phenyl] ethanones (VIIa-VIIe) with isatin are obtained 2-[1-(R-phenyl)-5-methyl-1H-1,2,3-triazol-4-yl]-4-quinolinecarboxylic acids (IIIa–IIIe) and 2-[4-(4-R-5-methyl-1H-1,2,3-triazol-1-yl)phenyl] -4-quinolinecarboxylic acids (IXa, IXb), respectively. We found that 1-[5-methyl-1-(R-phenyl)-1H-1,2,3-triazol-4-yl] ethanones (IIa–IIe) readily transform into [5-methyl-1-(R-phenyl)-1H-1,2,3-triazol-4-yl] acetic acids (IVa–IVc) by the method of Wilgerodt-Kindler. The (5-methyl-1-phenyl-1H-1,2,3-triazol-4-yl)acetic acid reacts with 5-phenyl-4-amino-4H-1,2,4-triazol-3-thiol affording 6-[(5-methyl-1-phenyl-1H-1,2,3-triazol-4-yl) methyl]-3-phenyl[1,2,4] triazolo[3,4-b] [1,3,4] thiadiazole (VI). Original Russian Text ? N.T. Pokhodylo, R.D. Savka, V.S. Matiichuk, N.D. Obushak, 2009, published in Zhurnal Obshchei Khimii, 2009, vol. 79, no. 2, pp. 320–325.     

Studies on quinoline derivatives and related compounds. 1. A new synthesis of 1-alkyl-1,4-dihydro-4-oxo-3-quinolinecarboxylic acids

A novel preparative method for 1-alkyl-1,4-dihydro-4-oxo-3-quinolinecarboxylic acids was developed. The key process is the cyclization of N-alkylanilinomethylenemalonales, which was effected successfully in the presence of polyphosphoric acid, polyphosphate ester, boron tri-fluoride or a mixture of acetic anhydride and sulfuric acid. With phosphorus oxychloride, N-alkylanilinomethylenemalonates yielded 1-alkyl-4-chloro-3-carbethoxyquinolinium salts which were hydrolyzed readily to ethyl 1-alkyl-1,4-dihydro-4-oxo-3-quinolineearboxylates or their acids. By means of this novel method several new 1-alkyl-1,4-dihydro-4-oxo-3-quinolineearboxylic acids were prepared.     

Synthesis and reaction of 5-amino-3-trifluoromethylisoxazole and -pyrazole-4-carboxylic acids

5-Amino-3-trifluoromethylisoxazole- and -pyrazole-4-carboxylic acids were prepared by the reactions ot trifluoroacetonitrile oxide or -imines with cyanoacetic acid derivatives, respectively. The behavior of thus obtained aminoazole-4-carboxylic acids toward some electrophiles was examined. In acylation with acyl chlorides, the aminoisoxazole-4-carboxylate 2a was diacylated to give the (diacylamino)isoxazole-4-carboxylate 7 , whereas the analogous aminopyrazole 5a produced the cyclized pyrazolooxazinone 13 . Moreover, carbamoylation of 2a with isocyanates gave the trifluoromethylisoxazolouracils 10 .     

The synthesis of 3-bromo-2,4,5-trifluorobenzoic acid and its conversion to 8-bromoquinolonecarboxylic acids

A series of 8-bromo-4-oxo-3-quinolinecarboxylic acids was prepared via the borate ester, 8 . The key intermediate in the synthesis of the final products 10a-10d was 3-bromo-2,4,5-trifluorobenzoic acid ( 3 ), conveniently prepared in two steps from the known oxazoline, 1 . The preparation of 10a-10d is a significant improvement of the literature procedure currently available for the synthesis of these compounds.     

Synthesis of heterocycles on the basis of arylation products of unsaturated compounds. 19.* Arylation of 2-acetylthio- phene and the synthesis of 2-(5-aryl-2-thien- yl)-4-quinolinecarboxylic acids

The reaction of 2-acetylthiophene with acetylthiophene with arenediazonium chlorides in the presence of cupric chloride as catalyst gives 2-acetyl-5-arylthiophenes. These products react with 5-chloro- and 5-bromoisatins to give 6-chloro- and 6-bromo-substituted 2-(5-aryl-2-thienyl)-4-quinolinecarboxylic acids.     

