New synthesis of condensed heterocycles from isoxazole derivatives VI. 2,5-Dimethyl-3-aeetyl-7-amino-1H-pyrrolo[3,2-b] pyridine

A new synthesis of pyrrolo[3,2-b] pyridine starting with pyrrole ring is described. The procedure allows the synthesis of 4-azaindoles bearing a sensitive group at C-7. The nitration of 4b with nitric acid and acetic anhydride at ?15° gave 5 . The hydrogenation of 5 led to simultaneous reduction of N-hydroxy and nitro groups and to hydrogenolysis of the isoxazole nucleus, affording an appropriate chain of atoms to building up the pyrrolo[3,2-b] pyridine ring.     

Cation complexing of crown ethers using fluorescence spectroscopy, part II

The complex formations of benzo[12]crown-4, benzo[15]crown-5 and benzo[18]crown-6 with perchlorate salts of Mg(2+), Li(+) and Na(+) were investigated using the steady state fluorescence emission spectroscopy in acetonitrile. The complexation enhanced quenched fluorescence spectra, (CEQFS) exhibited the ion complexation role of the macrocyclic ethers and equilibrium constant, K(e) of 1:1 stoichiometry were estimated. The K(e) were found in the order of Mg(+)>Na(+)>Li(+) for benzo[15]crown-5 whilst Na(+)>Mg(+)>Li(+) order was found with benzo[12]crown-4 at 298 K.     

Crown ethers as ancillary ligands in the assembly of silver(i) aggregates containing embedded acetylenediide

Five silver(I) double salts containing embedded acetylenediide, [Ag([12]crown-4)(2)][Ag(10)(C(2))(CF(3)CO(2))(9)([12]crown-4)(2)(H(2)O)(3)] x H(2)O (2), [Ag(2)C(2) x 5 AgCF(3)CO(2) x (benzo[15]crown-5) x 2 H(2)O] x 0.5 H(2)O (3), [Ag(4)([18]crown-6)(4)(H(2)O)(3)][Ag(18)(C(2))(3)(CF(3)CO(2))(16)(H(2)O)(2.5)] x 2.5 H(2)O (4), [Ag(2)C(2) x 6 AgC(2)F(5)CO(2) x 2([15]crown-5)](2) (5), and [(Ag(2)C(2))(2) x (AgC(2)F(5)CO(2))(9) x ([18]crown-6)(2) x (H(2)O)(3.5)] x H(2)O (6), have been isolated by varying the types of crown ethers and anions employed. Single-crystal X-ray analysis has shown that complex 2 is composed of winding anionic chains with sandwiched [Ag([12]crown-4)(2)](+) ions accommodated in the concave cavities between them. In 3, silver(I) double cages each sandwiched by a couple of benzo[15]crown-5 ligands are linked by [Ag(2)(CF(3)CO(2))(2)] bridges to form a one-dimensional structure. For 4, an anionic silver column is generated through fusion of two kinds of silver polyhedra (triangulated dodecahedron and bicapped trigonal antiprism), and the charge balance is provided by aqua-ligated [Ag([18]crown-6)](+) ions. Complex 5 is a centrosymmetric hexadecanuclear supermolecule composed of two [(eta(5)-[15]crown-5)(2)(C(2)@Ag(7))(mu-C(2)F(5)CO(2))(5)] moieties connected through a [Ag(2)(C(2)F(5)CO(2))(2)] bridge. Compound 6 is a discrete supermolecule containing an asymmetric (C(2))(2)@Ag(13) cluster core capped by two [18]crown-6 ligands in mu(3)-eta(5) and mu(4)-eta(6) ligation modes.     

6-氯-2(1 H)-喹喔酮合成方法的改进

设计了以对氯苯胺和氯乙酰氯为原料,经缩合、硝化、还原、环合、氧化五步制得6-氯-2(1H)-喹喔酮的位置选择性合成方法,并对以氯乙酰氯作为苯胺的氨基保护试剂进行硝化的反应和对含活泼氯的硝基化合物进行还原的反应进行了研究.研究结果表明以氯乙酰氯作为苯胺的氨基保护试剂进行硝化的反应符合一般的硝化定位规则,而含活泼氯的硝基化合物的还原在优化条件下以铁粉为还原剂可以高选择性获得目标产物.     

