2-[3-(Trifluoromethyl)phenyl]furo[3,2-b]pyrroles: synthesis and reactions

The synthesis and reactions of methyl 2-[3-(trifluoromethyl)phenyl]-4H-furo[3,2-b]pyrrole-5-carboxylate (1a) are described. Upon reaction with methyl iodide, benzyl chloride, or acetic anhydride, this compound gave N-substituted products 1b-d. By hydrolysis of compounds 1a-c, the corresponding acids 2a-c were formed, or by reaction with hydrazine-hydrate, the corresponding carbohydrazides 3a-c were formed. By heating 2-[3-(trifluoromethyl)phenly]-4H-furo[3,2-b]pyrrole-5-carboxylic acid (2a) in acetic anhydride, 4-acetyl-2-[3-(trifluoromethyl)phenyl]furo[3,2-b]pyrrole (4) was formed. By hydrolysis of 4, 2-[3-(trifluoromethyl)phenyl]-4H-furo[3,2-b]pyrrole (5a) was formed, and reactions with methyl iodide or benzyl chloride gave N-substituted products 5b-c. The reaction of 4 with dimethyl butynedioate gave substituted benzo[b]furan 6. Compound 3a reacted with triethyl orthoesters giving 7a-c, which afforded with phosphorus (V) sulphide the corresponding thiones 8a-c. The thiones 8a-c reacted with hydrazine hydrate to form hydrazine derivatives 9a-c. The reaction of triethyl orthoformiate with compounds 9a-c led to furo[2′,3′: 4,5]pyrrolo[1,2-d][1,2,4]triazolo[3,4-f][1,2,4]triazines 10a-c. Hydrazones 11a-c were formed from 3a-c and 5-[3-(trifluoromethyl)phenyl]furan-2-carboxaldehyde. The effect of microwave irradiation on some condensation reactions was compared with “classical” conditions. The results showed that microwave irradiation shortens the reaction time while affording comparable yields.     

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.     

Synthesis of potential impurities of dabigatran etexilate

The present work describes the origin, control, and synthesis of two potent impurities of dabigatran etexilate 1, dabigatran dimer 2, and dabigatran n-propyl ester 3 from the commercially available raw materials 2-[(4-cyanophenyl)amino]acetic acid (4) and N-[3-amino-4-(methylamino)benzoyl]-N-2-pyridinyl-β-alanine ethyl ester (5). These impurities are the process-related impurities and may affect the quality of drug substance, during its manufacturing in large scale. These impurities are not only the crucial components in determining the quality and safety of the drug substance 1 but also provide a better understanding of impurity profiling.     

水溶性稠杂环均三唑并噻二唑体系的合成及生物活性(I): 哌嗪取代衍生物

4-氨基-5-吡啶-4-基-均三唑硫醇(1)在复合催化剂DMAP和TBAB作用下与对卤代苯甲酸经环缩合反应以高收率得到中间体6-(5-氯-3-甲基-1-取代苯基-1H-吡唑-4-基)-3-吡啶-3-基-均三唑并[3,4-b][1,3,4]噻二唑(2a～2c), 接着苯环卤原子与取代哌嗪在聚乙二醇催化作用下发生亲核取代反应得到相应的哌嗪游离碱(3a～3c). 其中, 单取代哌嗪游离碱3a与含功能基的卤代物缩合得到功能基取代的哌嗪衍生物(4a～4g). 这些产生的游离碱与盐酸反应得到相应的水溶性盐酸盐. 所合成新化合物的结构经元素分析和光谱数据表征, 并评价了它们的体外抗菌活性及构效关系.     

Evidence of Hydrogen Bonding in Stabilizing the Cone Conformation of a Monoalkylated Calix[4]arene. X-ray Structure of 25-[2-(ethoxy-1-p-toluene-sulfonate)phenyl]-26,27,28-trihydroxy calix[4]arene

The synthesis of25-[2-(ethoxy-1-p-toluene-sulfonate)phenyl]-26,27,28-trihydroxy calix[4]arene3 as a byproduct of the preparation of 1,3-dialkylated25,27-di-[2-(ethoxy-1p-toluene-sulfonate)phenyl]-26,28-dihydroxy calix[4]arene 2 is reported. Compound 3 is a monoalkylatedcalix[4]arene in the cone conformation. The X-ray structure of 3 showed that this conformation is stabilized by intramolecular hydrogen bonding.     

