Synthesis and characterization of novel 2-(1-benzyl-3-[4-fluorophenyl]-1H-pyrazol-4-yl)-7-fluoro-4H-chromen-4-one derivatives

Novel 1-benzyl-3-(4-fluorophenyl)-1H-pyrazole-4-carbaldehydes 3a to 3e were synthesized via Vilsmeier-Haack reaction of the appropriate 1-benzyl-2-(1-(4-fluorophenyl)ethylidene)hydrazines, derived from 4-fluoroacetophenone 1 with substituted 2-benzylhydrazines 2a to 2e . The base catalyzed condensation of 1-benzyl-3-(4-fluorophenyl)-1H-pyrazole-4-carbaldehydes 3a to 3e with 1-(4-fluoro-2-hydroxyphenyl)ethanone 4 gave (E)-3-(1-benzyl-3-(4-fluorophenyl)-1H-pyrazol-4-yl)-1-(4-fluoro-2-hydroxyphenyl)prop-2-en-1-ones 5a to 5e . On cyclization with dimethyl sulfoxide (DMSO)/I₂, compounds 5a to 5e gave 2-(1-benzyl-3-(4-fluorophenyl)-1H-pyrazol-4-yl)-7-fluoro-4H-chromen-4-ones 6a to 6e . Structures of all novel compounds were confirmed by infrared (IR), proton nuclear magnetic resonance (¹H NMR), carbon nuclear magnetic resonance (¹³C NMR), and mass spectral data. All the synthesized compounds were screened for their antibacterial activities.     

(3-苄基-4-芳酰基-1,2,4-三唑-5-基)(5-本基-1,3,4-噁二唑-2-基)硫醚的合成

通过3-苄基-4-芳酰基-1,2,4-三唑-5-巯基负离子在2-甲磺酰基-5-苯基-1,3,4-噁二唑环2-位上的亲核取代反应,制得13个新的(3-苄基-4-芳酰基-1,2,4-三唑-5-基)(5-苯基-1,3,4-噁二唑-2-基)硫醚衍生物.经元素分析、IR、~1H NMR和MS裂解碎片分析确认结构.初步观察了它们在0.01％浓度时对大肠杆菌繁殖的抑制作用.     

Crystal structure and quantum chemical calculations of (E)1-benzyl-3-((4-methoxyphenyl)imino)-5-methylindolin-2-one

The known Schiff base compound, (E)1-benzyl-3-((4-methoxyphenyl)imino)-5-methylindolin-2-one, was prepared as before by reacting 1-benzyl-5-methylindoline-2,3-dione with 4-methoxyaniline. The product was unambiguously characterized using elemental analysis, ¹H and ¹³C-NMR spectroscopy, and its new single-crystal X-ray structural analysis. Molecular orbital calculations were conducted in order to investigate the structures and relative stabilities of the (E) and (Z) isomers of 1-benzyl-3-([4 methoxyphenyl]-imino)-5-methylindolin-2-one. Specific attention was paid to the (E) isomer. The available crystallographic experimental data for the latter ensured also validation of the model structures computationally derived at the theoretical B3LYP/6-31G(d,p) level.     

4-Substituted 5-nitroisoquinolin-1-ones from intramolecular Pd-catalysed reaction of N-(2-alkenyl)-2-halo-3-nitrobenzamides