Alkaline Earth Metal Template (Cross-)Coupling Reactions with Hybrid Disila-Crown Ether Analogues

Alkaline earth metal iodides were used as templates for the synthesis of novel silicon-based ligands. Siloxane moieties were (cross-)coupled and ion-specific, silicon-rich crown ether analogues were obtained. The reaction of 1,2,7,8-tetrasila[12]crown-4 ( I ) and 1,2-disila[9]crown-3 ( II ) with MgI₂ yielded exclusively [Mg(1,2,7,8-tetrasila[12]crown-4)I₂] ( 1 ). The larger Ca²⁺ ion was then employed for cross-coupling of I and II and yielded the complex [Ca(1,2,7,8-tetrasila[15]crown-5)I₂] ( 2 ). Cross-coupling of I and 1,2,4,5-tetrasila[9]crown-3 ( III ) with SrI₂ enables the synthesis of the silicon-dominant 1,2,4,5,10,11-hexasila[15]crown-5 ether complex of SrI₂ ( 3 ). Further, the compounds [Sr(1,2,10,11-tetrasila[18]crown-6)I₂] ( 4 ), [Sr(1,2,13,14-tetrasila[24]crown-8)I₂] ( 5 ), and [Sr(1,2,13,14-tetrasila-dibenzo[24]crown-8)I₂] ( 6 ) were obtained by coupling I , 1,2-disila[12]crown-4 ( IV ) or 1,2-disila-benzo[12]crown-4 ( V ), respectively. Using various anions, the (cross-)coupled ligands were also observed in an X-ray structure within the mentioned complexes. These template-assisted (cross-)couplings of various ligands are the first of their kind and a novel method to obtain macrocycles and/or their metal complexes to be established. Further, the Si−O bond activations presented herein might be of importance for silane or even organic functionalization.     

The Synthesis of Novel Crown Ethers, Part VII [1]. Coumarin Derivatives of Benzocrowns and Cation Binding from Fluorescence Spectra

4-[3-(1-benzopyran-2-one)] derivativesof benzo[12]crown-4, benzo[15]crown-5 andbenzo-[18]crown-6 were synthesized from4-[3-(1-benzopyran-2-one)]-1,2-dihydroxy-benzenereacting with bis-ethyleneglycol dihalides orpentaethylene glycol ditosylate in alkali carbonate/DMF/water. The original products were identified byhigh resolution EI-mass spectra as well as IR,¹H-NMR and ¹³C-NMR spectroscopy. The 1 : 1binding constants of Mg²⁺, Li⁺, Na⁺ andK⁺ with the coumarin-benzocrowns were estimated usingfluorescence emission spectroscopy in acetonitrile.The complexing enhanced quenching fluorescence spectra(CEQFS) and complexing enhanced fluorescence spectra(CEFS) exhibited the ion binding powers due tocationic recognition rules of the macrocycles.     

Thiacalix[4]arene derivatives as radium ionophores: a study on the requirements for Ra2+ extraction

The synthesis and NOE-based structural characterization is described of thiacalix[4]arene tricarboxylic acid (7), thiacalix[4]crown-5 and -6 monocarboxylic acids (2 and 5), and the bis(N-methylsulfonyl)thiacalix[4]crowns-5 and -6 (4a,b). The 226Ra2+ selectivity coefficients, log(K(Ra)ex/K(M)ex), of the new thiacalix[4]arene derivatives are compared directly with those of thiacalix[4]crown-5 and -6 (1a,b), thiacalix[4]crown-5 and -6 dicarboxylic acids (3a,b), and thiacalix[4]arene di- and tetracarboxylic acids (6 and 8). Thiacalix[4]arene dicarboxylic acid (6) already exhibits a high 226Ra2+ selectivity, but this is significantly improved in the case of 3b, having an additional crown-(6-)ether bridge. The covalent combination of a crown ether and carboxylic acid substituents as in the thiacalix[4]arenes 2,3a,b,4a,b, and 5 gives a better 226Ra2+ selectivity in the presence of Sr2+ or Ba2+ than mixtures of dibenzo-21-crown-7 and thiacalix[4]arene dicarboxylic acid (6) or of pentadecanoic acid and thiacalix[4]crown-6 (1b).     