Ni(II) and Cu(II) complexes of new unsymmetrical N2O2 Schiff bases derived from 3-(2-aminobenzylimino)-1-phenylbutan-1-ol: synthesis,structure, antibacterial properties,and electrochemistry

Two new N₂O₂ unsymmetrical Schiff bases, H₂L¹ = 3-[({o-[(E)-(o-hydroxyphenyl)methylideneamino]phenyl}methyl)imino]-1-phenyl-1-buten-1-ol and H₂L² = 3-[({o-[(E)-(2-hydroxy-1-naphthyl)methylideneamino]phenyl}methyl)imino]-1-phenyl-1-buten-1-ol, and their copper(II) and nickel(II) complexes, [CuL¹] (1), [CuL²] (2), [NiL¹] (3), and [NiL²] (4), have been synthesized and characterized by elemental analyses and spectroscopic methods. The crystal structures of these complexes have been determined by X-ray diffraction. The coordination geometry around Cu(II) and Ni(II) centers is described as distorted square planar in all complexes with the CuN₂O₂ coordination more distorted than the Ni ones. The electrochemical studies of these complexes indicate a good correlation between the structural distortion and the redox potentials of the metal centers. The ligand and metal complexes were also screened for their in vitro antibacterial activity.     

Succinct and Facile Synthesis of Innovative Thiopyrimidines With Antimicrobial and Antitubercular Investigation

Abstract

To develop a series of bioactive heterocycles in minimum number of steps, 3-methyl- 4-(substituted phenyl)-1-phenyl-4,8-dihydropyrazolo[4′,3′:5,6]pyrano[2,3-d]pyrimidine-5,7 (1H,6H)-dithione 2(a–j), 4-(4-substituted phenyl)-5-imino-3-methyl-1,6-diphenyl-4,5,6,8-tetrahydropyrazolo[4′,3′:5,6]pyrano[2,3-d]pyrimidine-7(1H)-thione 3(a–j), and N-[4-(subs- tituted phenyl)-3-methyl-1-phenyl-7-thioxo-1,4,7,8-hexahydropyrazolo[4′,3′:5,6]pyrano[2,3-d]pyrimidine-5-yl]thiourea 4(a–j) have been synthesized from amino nitrile functionality 1(a–j). The structures of the compounds were elucidated by IR, ¹H NMR, elemental analysis, and some representative ¹³C NMR and mass spectra. All the title compounds were screened for antimicrobial and antitubercular activities, while some representative compounds were tested for antioxidant activity. Out of synthesized compounds, compounds 1j (4-CH₃), 2d (4-F), 4c (4-OH), and 4i (3-Br) exhibited maximum inhibition against Mycobacterium Tuberculosis H₃₇Rv. Compound 3c (4-OH) revealed elevated efficacy against all tested bacterial strain, while compounds 1i (3-Br), 2c (4-OH), and 3h (3-NO₂) were found efficacious against Candida albicans as compared to standard drugs.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Synthesis of 1-methyl-7-(trifluoromethyl)-1H-pyrido[2,3-c][1,2]thiazin-4(3H)-one 2,2-dioxide

The reaction of methyl 2-bromo-6-(trifluoromethyl)-3-pyridinecarboxylate ( 1 ) with methanesulfonamide gave methyl 2-[(methylsulfonyl)amino]-6-(trifluoromethyl)-3-pyridine-carboxylate ( 2 ). Alkylation of compound 2 with methyl iodide followed by cyclization of the resulting methyl 2-[methyl(methylsulfonyl)amino]-6-(trifluoromethyl)-3-pyridinecarboxylate ( 3 ) yielded 1-methyl-7-(trifluoromethyl)-1H-pyrido[2,3-c][1,2]thiazin-4(3H)-one 2,2-dioxide ( 4 ). The reaction of compound 4 with α,2,4-trichlorotoluene, methyl bromopropionate, methyl iodide, 3-trifluoromethylphenyl isocyanate, phenyl isocyanate and 2,4-dichloro-5-(2-propynyloxy)phenyl isothiocyanate gave, respectively, 4-[(2,4-dichlorophenyl)methoxy]-1-methyl-7-(trifluoromethyl)-1H-pyrido[2,3-c][1,2]thiazine 2,2-dioxide ( 5 ), methyl 2-[[1-methyl-2,2-dioxido-7-(trifluoromethyl)-1H-pyrido[2,3-c][1,2]thiazin-4-yl]oxy]propanoate ( 6 ), 1,3,3-trimethyl-7-(trifluoromethyl)-1H-pyrido[2,3-c][1,2]thiazin-4(3H)-one 2,2-dioxide ( 7 ), 4-hydroxy-1-methyl-7-(trifluoromethyl)-N-[3-(trifluoromethyl)phenyl]-1H-pyrido[2,3-c][1,2]thiazine-3-carboxamide 2,2-dioxide ( 8 ), 4-hydroxy-1-methyl-7-(trifluoromethyl)-N-phenyl-1H-pyrido[2,3-c][1,2]thiazine-3-carboxamide 2,2-dioxide ( 9 ) and N-[2,4-dichloro-5-(2-propynyloxy)phenyl]-4-hydroxy-1-methyl-7-(trifluoromethyl)-1H-pyrido[2,3-c][1,2] thiazine-3-carboxamide 2,2-dioxide ( 10 ).     