4-Methyl- and 4-benzyl-5-aminoisoquinolin-1-ones are close analogues of the water-soluble PARP-1 inhibitor 5-AIQ. Their synthesis was approached through Pd-catalysed cyclisations of N-(2-alkenyl)-2-iodo-3-nitrobenzamides. Reaction of N,N-diallyl-2-iodo-3-nitrobenzamide with Pd(PPh₃)₄ gave a mixture of 2-allyl-4-methyl-5-nitroisoquinolin-1-one and 2-allyl-4-methylene-5-nitro-3,4-dihydroisoquinolin-1-one. N-Benzhydryl-N-cinnamyl-2-iodo-3-nitrobenzamide similarly gave 2-benzhydryl-4-benzyl-5-nitroisoquinolin-1-one and 2-benzhydryl-4-benzylidene-5-nitro-3,4-dihydroisoquinolin-1-one. The isomeric products are not interconvertible. A deuterium-labelling study indicated that the isomers were formed by different pathways: a π-allyl-Pd route and the classical Heck route. The corresponding secondary amides N-allyl-2-iodo-3-nitrobenzamide and N-((substituted)-cinnamyl)-2-iodo-3-nitrobenzamide gave good yields of the required 4-methyl- and 4-((substituted)-benzyl)-5-nitroisoquinolin-1-ones, respectively, under optimised conditions (Pd(PPh₃)₄, Et₃N, Bu₄NCl, 150 °C, rapid heating). Hydrogenation of the nitro groups gave 4-methyl- and 4-benzyl-5-aminoisoquinolin-1-ones, which were potent inhibitors of PARP-1 activity.     

Substituted pyridines 5-methyl-4-benzyl-2-styryl(phenylethynyl)pyridines

5-Methyl-4-benzyl-2-styrylpyridine (II), its p-dimethylaminostyryl analog IV, and 5-methyl-4-benzyl-2-(1,3-dioxo-2-hydrindenyl)pyridine (V) have been prepared. II has been converted into 5-methyl-4-benzyl-2-phenylethynylpyridine (VII), 5-methyl-4-benzylpyridine-2-carboxylic acid (VIII), and 3-styryl-6, 7-benzoisoquinoline (X).Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1228–1231, September, 1970.     

S-烷基-O-(2,6-二氯-4取代苯基)硫代磷(膦)酸酯的合成及杀菌活性的研究

O,O-二烷基硫酮代磷(膦)酸酯(3)与三氯氧磷发生异构化氨化反应得到S-烷基硫代磷(膦)酰氨(4),4与2,6-二氯-4-取代苯酚反应,合成了26种新的标题化合物.生物活性初步测定结果表明,这些化合物均有一定的杀菌活性.     

Synthesis and photochromic and fluorescence properties of 3-(1-benzyl-5-methoxy-2-methylindolyl)-4-thienyl-substituted furan(pyrrole)-2,5-diones

New nonsymmetrical dihetarylethenes, 3-(1-benzyl-5-methoxy-2-methyl-1H-indol-3-yl)-4-(3-thienyl)furan-2,5-dione and 1-alkyl- and (1-aryl)-3-(1-benzyl-5-methoxy-2-methyl-1H-indol-3-yl)-4-(3-thienyl)-1H-pyrrole-2,5-dione, exhibiting photochromic properties in solutions were synthesized. Noncyclic isomers of dihetarylethenes show fluorescence with quantum yields up to 0.13.     

Ring transformations of aziridinyl 2-phosphonates: synthesis of 5-phosphono-2-oxazolidinones and 5-phosphono-2-imidazolidinones

Syntheses of 5-phosphono-2-oxazolidinones and 5-phosphono-2-imidazolidinones were achieved from the corresponding 1-vinyl-2-phosphonoaziridines. Regioselective aziridine ring opening employing methyl chloroformate affords 1-amido-2-chloroethylphosphonates, which were easily transformed into the corresponding 2-oxazolidinones upon heating in dimethyl sulfoxide. Treatment of the aziridine ring opening products with ammonia furnishes vinylphosphonates, which undergo a Michael type addition with several amines. In situ ring closure of the addition products yields the corresponding phosphonylated 2-imidazolidinones.     

