Studies on uricosuric diuretics. II. Substituted 7,8-dihydrofuro[2,3-g]-1,2-benzisoxazole-7-carboxylic acids and 7,8-dihydrofuro[2,3-g]benzoxazole-7-carboxylic acids.

A series of substituted 7,8-dihydrofuro[2,3-g]-1,2-benzisoxazole-7-carboxylic acids 9 and 7,8-dihydrofuro[2,3-g]benzoxazole-7-carboxylic acids 12 were synthesized and evaluated for uricosuric and diuretic activities in rats. Many of the benzisoxazole derivatives 9 showed uricosuric and only weak diuretic activities, whereas the benzoxazoles 12 exhibited potent diuretic activities with little affecting urate excretion. Among these compounds, 5-chloro-7,8-dihydro-3-phenylfuro[2,3-g]-1,2-benzisoxazole-7-carbo xylic acid (9b, AA-193) was found to be a potent uricosuric agent without diuretic activity and was selected for further development.     

Aryloxyacetic acid diuretics with uricosuric activity. II. Substituted [(4-oxo-4H-1-benzopyran-7-yl)oxy]acetic acids and the related compounds.

Di- and tri-substituted [(4-oxo-4H-1-benzopyran-7-yl)oxy]acetic acids, and 4-oxo-3-phenyl-4H-furo[2,3-h]-[1]benzopyran-8-carboxylic acid were synthesized and tested for natriuretic and uricosuric activities. Among the compounds tested, 3,5-disubstituted [(4-oxo-4H-1-benzopyran-7-yl)oxy]acetic acids (6c-f, h, n and x) showed potent natriuretic and uricosuric activities, whereas 4-oxo-3-phenyl-4H-furo[2,3-h][1]benzopyran-8-carboxylic acid (6dd) possessed only potent natriuretic activity. The structure-activity relationships are also discussed.     

Studies on uricosuric diuretics. III. Substituted 1,3-dioxolo[4,5-f]-1,2-benzisoxazole-6-carboxylic acids and 1,3-dioxolo[4,5-g]-1,2-benzisoxazole-7-carboxylic acids.

A series of substituted 1,3-dioxolo[4,5-f]-1,2-benzisoxazole-6-carboxylic acids 13 and 1,3-dioxolo[4,5-g]-1,2-benzisoxazole-7-carboxylic acids 14 were synthesized and evaluated for diuretic and uricosuric activities in rats. Most of the benzisoxazole derivatives 13 and 14 showed potent diuretic activities. Moderate uricosuric activities were also found in 14a, 14b, and 14f.     

Facile synthesis of some novel pyrido[3',2':4,5]thieno[2,3-b][1,4]thiazine-8-carboxylic acids

Model tetrahydropyrido[3',2':4,5]thieno[2,3-b][1,4]thiazines 9a-c were synthesized via reductive lactamization, using sodium dithionite, of the respective 2-[(carboxyalkyl)thio]-3-nitro-4,7-dihydrothieno[2,3-b]pyridine-5-carboxylic acids 7a-c. The latter derivatives were made via interaction of 2-chloro-7-cyclopropyl-3-nitro-4,7-dihydrothieno[2,3-b]pyridine-5-carboxylic acid (6) with each of alpha-mercaptoacetic, alpha-mercaptopropionic, and alpha-mercaptosuccinic acids and triethylamine in aqueous acetone at room temperature. The structures of 7a-7c and 9a-9c are supported by microanalytical and spectral (IR, MS, NMR) data. Compounds 9a and 9c showed potent inhibitory activity against the IGROV1 (Ovarian Cancer) cell line.     

Synthesis of condensed structures from 3-cyano-2-pyridylacrylic acids

Ammonolysis of the methyl esters of trans--(3-cyano-2-pyridyl)acrylic (I) and trans--(6-methyl-3-cyano-2-pyridyl)acrylic (II) acids gave the amides of these acids. The addition of bromine, diazomethane, and hydrogen to the double bond of cis- and trans-acids I and II is described. Hydrogenation of the methyl esters of trans-acids I and II over Raneynickel at room temperature and atmospheric pressure occurs with intramolecular cyclization to two-ring lactams — 7-oxo-5, 6,8,9-tetrahydropyrid[3,2-c]azepine and 2-methyl-7-oxo-5,6,8,9-tetrahydropyrid[3,2-c]azepine. Under the conditons of acid hydrolysis of acids I and II the elements of water add to the nitrile group with intramolecular cyclization to give, respectively, 3-carboxymethyl-1-oxo-2,3-dihydrofuro [4,3-b]pyridine and 5-methyl-3-carboxymethyl-1-oxo-2,3-dihydrofuro[4,3-b]pyridine, whereas refluxing these acids with aqueous sodium hydroxide gives two-ring lactams — 3-carboxymethyl-1-oxo-2, 3-dihydropyrrolo[4,3-b]pyridine and its 5-methyl homolog. The structures of the compounds were confirmed by the UV, IR, PMR, and mass spectra.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 63–69, January, 1978.     