α,β,γ,δ-四-{4-[3-(9-(4-(3-(9-(4-(2-(5,5-二酰氧基甲基-1,3-二噁烷基))))苯基-2,4,8,10-四氧杂螺[5.5]十一烷基)))苯基-2,4,8,10-四氧杂螺[5.5] 十一烷基]}苯基卟啉星形化合物的合成

以对苯二甲醛、丙二腈、季戊四醇和吡咯为原料, 合成了含有螺环结构单元的中间体3-[4-(2,2-二氰基)乙烯基]苯基-9-(4-甲酰基)苯基-2,4,8,10-四氧杂螺[5.5]十一烷(3)和α,β,γ,δ-四-(4-甲酰基苯基)卟啉(4). 4与过量的季戊四醇反应, 得到α,β,γ,δ-四-{4-[2-(5,5-二羟甲基-1,3-二噁烷基)]}苯基卟啉(5), 5与3的反应产物经10% NaOH 处理后, 再与过量的季戊四醇反应, 得到α,β,γ,δ-四-{4-[3-(9-(4-(3-(9-(4-(2-(5,5-二羟甲基-1,3-二噁烷基))))苯基-2,4,8,10-四氧杂螺[5.5]十一烷基)))苯基-2,4,8,10-四氧杂螺[5.5]十一烷基]}苯基卟啉(6), 6与乙酐、丙酐、苯甲酰氯反应, 得到α,β,γ,δ-四-{4-[3-(9-(4-(3- (9-(4-(2-(5,5-二乙酰氧基甲基-1,3-二噁烷基))))苯基-2,4,8,10-四氧杂螺[5.5]十一烷基)))苯基-2,4,8,10-四氧杂螺[5.5]十一烷基]}苯基卟啉(7), α,β,γ,δ-四-{4-[3-(9-(4-(3-(9-(4-(2-(5,5-二丙酰氧基甲基-1,3-二噁烷基))))苯基-2,4,8,10-四氧杂螺[5.5]十一烷基)))苯基-2,4,8,10-四氧杂螺[5.5]十一烷基]}苯基卟啉(8)和α,β,γ,δ-四-{4-[3-(9-(4-(3-(9-(4-(2-(5,5-二苯甲酰氧基甲基-1,3-二噁烷基))))苯基-2,4,8,10-四氧杂螺[5.5]十一烷基)))苯基-2,4,8,10-四氧杂螺[5.5]十一烷基]}苯基卟啉(9)等三种卟啉星形化合物. 中间体1～6和星形化合物7～9均进行了IR, ¹H NMR, MS和元素分析等结构表征. 对影响反应的诸因素进行了讨论.      