Synthesis and cytotoxic activity of some 3-benzyl-5-arylidenefuran-2(5H)-ones

3-Benzyl-furan-2(5H)-one (2a) and 3-(4-bromobenzyl)-furan-2(5H)-one (2b) were treated with TBDMSOTf and converted into the corresponding tert-butyldimethyl-silylfuran ethers. These furans were further condensed with several aromatic aldehydes affording compounds 5-14 with general 3-benzyl-5-arylidene-furan-2(5H)-one structures in 31% to 98% yields. Such compounds are analogues of the naturally occurring nostoclide lactones, reported to present moderate cytotoxic activity. Compounds 5-14 were submitted to an in vitro bioassay against the HL-60, HCT-8, SF295 and MDA-MB-435 cancer cell lines using the MTT cytotoxicity assay.     

Self-catalytic Michael reaction of enolizable carbonyl compounds. A facile route to α-methylene-δ-valerolactones

Various dicyclohexylammonium 2-phosphono-5-oxoalkanoates 3 were prepared by the Michael reaction of enolizable carbonyl compounds with the acrylate 1. The corresponding 2-phosphono-5-oxoalkanoic acids 4 were converted into α-phosphono-δ-valerolactones 6. The products were shown to be useful substrates for the synthesis of α-methylene-δ-valerolactones 7 by the Horner-Wadsworth-Emmons reaction.     

Highly selective synthesis of 4(5)-aryl-, 2,4(5)-diaryl-, and 4,5-diaryl-1H-imidazoles via Pd-catalyzed direct C-5 arylation of 1-benzyl-1H-imidazole

Highly selective, practical, and efficient protocols for the preparation of 4(5)-aryl-1H-imidazoles 2, 2,4(5)-diaryl-1H-imidazoles 3, and 4,5-diaryl-1H-imidazoles 1 are described. A key step of these protocols is the regioselective synthesis of 5-aryl-1-benzyl-1H-imidazoles 9 by Pd-catalyzed direct C-5 arylation of commercially available 1-benzyl-1H-imidazole (8) with aryl halides. The three-step synthesis of compounds 3 from 8 also involves the Pd-catalyzed and Cu-mediated direct C-2 arylation of imidazoles 9 with aryl halides under base-free and ligandless conditions. On the other hand, the four-step synthesis of imidazoles 1 from 8 also involves the regioselective bromination of compounds 9 and a Suzuki reaction of the resulting 5-aryl-1-benzyl-4-bromo-1H-imidazoles 11 with arylboronic acids 5 under phase-transfer conditions, followed by N-debenzylation.     

Synthesis of analogs of 5(4)-aminoimidazole-4(5)-carboxamide and purines. 9. peculiarities of the reaction of 5(4)-aminoimidazole-4(5)-carboxhydrazide with nitrous acid and of 5-diazoimidazole-4-carboxazide with amines

The reaction of 5(4)-aminoimidazole-4(5)-carboxhydrazide with nitrous acid was investigated. A mixture of four compounds, viz., 5-diazoimidazole-4-carboxazide, 5-diazoimidazole-4-carboxylic acid, 5(4)-aminoimidazole-4(5)-carboxazide, and 2-azahypoxanthine, is formed under all of the investigated conditions, 5(4)-Azidoimidazole-4(5)-carboxamide derivatives were obtained in the reaction of diazoimidazole-carboxazide with various amines in protic and aprotic solvents. 5-N-(Piperidyl)-azoimidazole-4-carboxazide was isolated only in the reaction with piperidine in an aqueous medium.See [1] for Communication 8.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1536–1540, November, 1980.     

Synthesis of ribonucleosides of 4(5)-cyano-5(4)-methylimidazole and related 4-substituted-5-methylimidazole ribosides

4-Cyano-1-(2,3,5-tri-O-acetyl-β-D-ribofuranosyl)-5-methylimidazole ( 4 ) and its corresponding 5-cyano-4-methyl substituted isomer ( 5 ) have been obtained by ribosylation of 4(5)-cyano-5(4)-methylimidazole ( 3 ) via the mercuric cyanide method or by ribosylation of the trimethylsilyl derivative of 3 . Treatment of 4 with methanolic ammonia, ammonium chloride in liquid ammonia and potassium hydrosulfide provided 4-cyano-1-β-D-ribofuranosyl-5-methylimidazole ( 6 ), 1-β-D-ribofuranosyl-5-methylimidazole-4-carboxamide ( 2 ) and 1-β-D-ribofuranosyl-5-methylimidazole-4-thiocarboxamide ( 11 ) respectively. Reaction of 6 with hydroxylamine afforded the corresponding 4-carboxamidoxime substituted nucleoside ( 13 ) which on catalytic reduction in the presence of ammonium chloride, was transformed into 1-β-D-ribofuranosyl-5-methylimidazole-4-carboxamidine ( 14 ) as hydrochloride salt.     