15]crown-5: an unsymmetrical bifacial hydrogen-bond acceptor in crystal engineering

Reaction of [15]crown-5 with erbium nitrate and a range of nickel salts results in the formation of the hydrogen-bonded chain species [Er(NO3)3(H2O)3]. [15]crown-5 H2O (3), [Ni(H2O)6]Br2 [15]crown-5 2H2O (4), [Ni(H2O)6](ClO4)2 x [15]crown-5 2H2O (5), [Ni(H2O)6](NO3)2 [15]crown-5 2H2O (6) and [[Ni(H2O)4]2(muCl)2]Cl2 [15]crown-5 (7). Complexes 3-5 exhibit low symmetry structures with 2-4 unique crown ether molecules, whereas 6 and 7 are more symmetrical. The factors contributing to this behaviour are discussed within the wider context of [15]crown-5 structures in the Cambridge Structural Database.     

Nitration of benzo[g]isoquinoline and its methyl-substituted derivatives

Di- and trinitro derivatives are formed in the nitration under mild conditions (0–5 °C) of benzo[g]isoquinoline and its analogs with a methyl substituent in the pyridine and phenylene rings. The principal reaction products contain a nitro group in the meso position (attached to the C₅ atom) and in the phenylene ring. The structures of the nitro derivatives obtained and the position of the nitro groups in the molecules were proved by means of the PMR, IR, and mass spectra.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1658–1661, December, 1981.     

Synthesis of new 4-quinolone-type compounds in the benzo[b]thiophene series

Some new derivatives of 1,4-dihydro-4-oxo-3-pyridinecarboxylic acid (quinolone-type compounds) 5 and 13 have been prepared in the benzo[b]thiophene series. The key step was the construction of the pyridine ring starting from 2-aminobenzo[b]thiophene derivatives. The synthesis of amine 9 , was performed by using an original “animation” reaction.     

Diversity‐oriented One‐pot Synthesis of Novel Imidazo[4′,5′:4,5]benzo[e][1,4]thiazepinones and Benzo[d]imidazolyl Thiazolidinones through pTSA Promoted Cyclization and Evaluation of Antimicrobial and Anti‐inflammatory Activities

In contrast to target‐oriented synthesis that aims to access precise regions of chemistry, diversity‐oriented synthesis via multicomponent synthesis populates chemical space broadly with small molecules having diverse structures. This study has achieved the diversity‐oriented synthesis of novel imidazo[4′,5′:4,5]benzo[e][1,4]thiazepinones ( 4 ) and benzo[d]imidazolyl thiazolidinones ( 5 ) controlled by the nature of substitution effect of the reaction component. The one‐pot reaction of benzimidazole 1 , aromatic aldehyde 2 , and mercaptoacetic acid 3 leads to the formation of imidazo[4′,5′:4,5]benzo[e][1,4]thiazepinones ( 4 ) with electron‐donating groups as substitution on aromatic aldehyde while electron‐withdrawing substitutions produced benzo[d]imidazolyl thiazolidinones ( 5 ). The title compounds ( 4 ) and ( 5 ) were evaluated for their antimicrobial and anti‐inflammatory activities.     

Synthesis of a New Library of Pyrano‐phenazine Derivatives via a Novel Three‐Component Protocol

The pyrano‐phenazine derivatives 6 were synthesized by an efficient procedure using the reaction between benzo[a]phenacin‐5‐ols with the condensation product of an aldehyde with Meldrum's acid in the presence of a catalytic amount of Et₃N at ambient temperature. The procedure is very simple, and products could be separated from the reaction media by simple filtration. High functional‐group tolerance both in the benzo[a]phenazin‐5‐ol and aldehyde moieties, facile reaction procedure, medium‐to‐high yields, and simple separation of the products from the reaction media are the advantages of this route.     