Synthesis of Pyrano‐ and Pyrido‐Anellated Pyranosides as Precursors for Nucleoside Analogues

The push‐pull activated methyl (3Z)‐4,6‐O‐benzylidene‐3‐[(methylthio)methylene]‐3‐deoxy‐α‐D‐erythro‐hexopyranosid‐2‐ulose (1) reacted with dialkyl malonate in the presence of potassium carbonate to give the alkyl (2R,4aR,6S,10bS)‐4a,6,8,10b‐tetrahydro‐6‐methoxy‐8‐oxo‐2‐phenyl‐4H‐pyrano[3′,2′:4,5]pyrano[3,2‐d][1,3]dioxine‐9‐carboxylates 2 and 3. Treatment of 1 with 3‐oxo‐N‐phenyl‐butyramide, N‐(4‐methoxy‐phenyl)‐3‐oxo‐butyramide, and 3‐oxo‐N‐o‐tolyl‐butyramide, respectively, in the presence of potassium carbonate and 18‐crown‐6 yielded the (2R,4aR,6S,10bS)‐9‐acetyl‐7‐aryl‐4,4a,7,10b‐tetrahydro‐6‐methoxy‐2‐phenyl[1,3]dioxino‐[4′,5′:5,6]pyrano[3,4‐b]pyridin‐8(6H)‐ones 4–6. (2R,4aR,6S,10bS)‐4,4a,8,10b‐Tetrahydro‐6‐methoxy‐8‐oxo‐2‐phenyl‐4H‐pyrano[3′,2′:4,5]pyrano[3,2‐d][1,3]dioxine‐9‐carboxamide (7) was prepared by anellation reactions of 1 either with malononitrile or with cyanoacetamide.     

THE CRYSTAL STRUCTURE OF 2-[(N,N-DIMETHYLAMINO)METHYL]BENZENETELLURENYL CHLORIDE

The crystal structure of 2-[N,N-dimethylamino)methyl]benzenetel-lurenyl chloride (2), a compound previously formulated as bis[[2-(N,N-dimethylamino)methyl]phenyl] ditelluride bis hydrochloride (1a), was determined. In the molecule 2, tellurium is bonded to the carbon of the phenyl group [2.120(3) Å], the nitrogen of the ortho dimethylamino substituent [2.362(3) Å], and the chlorine atom [2.536(1) Å]. There also is an intermolecular interaction of the tellurium atom with the phenyl ring of a neighbouring molecule [3.655(1) Å], resulting in the formation of zigzag chains along the b axis. The noncentrosymmetric space group of the crystal can be explained by the chiral surrounding of tellurium.     

POLYROTAXANE WITH π-CONJUGATED PORPHYRIN AND POLYAZOMETHINE SYSTEMS PREPARED FROM A TYPE OF PORPHYRIN-DIALDEHYDE AND COMPLEX OF β-CYCLODEXTRIN WITH 1,4-PHENYLENEDIAMINE

The synthesis of 5,15-bis[4-(methoxycarbonyl)phenyl]-10,20-diphenylporphyrin (2) and its reduction to 5,15-bis[4-(hydroxymethyl)phenyl]-10,20-diphenylporphyrin (3), and so its oxidation to provide 5,15-bis(4-formylphenyl)-10,20-diphenylporphyrin (4) are reported. The copolymer possessing β-cyclodextrin (β-CD), π-conjugated porphyrin and polyazomethine systems was synthesized by the polycondensation of porphyrin-dialdehyde monomer (4) and β-cyclodextrin/1,4-phenylenediamine complex (5). The monomers and the copolymer were characterized by UV-Vis, 1H-NMR and IR spectra. Furthermore, 1H-NMR and FT-IR spectra confirmed locating the aromatic ring of 1,4-phenylenediamine molecule in the center of β-cyclodextrin cavity.     

Synthesis,Characterization, and Biological Evaluation of Some Novel Thiosemicarbazones as Possible Antibacterial and Antioxidant Agents

Abstract

The synthesis and characterization of 18 novel thiosemicarbazones have been investigated as part of a research program on development of compounds with antibacterial and antioxidant activities. Among the tested compounds, 2-(4-hydroxybenzylidene)-N-[4-(trifluoromethoxy)phenyl]hydrazine carbothioamide (3g) and 2-(thiophen-2-ylmethylidene)-N-[4-(morpholin-4-yl)phenyl]hydrazine carbothioamide (4b) showed excellent inhibition potency at low concentration (0.5 μg/mL) against Gram-positive pathogens (Enterococcus faecalis and Staphylococcus aureus). All tested compounds were also found to possess antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and 2,2’-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation.

[Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental files: Additional text, tables, and figures.]     