Studies on antibacterial agents. II. Synthesis and antibacterial activities of substituted 1,2-dihydro-6-oxo-6H-pyrrolo[3,2,1-ij]quinoline-5-carboxylic acids

A series of substituted 1,2-dihydro-6-oxo-pyrrolo[3,2,1-ij]quinoline-5-carboxylic acids for the treatment of systemic infections was synthesized via 7-bromo-3-ethylthio-4,5-difluoro-2-methylindole (3), which was prepared by Gassman's indole synthesis in excellent yield. The synthesized pyrroloquinolines were tested for their antibacterial activities. 8-Fluoro-1,2-dihydro-2-methyl-9-(4-methyl-1-piperazinyl)-6-oxo-6H- pyrrolo[3,2,1-ij]quinoline-5-carboxylic acid showed a potent antibacterial activity against gram-positive and gram-negative bacteria.     

Fluorinated pyrido[2,3-c]pyridazines. II. Synthesis and antibacterial activity of 1,7-disubstituted 6-fluoro-4(1H)-oxopyrido[2,3-c]pyridazine-3- carboxylic acids

Chemical modification of pyridonecarboxylic acid antibacterials with a 1,8-naphthyridine ring, such as enoxacin and tosufloxacin, to their 2-aza derivatives was studied. A new series of 1,7-disubstituted 6-fluoro-4(1H)-oxopyrido[2,3-c]pridazine-3-carboxylic acids (25-27) was prepared by a route involving either alkylation of ethyl 6-fluoro-4(1H)-oxo-7-(p-tolylthio)pyrido[2,3-c]pyridazine-3-carbox ylate (7) or intramolecular cyclization of ethyl 2-(2,6-dichloro-5-fluoronicotinoyl)-2-[2-(p-fluorophenyl)hydraz ono]acetate, (20), followed by displacement reaction with cyclic amines at C-7; the N-1 substituent in these compounds included of ethyl, 2-fluoroethyl and p-fluorophenyl groups, and the C-7 functional group comprised variously-substituted piperazines and pyrrolidines. Antibacterial activities of these compounds were markedly inferior to those of enoxacin and tosufloxacin.     

Synthesis of polyheterocyclic compounds derived from 6-amino- 4-aryl-2-r-4h-furo[2,3-<Emphasis Type="Italic">b</Emphasis>]pyran-5-carbonitriles

Syntheses were developed for 4-aryl-6-ethoxy-2-R-furo[2,3-b]pyridine-5-carbonitriles and ethyl esters of 5-amino-4-aryl-7-methyl-2-R-1,9-dioxa-8-azacyclopenta[b]naphthalene-6-carboxylic acids based on the reaction of 6-amino-4-aryl-2-R-4H-furo[2,3-b]pyran-5-carbonitriles with ethyl acetoacetate and nucleophilic recyclization. The mechanisms of these reactions are considered.     

Synthesis of methyl esters of 5-amino-4-(substituted amino)-2-methylthio-7H-pyrrolo[2,3d]-pyrimidine-6-carboxylic acids

The optimum route for the synthesis of methyl esters of N-[(4-substituted amino)-5-cyano-2-methylthiopyrimidin-6-yl]amino acids (which are starting materials for preparing the methyl esters of the corresponding 5-amino-4-(substituted amino)pyrrolo[2,3-d]pyrimidine-6-carboxylic acids) is via subsequent reactions of 4,6-dichloro-2-methylthiopyrimidine-5-carbonitrile with amines and methyl glycinate. In some examples, the reaction of methyl N-(4-chloro-2-methylthio-6-pyrimidinyl)aminoacetate with amines occurs to give the corresponding acid amides. The previously unknown synthesized derivatives of pyrimidin-6-yl amino acids and 4,5-diaminopyrrolo[2,3-d]pyrimidine- 6-carboxylic acids possess fungicidal properties.Vilnius University, Vilnius 2006, Lithuania. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No 7, pp. 955–961, July, 2000.     