4'-(丹磺酰氨基)苯并冠醚和4'-[α-(丹磺酰氨基)乙基]苯并-15-冠-5的合成

从B12C4, B15C5和B18C6经过硝化、催化氢化和丹磺酰化合成了三种4'-(丹磺酰氨基)苯并冠醚, 从B15C5径乙酰化, Leuckart反应和丹磺酰化合成了另一个4'-[α-(丹磺酰氨)乙基]苯并-15-冠-5这些丹磺酰氨衍生物均为新荧光冠醚.     

Synthesis of Pyridophenanthrolines via a Three‐Component Reaction Involving 1,10‐Phenanthrolin‐5‐Amine

A facile and efficient method for the synthesis of benzo[b ]pyrido[3,2‐f ][1,7]phenanthrolines and dipyrido[4,3‐b :3′,2′‐f ][1,7]phenanthrolines has been developed in high yields. Using EtOH as a solvent without any additionally basic catalysts, the three‐component reaction of aromatic aldehyde, 1,10‐phenanthrolin‐5‐amine, and dimedone or piperidine‐2,4‐dione affords two novel classes of fused phentacyclic heterocycles containing both pyridine and phenanthroline moieties.     

Eu(fod)(3) binding on the (1)H-NMR spectra of some benzo[3n]crown-n and dibenzo[3n+2]crown-n

The complexing of Eu(fod)₃ with macrocyclic ethers, benzo[15]crown-5, benzo[12]crown-4, dibenzo[20]crown-6, dibenzo[23]crown-7 and dibenzo[26]crown-8 was observed on their ¹H-NMR spectra and the selective binding constants at 400 MHz and 305 K in CDCl₃ were reported. The Eu(fod)₃ interaction displayed the selective binding role of oxygen on macrocyclic, H₂COCH₂, backbones with o- or m-dioxyphenyl groups referring the ¹H chemical shifts. The estimated equilibrium constants, K_a of 1:1 ratio of interactions were in accordance with the Eu³⁺ ionic radii to bind the oxygen sites depending on the macrocyclic size and conformation of the ethers. The minimum lanthanide-macrocyclic ether distance displayed the maximum stability so that benzo[3n]crown-n (n=4, 5) group was found to bind the Eu(fod)₃ moderately whilst dibenzo[3n+2]crown-n (n=6-8) oligomer chemical shifts were induced largely since the such Eu³⁺ complexes are more stable with larger ethyleneoxy groups.     

Supramolecular cation assemblies of hydrogen-bonded (NH4+/NH2NH3+)(crown ether) in [Ni(dmit)2]-based molecular conductors and magnets