Syntheses of enantiopure Si-centrochiral silicon-based muscarinic antagonists using an enantioselective enzymatic esterification as the key step

The muscarinic antagonists (R)-cyclopentyl(hydroxymethyl)phenyl[2-(piperidin-1-yl)ethyl]silane[(R)-1] and(R)-1-{2-[cyclopentyl(hydroxymethyl)phenylsilyl]ethyl}-1-methylpiperidinium iodide [(R)-2] were synthesized using anenantioselective enzymatic transformation as the key step. Apapain-catalyzed (E.C. 3.4.22.2) esterification ofrac-cyclopentyl(hydroxymethyl)phenyl(vinyl)silane(rac-3) with 5-phenylpentanoic acid afforded(R)-cyclopentyl(phenyl)[(5-phenylpentanoyloxy)methyl]vinylsilane[(R)-4] which upon chemical hydrolysis gave enantiomericallyenriched (R)-3 (68% ee). Repetition of thisesterification/hydrolysis sequence, starting from enantiomericallyenriched (R)-3, finally gave the enantiopure silane (R)-3(98% ee) which served as the starting material for thesubsequent chemical synthesis of (R)-1 and (R)-2{(R)-3 (R)-cyclopentyl(phenyl)[(trimethylsilyloxy)methyl]vinylsilane[(R)-5] (R)-1 (R)-2}.     

STEREOCHEMISTRY AND CONFORMATION OF AMIDO-PHOSPHONOCYCLOHEXENE DERIVATIVES,ASSIGNED BY NMR AND X-RAY DIFFRACTION ANALYSES

Stereochemistry (absolute or relative) of four compounds have been established by x-ray diffraction analysis, namely: 3(R)-[4′(R)-(phenyl) oxazolidin-2-one-1-yl]-4(S)-dimethoxyphosphoryl-4-methoxycarbonyl-1-cyclohexene (7), 3(R)-[4′-(R)-(phenyl)-oxazolidin-2-thione-1-yl]-4(S)dimethoxyphosphoryl-4-methoxycarbonyl-1-cyclohexene (8), methyl 1dimethoxyphosphoryl-2-succinimido-3,4-epoxy-cyclohexane-1-carboxylate (9), and 3-succinimido-4-methylcarbonyl-5-dimethoxyphosphoryl-1-cyclohexene (10). The ring conformations deduced from NMR analysis were thus fully confirmed.     

p<Emphasis Type="Italic">K</Emphasis><Subscript>a</Subscript> Determinations for Montelukast Sodium and Levodropropizine

The pK _a constants and relative abundances of unionized and ionized forms of Montelukast sodium {the sodium salt of 2-[1-[[(1R)-1-[3-[2-(7-chloroquinolin-2-yl)ethenyl] phenyl]-3-[2-(2-hydroxypropan-2-yl)phenyl]propyl]sulfanylmethyl]cyclopropyl]acetic acid} and Levodropropizine {(2S)-3-(4-phenylpiperazin-1-yl)propane-1,2-diol} were determined potentiometrically from measurements at various pHs. These determinations were in order to relate their pK _a values with their bioavailability and to provide chemical data to be used in their analysis.     

Synthesis of 3-geranyl- and 3-prenyl-2,4,6-trihydroxybenzophenone

Biologically active phenyl[3-(3,7-dimethyl-2,6-octadienyl)-2,4,6-trihydroxyphenyl]methanone (2) and phenyl[2,4,6-trihydroxy-3-(3-methyl-2-butenyl)phenyl]methanone (3) were synthesized by an efficient and convenient synthetic sequence. The reaction steps of this synthesis included methylation, Friedel-Crafts acylation, demethylation and geranylation steps.     

Heterocyclic Synthesis via Enaminonitriles: an Efficient,One Step Synthesis of Some Novel Azolo[1,5-α]Pyrimidine,Pyrimido[1,2-α]-Benzimidazole,Pyrido[1,2-α]Benzimidazole Pyrimidine and Pyrazole Derivatives

Some novel pyrazolo[1,5-α]pyrimidines 5a-f, 10a,b, 1,2,4-triazolo[1.5-α]-pyrimidine (12), and pyrimido[1,2-α]benzimidazole 18 could be synthesized by reacting 3-(4-chlorophenyl)-2-(N,N-dimethylamino)methylene-3-oxopropanenitrile (2) with 5-amino-3- and/or 4-substituted-1H-pyrazoles 3a-f and 9a,b, 3-amino-1,2,4-triazole (11) and 2-aminobenzimidazole (14), respectively. The reaction of 2 with 1H-benzimidazol-2-ylacetonitrile (19) afforded the pyrido[1,2-α]benzimidazole 20. On the other hand, the reaction of 2 with guanidine, hydrazine, and phenyl hydrazine afforded the pyrimidine 24, and the pyrazoles 27, 28, respectively. However, the reaction of 2 with hydroxyl amine did not afford the isoxazole 32.     