Synthesis of analogs of 5(4)-aminoimidazole-4(5)-caeboxamide and purines

4(5)-Sulfonyl chlorides, which were converted to the corresponding sulfamoyl derivatives, were obtained from the amide and ethyl ester of 4(5)-mercaptoimidazole-5(4)-carboxylic acid by oxidative chlorination. The azide of 4(5)-sulfamoylimidazole-5(4)carboxylic acid was synthesized through 4(5)-sulfamoylimidazole-5(4)-carboxylhydrazide, and its conversion in various media to 5(4)-aminoimidazole-4(5)-sulfonamide derivatives and to 3,4-dihydro-3-oxoimidazo[4,5-e]-1,2,4-thiadiazine 1,1-dioxide was studied.See [1] for communication V.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1119–1122, August, 1976.     

Lactams—I The synthesis and acid hydrolysis of 4- and 5-substituted 1-benzyl-2-piperidone derivatives

In order to explain the difficulty in hydrolysing the lactam linkage of 1-benzyl-2-oxo-5-ethyl-4-piperidineacetic acid (XIV) under acid conditions, several model compounds such as 1-benzyl-2-piperidone (X), 1-benzyl-5-ethyl-2-piperidone (XI), 1-benzyl-4-ethyl-2-piperidone (XII) and 1-benzyl-2-oxo-4-piperidineacetic add (XIII) were prepared and their hydrolysis in boiling 6N HCl was studied. For each of the lactams, the hydrolysis was found to proceed to an equilibrium as shown in Table 1. Substituents at the 4- and 5-positions of the piperidone ring seemed to favour the ring form in the equilibrium between piperidones (X-XIV) and ω-amino acid hydrochlorides (type XV).     

Synthese von 4(5)-acyl-5(4)-alkylimidazolen aus symmetrischen 1,3-dicarbonylverbindungen

Synthesis of 4(5)-Acyl-5(4)-alkylimidazoles from Symmetrical 1,3-Diones A new synthesis of 4(5)-acyl-5(4)-alkylimidazoles 1 is described. The symmetrical 1,3-diones 5a and 5b were reacted with N₂O₄ to give the nitro compounds 7a and 7b , respectively; 5c was treated with NaNO₂ to give the nitroso compound 7c (Scheme 2). Hydrogenation of 7a , 7b and 7c over Pd/C in acetic acid/acetic formic anhydride yielded the formamides 9a , 9b and 9c , whose cyclization in formamide/formic acid afforded the 4(5)-acyl-5(4)-alkylimidazoles 1a, 1b and 1c , respectively. Oxazoles 11a and 11b were obtained from the corresponding formamides 9a and 9b with methanesulfonic acid/P₂O₅.     

General synthetic route to benz[g]isoquinolines (2-azaanthracenes)

Benzylic zinc reagents add with high regioselectivity to 1-(phenoxycarbonyl) salts derived from pyridine-3-carboxaldehyde ( 1a ) or 3-acetylpyridine ( 1b ) to yield 1-(phenoxylcarbonyl)-4-benzyl-1,4-dihydropyridine-3-carboxaldehydes 5a, 5c or ketones 5b, 5d . Aromatizations of these dihydro analogues with sulfur led to the corresponding aldehydes 6a, 6c or ketones 6b, 6d . An alternate synthesis to the aldehydic precursors involved additions of benzylic zinc reagents to 1-(phenoxycarbonyl) salts formed from methyl nicotinates which led to the corresponding methyl 1-(phenoxycarbonyl)-4-benzyl-1,4-dihydronicotinates 7a, 7b . Aromatizations of 7a, 7b led to the corresponding pyridine esters 8a, 8b which on reduction with lithium aluminum hydride yielded the corresponding carbinols 9a, 9b . Oxidation of 9a, 9b by manganese dioxide afforded aldehydes 6e, 6f . Aldehydes 6a-f were readily converted into the benz[g]isoquinolines 10a-f on heating in polyphosphoric acid.     