Hydrogen-bonded supramolecular cation assemblies of (NH4+/NH2-NH3+)(crown ether), where the crown ether is [12]crown-4, [15]crown-5, or [18]crown-6, were incorporated into electrically conducting [Ni(dmit)2] salts (dmit2- = 2-thioxo-1,3-dithiole-4,5-dithiolate). (NH4+)([12]crown-4)[Ni(dmit)2]3(CH3CN)2 had a pyramidal shape, while ionic channels were observed in (NH4+)(0.88)([15]crown-5)[Ni(dmit)(2)]2 and (NH4+)(0.70)([18]crown-6)[Ni(dmit)(2)]2. Both (NH4+)(0.88)([15]crown-5) and (NH4+)(0.70)([18]crown-6) contained regularly spaced [Ni(dmit)(2)] stacks formed by N-H.O hydrogen bonding between the oxygen atoms in crown ethers and the NH4+ ion. NH4+ occurred nonstoichiometrically; there were vacant ionic sites in the ionic channels. The ionic radius of NH4+ is larger than the cavity radius of [15]crown-5 and [18]crown-6. Therefore, NH4+ ions could not pass through the cavity and were distributed randomly in the ionic channels. The static disorder caused the conduction electrons to be randomly localized to the [Ni(dmit)2] stacks. Hydrazinium (NH2-NH3+) formed the supramolecular cations in (NH2-NH3+)([12]crown-4)2[Ni(dmit)2]4 and (NH2-NH3+)2([15]crown-5)3[Ni(dmit)2]6, possessing a sandwich and club-sandwich structure, respectively. To the best of our knowledge, these represent the first hydrazinium-crown ether assemblies to be identified in the solid. In the supramolecular cations, hydrogen bonding was detected between the ammonium or the amino protons of NH2-NH3+ and the oxygen atoms of crown ethers. The sandwich-type cations coexisted with the [Ni(dmit)2] dimer stacks. Although the assemblies were typically semiconducting, ferromagnetic interaction (Weiss temperature = +1 K) was detected in the case of (NH2-NH3+)2([15]crown-5)3[Ni(dmit)2]6. The (NH2-NH3+)0.8([18]crown-6)[Ni(dmit)2]2 and (NH4+)0.76([18]crown-6)[Ni(dmit)2]2 crystals were isomorphous. The large and flexible [18]crown-6 allowed for maintaining the same ionic channel structure through replacement of the NH4+ cation by NH2-NH3+.     

Synthesis and nitration of some thieno-fused analogues of the benzo[a]quinolizinium cation

Three thieno-fused analogues of benzo[a]quinolizinium ( 1 ), thieno[3,2-a]- and thieno[2,3-a]quinolizinium 4 and 5 and thiazolo[2,3-a]isoquinolinium ( 6 ), were synthesized by photocyclization of 1-(2-thienylvinyl)pyridinium salts 9a and 9b and 3-styrylthiazolium salt 9c , respectively. The nitration of the compounds 4, 5 , and 6 occurred predominantly at positions 2, 3, and 7, respectively, while the nitro group was introduced into the 8- and 10-positions of 1 in the ratio of 68:32. The nmr and uv spectral properties and reduction potentials of 4–6 were also compared with those of the parent compound 1 .     

An unexpected route toward the synthesis of spiro-benzo[b]acridine-furan derivatives

A facile and straightforward procedure for the synthesis of spiro-benzo[b]acridine-6,2′-furan derivatives via the reaction between benzo[b]acridine-6,11-dione, electron-deficient acetylenic compounds, and an isocyanide is described. The benzo[b]acridine-6,11-dione is obtained from the reaction between 2-(aminomethyl)aniline and 2-hydroxynaphthalene-1,4-dione via an unexpected reaction pathway. The products are synthesized in medium to high yields and no complicated purification is required.     

Synthesis of 5-Substituted 1,3-Dimethylpyrazolo[4,3-e][1,2,4]triazines

A novel method for the synthesis of a new series of 5-substituted 1,3-dimethyl pyrazolo[4,3-e][1,2,4]triazines is described. The new synthetic strategy is based on the classical Bischler 1,2,4-benzotriazine synthesis. This approach involves the preparation of 5-hydrazinopyrazole from 5-chloro-1,3-dimethyl-4-nitropyrazole followed by acylation and nitro group reduction to form the corresponding 4-amino-3-(acylhydrazino)pyrazoles. Intramolecular oxidative cyclization of the latter derivatives, using polyphosphoric acid, produced the respective target pyrazolotriazines.     

Synthesis of N-substituted benzo[c][1,7]- and benzo[c][1,8] phenanthrolin-(5H)-6-ones through a Pd-mediated Suzuki-Miyaura heteroaryl-aryl coupling reaction

In the course of the search for non-camptothecin topoisomerase I inhibitors we have undertaken the synthesis of N-substituted benzo[c][1,7]- and benzo[c][1,8]phenanthrolinone derivatives. An intermolecular Suzuki-Miyaura heteroaryl-aryl coupling reaction was planned as the key step. Then a nitro reduction followed by a concomitant lactamization achieved the construction of the tetracycle structures. This methodology permitted a rapid and efficient elaboration of biologically potent compounds.