Synthesis of 6′-carbamoylmethylthio-5′-cyano-1′,4′-dihydro-3,4′-bipyridine-3′-carboxylic and 6′-carbamoylmethylthio-5′-cyano-1′,4′-dihydro-4,4′-bipyridine-3′-carboxylic esters and investigation of their stability. 2. Esters of 6′-carbamoylmethyl-thio-5′-cyano-1′,4′-dihydro-4,4′-bipyridine-3-carboxylic acids

The stability of solutions of esters of 6′-carbamoylmethylthio-5′-cyano-2′-methyl-1′,4′-dihydro-4,4′-bipyridine-3′-carboxylic acids was investigated by HPLC. The corresponding esters of 6′-carbamoylmethylthio-5′-cyano-4,4′-bipyridine-3′-carboxylic acids,esters of 8-cyano-5-methyl-3-oxo-7-(4-pyridyl)-2,3-dihydro-7H-thiazolo-[3,2-a]pyridine-6-carboxylic acids, methyl 3-amino-2-carbamoyl-6-methyl-4-(4-pyridyl)-4,7-dihydrothieno[2,3-b]pyridine-5-carboxylate, and methyl 3-amino-2-carbamoyl-6-methyl-4-(4-pyridyl)-thieno[2,3-b]pyridine-5-carboxylate were synthesized as standard compounds (typical impurities). Analysis by HPLC was realized under the conditions of reverse-phase chromatography. It was established that solutions of the investigated compounds (with mixtures of acetonitrile with phosphate buffer, having pH values of not less than 3 and not more than 5, as solvents) are stable for one month when the solutions are stored in a place protected against light. It is also necessary to use chromatographic systems in which the aqueous components have pH 3–5 during determination of the purity of the esters of 6′-carbamoylmethylthio-5′-cyano-2′-methyl-1′,4′-dihydro-4, 4′-bipyridine-3′-carboxylic acid by HPLC in order to separate the analyzed sorbates and their typical impurities more completely. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 841–848, June, 2007.     

Studies on antibacterial agents. I. Synthesis of substituted 6,7-dihydro-1-oxo-1H,5H-benzo[i,j]quinolizine-2-carboxylic acids

A series of substituted 6,7-dihydro-1-oxo-1H,5H-benzo[i,j]quinolizine-2-carboxylic acids was synthesized and tested for antibacterial activities. Among them, 9-fluoro-6,7-dihydro-5-methyl-8-(4-methyl-1-piperazinyl)-1-oxo-1H,5H- benzo[i,j]quinolizine-2-carboxylic acid (OPC-7241) exhibited potent antibacterial activity against gram-positive and -negative bacteria, including Staphylococcus aureus and Pseudomonas aeruginosa, and 9-fluoro-6,7-dihydro-8-(4-hydroxy-1-piperidyl)-5-methyl-1-oxo-1H, 5H-benzo[i,j]quinolizine-2-carboxylic acid (OPC-7251) showed potent activity characteristically against Propionibacterium acnes.     

The synthesis of benzofuroquinolines. IV. Some halobenzofuro[2,3-B]- and [3,2-C]quinoline derivatives

Some 8- or 9-halobenzofuro[2,3-b]quinolines ( 1a , 8-F, 8-C1, 9-F, 9-Cl) and 9-halobenzofuro[2,3-b]quinoline-11-carboxylic acid ( 1b , F, Cl) were synthesized from 6- or 7-halo-3-(2-methoxyphenyl)-2-oxo-1,2-dihydroquino-line-4-carboxylic acids ( 3 ). And, some 9-halo-11(6H)-benzofuro[2,3-b]quinolinone ( 8 , F, Cl, Br) and 2-halo-6(5H)-benzofuro[3,2-c]quinolinone ( 9 , F, Cl, Br) were synthesized from 6-halo-4-hydroxy-3-(2-methoxyphenyl)-2(1H)-quinolinone ( 7 ), and they were converted to the corresponding chlorohalobenzofuroquinolines ( 1c , 9-F, 9-C1, 9-Br, and 2 , F, Cl, Br).     

Photochemistry of furans. Photochemical transformations of some substituted 2-phenyl-3-furylacrylic acids

A number of new substituted 2-phenyl-3-furylacrylic acids (1–14) were synthesized by modified Perkin reaction and separated into their E-and Z-isomers and identified by spectroscopic methods. E-isomers were UV-irradiated under aerobic conditions to give several types of photoproducts, ie substituted naphtho[2,1-b]furancarboxylic acids (B), 2,3-epoxy-2,3-dihydrofuro[3,2-b]pyran-5-ones (C), 7a - hydroxy - 3a,7a - dihydrofuro[3,2 - b]pyran - 5 - ones (D) and 7a - hydroperoxy - 3a,7a - dihydrofuro[3,2 - b]pyran - 5 - one (E) were recognized. The type of product and yield are strongly substituent-dependent.     