Acetals of lactams and acid amides. 40. Synthesis and hydrolytic cleavage of one-ring and two-ring derivatives of 4-pyrimidinone

The reaction of 1-benzyl-5-cyano-6-dimethylaminomethylene-1, 6-dihydro-4-pyrimidinone with acid leads to 5-benzyl-1,2,7,8-tetrahydropyrido[4,3-d]pyrimidine-1,8-dione, whereas the reaction with ammonia leads to a mixture of 3-cyano-4-benzylamino-2-pyridone and 1-amino-5-benzyl-7,8-dihydropyrido[4,3-d]-pyrimidin-8-one. Heating of the latter in aqueous ethylene glycol is accompanied by recyclization to give 4-benzylamino-5,6-dihydropyrido[2,3-d]pyrimidin-5-one. The reaction of 1-benzyl-4-ditnethylaminomethylene-5-cyano-1,6-dihydro-6-pyrimidinone with ammonia leads to 1-amino-7-benzyl-7,8-dihydropyrido[4,3-d]-pyrimidin-8-one. The rate constants for cleavage of the pyrimidine ring in a number of 4-pyrimidinone derivatives were measured.See [1] for communication 39.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 532–537, April, 1984.     

Synthesis and Antitumor Activity of 4-tert-Butyl-5-benzyl-2-benzyliminothiazoles

A series of novel Schiff bases including 4-tert-butyl-5-benzyl-2-benzyliminothiazoles was synthesized by reacting the aromatic aldehydes with the corresponding 2-aminothiazoles.The antitumor bioassay revealed that compounds 2n and 2m exhibited potent cytotoxicity against human cervix cancer（HeLa） cell line with IC50 values of 0.001 and 0.007 mmol/L,respectively.The preliminary structure-activity relationship（SAR） investigations and the apoptosis evaluation suggest that 4-tert-butyl-5-benzyl-2-benzyliminothiazoles may be a satisfactory backbone for antitumor activity,and compound 2n can serve as an attractive candidate for the development of novel apoptosis in anticancer treatment.     

Bildung von 5,6-Dihydro-1,3(4H)-thiazin-4-carbonsäure-estern aus 4-Allyl-1,3-thiazol-5(4H)-onen

Formation of Methyl 5,6-Dihydro-l, 3(4H)-thiazine-4-carboxyiates from 4-Allyl-l, 3-thiazol-5(4H)-ones . The reaction of N-[1-(N, N-dimethylthiocarbamoyl)-1-methyl-3-butenyl]benzamid ( 1 ) with HCl or TsOH in MeCN or toluene yields a mixture of 4-allyl-4-methyl-2-phenyl-1,3-thiazol-5(4H)-one ( 5a ) and allyl 4-methyl-2-phenyl-1,3-thiazol-2-yl sulfide ( 11 ; Scheme 3). Most probably, the corresponding 1,3-oxazol-5(4H)-thiones B are intermediates in this reaction. With HCl in MeOH, 1 is transformed into methyl 5,6-dihydro-4,6-dimethyl-2-phenyl-1,3(4H)-thiazine-4-carboxylate ( 12a ). The same product 12a is formed on treatment of the 1,3-thiazol-5(4H)-one 5a with HCl in MeOH (Scheme 4). It is shown that the latter reaction type is common for 4-allyl-substituted 1,3-thiazol-5(4H)-ones.