4-Hydroxy-2-quinolones. 90. Synthesis and antitubercular activity of 4-methyl-2-thiazolylamides of halo-substituted 4-hydroxy-2-oxo-1,2-dihydro-3-quinolinecarboxylic acids

Several variants were studied for the synthesis of esters of halogen derivatives of 4-hydroxy-2-oxo-1,2-dihydro-3-quinolinecarboxylic acids, whose reaction with 2-amino-4-methylthiazole gives the corresponding hetarylamides. Results are given for a study of the antitubercular activity of these products. Communication 89, see ref. [1]. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 71–76, January, 2006.     

2-Methylisoxazolin-5-ones III. Curboxylic. Acids and their Derivatives

Carbethoxy-substituted 12-methylisoxazolin-5-ones and several functional derivatives have been prepared. Spectral properties of the corresponding carboxylic acids are discussed. These acids ant stronger when the carboxy group is in position 3 than when in position 4 of the heterocycle.     

Studies on chemotherapeutics I. Synthesis of 5-substituted-4-oxo-1,4-dihydro-3-pyridinecarboxylic acid derivatives

Ethyl 5-substituted-4-oxo-1,4-dihydro-3-pyridinecarboxylates were synthetized by reacting 1,3,5-triazine with 4-substituted ethyl acetoacetate derivatives in ethanol, in the presence of sodium ethoxide. The l-alkyl-5-substituted-4-oxo-1,4-dihydro-3-pyridinecarboxylic acids required for the antimicrobial studies were prepared by N-alkylation (with triethyl phosphate or alkyl halides) and alkaline hydrolysis of the pyridone esters.     

Synthesis and transformations of polysubstituted diastereomeric 5-oxomorpholin-2-carboxylic acids

A series of trans- and cis-3,4-disubstituted 5-oxomorpholine-2-carboxylic acids 5 were prepared by a cyclocondensation between diglycolic anhydride 3 and arylideneamines 4. Transformations of the carboxylic group leading to a peptide bond in the side chain to the morpholinone ring were effected. The relative configurations and the preferred conformations of the substituents at the morpholinone ring in some of the newly prepared derivatives were determined by means of ¹H NMR and X-ray analysis.     

Synthesis,structure elucidation and chemotherapeutic activity of 6-substituted 1-ethyl-1,4-dihydro-7-[(1-imidazolyl)phenylmethyl]- 4-oxo-3-quinolinecarboxylic acids

The synthesis, structure elucidation and chemotherapeutic activity of novel 3-quinolinecarboxylic acid derivatives are reported. These derivatives are characterized by a group (1-imidazolyl)phenylmethyl attached to the 7-position and chloro 10a , fluoro 10b or methoxy 10c appended to the 6-position.     

Stereoselective synthesis of the 5'-hydroxy-5'-phosphonate derivatives of cytidine and cytosine arabinoside

Both the (R)- and (S)-5'-hydroxy 5'-phosphonate derivatives of cytidine and cytosine arabinoside (ara-C) have been prepared via phosphite addition or a Lewis acid mediated hydrophosphonylation of appropriately protected 5'-nucleoside aldehydes. Phosphite addition to a cytosine aldehyde protected as the 2',3'-acetonide gave predominately the 5'R isomer, while phosphite addition to the corresponding 2',3'-bis TBS derivative favored the 5'S stereochemistry. In contrast, phosphite addition to the 2',3'-bis TBS protected aldehyde derived from ara-C gave only the 5'R adduct. However, TiCl(4)-mediated hydrophosphonylation of the same ara-C aldehyde favored the 5'S stereoisomer by a 2:1 ratio. Once all four of the diastereomers were in hand, the stereochemistry of these compounds could be assigned based on their spectral data or that obtained from their O-methyl mandelate derivatives. After hydrolysis of the phosphonate esters and various protecting groups, the four alpha-hydroxy phosphonic acids were tested for their ability to serve as substrates for the enzyme nucleoside monophosphate kinase and for their toxicity to K562 cells.