Synthesis and investigation of the stability of esters of 6′-carbamoylmethylthio-5′-cyano-1′,4′-dihydro-3,4′-and-4,4′-bipyridine-3′-carboxylic acids 1. Esters of 6′-carbamoylmethylthio-5′-cyano-1′,4′-dihydro-3,4′-bipyridine-3′-carboxylic acids

Esters of 6′-carbamoylmethylthio-5′-cyano-1′,4′-dihydro-3,4′-bipyridine-3′-carboxylic acids are obtained by the alkylation of piperidinium 3′-alkoxycarbonyl-5′-cyano-1′,4′-dihydro-3,4′-bipyridine-6′-thiolates with iodoacetamide. For an HPLC study of the stability of solutions of the abovementioned 1,4-dihydrobipyridines (solution pH 2.3–9.0) the appropriate esters of 6′-carbamoylmethylthio-5′-cyano-3,4′-bipyridine-3′-carboxylic acids and esters of 8-cyano-5-methyl(or phenyl)-3-oxo-7-pyridin-3-yl-2,3-dihydro-7H-thiazolo[3,2-a]pyridine-6-carboxylic acids were synthesized as reference compounds. Analysis by HPLC was carried out under conditions of reverse-phase chromatography. It was shown that solutions of the investigated compounds in a mixture of acetonitrile and phosphate buffer (pH 3.0–5.0) were stable for 1 month on storage protected from light. Under the action of light in all the solutions investigated irrespective of pH the formation occurs of the corresponding esters of 6′-carbamoylmethylthio-5′-cyano-3,4′-bipyridine-3′-carboxylic acids. The presence of esters of 8-cyano-5-methyl(or phenyl)-3-oxo-7-pyridin-3-yl-2,3-dihydro-7H-thiazolo[3,2-a]pyridine-6-carboxylic acids (no more than 4%) was detected only in 0.1% solutions of phosphoric acid (pH 2.3) under conditions of storage of the latter protected from light. A series of as yet unidentified products was detected in solutions of pH 7.0–9.0. Dedicated to E. Lukevics on his 70th birthday __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 59–68, January, 2007.     

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.     

Synthesis of 5,8-dihydro-5-oxo-2-(3- or 4-pyridinyl)-pyrido[2,3-d]pyrimidine-6-carboxylic acids and the reinvestigation of the thermal cyclization of diethyl (2-hydroxy-4-pyrimidinyl)amino-methylenemalonate

Diethyl [2-(3- or 4-pyridinyl)-4-pyrimidinyl]aminomethylenemalonates 5 prepared by the reaction between 2-(3- or 4-pyridinyl)-4-pyrimidinamines 3 and diethyl ethoxymethylenemalonate ( 4 ) were thermally cyclized to afford ethyl 5,8-dihydro-5-oxo-2-(3- or 4-pyridinyl)pyrido[2,3-d]pyrimidine-6-carboxylates 6 . The later were alkylated with ethyl iodide and then saponified to give 5,8-dihydro-8-ethyl-5-oxo-2-(3- or 4-pyridinyl)pyrido-[2,3-d]pyrimidine-6-carboxylic acids 2 . Thermal cyclization of diethyl (2-hydroxy-4-pyrimidinyl)amino-methylenemalonate ( 8 ) gave ethyl 1,6-dihydro-4,6-dioxo-4H-pyrimido[1,6-a]pyrimidine-3-carboxylate ( 10 ) instead of ethyl 5,8-dihydro-2-hydroxy-5-oxopyrido[2,3-d]pyrimidine-6-carboxylate ( 9 ) as previously claimed.     

Furopyridines. XX. Wittig-horner reaction of a phosphonate of reissert analogues of furo[3,2-c]-, -[2,3-c]- and -[3,2-b]pyridines