Synthesis of Heteroanellated Pyranosides Starting from Methyl 4,6‐O‐benzylidene‐2,3‐dideoxy‐α‐d‐erythro‐hexopyranosid‐2‐ylidenemalononitrile

The hexopyranosid‐2‐ylidenemalononitrile 1 reacted with phenyl isothiocyanate in the presence of triethylamine to furnish (2R,4aR,6S,10bS)‐8‐amino‐4a,6,10,10b‐tetrahydro‐6‐methoxy‐2‐phenyl‐10‐phenylimino‐4H‐thiopyrano[3′,4′:4,5]pyrano[3,2‐d][1,3]dioxine‐7‐carbonitrile (2). Starting from 1, cyclization with sulphur and diethylamine yielded (2R,4aR,6S,9bR)‐8‐amino‐4,4a,6,9b‐tetrahydro‐6‐methoxy‐2‐phenylthieno[2′,3′:4,5]pyrano[3,2‐d][1,3]dioxine‐7‐carbonitrile (3), which could be transformed into the corresponding aminomethylenamino derivative 4 by treatment with triethyl orthoformate and ammonia. Intramolecular cyclization of 4 to yield (2R,4aR,6S,11bR)‐4,4a,6,11b‐tetrahydro‐6‐methoxy‐2‐phenyl[1,3]dioxino[4″,5″:5′,6′]pyrano[3′,4′:4,5]thieno [2,3‐d]pyrimidin‐7‐amine (5) was achieved by using NaH as base. (2R,4aR,6S,9bS)‐8‐Amino‐4a,6,9,9b‐tetrahydro‐6‐methoxy‐9‐(4‐methylphenyl‐sulfonyl)‐2‐phenyl‐4H‐[1,3]dioxino[4′,5′:5,6]pyrano[4,3‐b]pyrrole‐7‐carbonitrile (6) was prepared by treatment of compound 1 with tosylazide and triethylamine.     

Synthesis and reactions of 2-[3-(trifluoromethyl)phenyl]furo[3,2-<Emphasis Type="Italic">c</Emphasis>]pyridine

(E)-3-{5-[3-(Trifluoromethyl)phenyl]furan-2-yl}propenoic acid (I) was prepared from 5-[3-(tri-fluoromethyl)phenyl]furan-2-carbaldehyde under the Doebner’s conditions. The obtained acid was converted to the corresponding azide II, which was cyclized by heating in diphenyl ether to 2-[3-(trifluoromethyl)phenyl]-4,5-dihydrofuro[3,2-c]pyridin-4-one (III). This compound was aromatized with phosphorus oxychloride to chloroderivative IV which was reduced with H₂NNH₂-Pd/C to the title compound V. 2-[3-(Trifluoromethyl)phenyl]furo[3,2-c]pyridin-5-oxide (VI) was synthesized by reaction of V with 3-chloroperoxybenzoic acid in dichloromethane. On treatment of VI with benzoyl chloride and potassium cyanide (Reissert-Henze reaction), corresponding 2-[3-(trifluoromethyl)phenyl]furo[3,2-c]pyridine-1-carbonitrile (VII) resulted. 5-Amino-2-[3-(trifluoromethyl)phenyl]furo[3,2-c]pyridin-5-ium-4-methylbenzene sulfonate (VIII) was prepared by direct N-amination of the title compound V with 1-[(aminooxy)sulfonyl]-4-methylbenzene in dichloromethane. Then, VIII was transformed to a non-isolated zwitterionic N-imid IX which afforded the corresponding furo[3,2-c]pyrazolo[1,5-a]pyridine carboxylic acid esters X, XI by 1,3-dipolar cycloaddition reactions with dimethyl but-2-ynedionate (DBD) or ethyl propiolate. The structures of all compounds were confirmed by their IR and NMR spectra. Presented at the 1st International Conference “Applied Natural Sciences” on the occasion of 10th anniversary of the University of St. Cyril and Methodius, Trnava, 7–9 November 2007.