Furo[3,2-c]-( 1a ), -[2,3-c]- ( 1b ) and -[3,2-b]pyridine ( 1c ) were reacted with isopropyl chloroformate and trimethyl phosphite to give dimethyl 5-isopropoxycarbonyl-4,5-dihydrofuro[3,2-c]pyridine-4-phosphonate ( 2a ), dimethyl 6-isopropoxycarbonyl-6,7-dihydrofuro[2,3-c]pyridine-7-phosphonate ( 2b ) and dimethyl 4-isopropoxycarbonyl-4,7-dihydrofuro[3,2-b]pyridine-7-phosphonate ( 2c ) as unstable syrups. Reaction of 2b and 2c with n-butyllithium and then with benzaldehyde, p-methoxybenzaldehyde, p-cyanobenzalde-hyde or propionaldehyde afforded the normal Wittig reaction products 5b-H, 5b-OMe, 5b-CN, 5b-Et, 5c-H, 5c-H, 5c-OMe and 5c-CN , except for 2b with propionaldehyde. While, the same reactions of compound 2a and the reaction of 2b with propionaldehyde afforded the unexpected products, 5-isopropoxycar-bonylfuro[3,2-c]pyridinio-4-aryl-(or ethyl)methoxides 3a-H, 3a-OMe, 3a-CN and 3a-Et , 4-(1′-aryl(or ethyl)-1′-hydroxymethyl)furo[3,2-c]pyridines 4a-H, 4a-OMe, 4a-CN and 4a-Et accompanying formation of the normal products. Treatment of the normal Wittig reaction products with lithium diisopropylamide and then with acetone gave the derivatives alkylated at the 2-or the benzylic positions.     

Retinoidal pyrimidinecarboxylic acids. Unexpected diaza-substituent effects in retinobenzoic acids

Several pyridine- and pyrimidine-carboxylic acids were synthesized as ligand candidates for retinoid nuclear receptors, retinoic acid receptors (RARs) and retinoic X receptors (RXRs). Although the pyridine derivatives, 6-[(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)carbamoyl]pyri dine-3-carboxylic acid (2b) and 6-[(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)carboxamido]py ridine-3-carboxylic acid (5b) are more potent than the corresponding benzoic acid-type retinoids, Am80 (2a) and Am580 (5a), the replacement of the benzene ring of Am580 (5a), Am555 (6a), or Am55 (7a) with a pyrimidine ring caused loss of the retinoidal activity both in HL-60 cell differentiation assay and in RAR transactivation assay using COS-1 cells. On the other hand, pyrimidine analogs (PA series, 10 and 11) of potent RXR agonists (retinoid synergists) with a diphenylamine skeleton (DA series, 8 and 9) exhibited potent retinoid synergistic activity in HL-60 cell differentiation assay and activated RXRs. Among the synthesized compounds, 2-[N-n-propyl-N-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)a mino]pyrimidine-5-carboxylic acid (PA013, 10e) is most active retinoid synergist in HL-60 assay.     

Investigation of phenanthridone and dioxotetrahydrodiazapyrene. 4. Synthesis of amino-substituted phenanthridones and dioxotetrahydrodiazapyrenes

The corresponding mono-, di-, and triamino derivatives substituted in the 2, 4, and 8 positions of the phenanthridone ring were obtained by reduction of mono-, di-, and trinitro-substituted phenanthridone (I), phenanthridone-10-carboxylic acid (II), phenanthridone-1-carboxylic acid (III), 4H-cyclopenta[k,l,m]phenanthridine-5,9-dione (IV), 4H-cyclopenta[k,l,m]phenanthridin-5-one (V), 5,10-dioxo-4,5,9,10-tetrahydro-4,9-diazapyrene (VI), and 5,9-dioxo-4,5,9,10-tetrahydro-4,10-diazapyrene (VII) with powdered iron in an electrolyte medium, with hydrogen in the presence of a nickel catalyst, or with stannous chloride. The 2,4,7,9-tetraamino derivative of VI was similarly obtained. 1-Amino-, 7-amino-, and 10-amino-phenanthridones were obtained by the Schmidt reaction from the corresponding carboxylic acids. 1,10-Diamino-, and 3,8-diaminophenanthridones were similarly obtained from the corresponding aminofluorenones.See [1] for Communication 3.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 394–397, March, 1981.     

Cyclisation of 4-[2-Cyclofentenyl]-3-Hydroxy [1] Benzopypan-2-One

4-[2-cyclopentenyl]-3-hydroxy [1] bonzopyran-2-one(3) was cyclised to the bicyclie coumar in-1,3-ethano-2-bromo-1,2-dihydro-3H-pyrano [2,3-c] [1] benzopyran-5-one (6) by a sequence of reactions viz. acetylation of 3, addition of bromine to cyclopenteny double bond and treating the resulting acetyldibromo compound (5) with 4% alcoholic KOH, Cyclisation of compound (3) with mercuric acetate in methanol gave condensed furan derivative 7 which on reductive demercuration with zinc borohydride in dimethoxyethane gave the 1,3-propano-1,2-dihydrofuro [2,3-c] [1] benzopyran-4-one, 8. Cyclisation of compound 2 with come. H₂SO₄ furnished a mixture of bicyclic derivative 9 ad furo coumarin derivative 8.