Synthesis and structures of isomeric benzobisthiazoles

It is shown that the bases described in a number of papers and patents as 2,6-dimethyl-, 2,6-diamino-, and 2,6-dimercaptobenzo[1,2-d:4,3-d']bisthiazoles (isomers of linear structure) are actually 2,7-dimethyl-, 2,7-diamino-, and 2,7-dimercaptobenzo [1,2-d:6,5-d']bisthiazoles (isomers of angular structure). The synthesis of the hitherto unknown 2,6-dimethylbenzo[1,2-d:4,5-d'] bisthiazoles is described.     

2,6-二取代苯并二噁唑的合成方法研究

文献报道合成2,6-二芳基取代苯并[1,2-d;4,5-d']二(口恶)唑有两种方法,其一是2,5-二氨基对苯醌与芳香醛缩合,然后氧化,关环;其二是2,5-二氨基对苯二酚盐酸盐与酰氯缩合关环.     

Benzo[1,2-d: 3,4-d'] diimidazole derivatives

The structure and tautomerism of 2-amino-3, 6-dimethyl-, and 2-amino-3,6,7-trimethylbenzo[1,2-d: 3,4-d']diimidazoles were studied by means of IR and UV spectroscopy. It was found that they exist in the amino form in the crystalline state and in methanol solution.See [1] for communication III.Translated from Khimiya GeterotsiklicheskikhSoedinenii, No. 6, pp. 807–809, June, 1973     

Application of bis(iminophosphorane) in heterocyclic synthesis: new entries to symmetrically or unsymmetrically substituted thieno[2,3-d:5,4-d']dipyrimidine-4,5(3H,6H)-diones

The bis(carbodiimides) 4, obtained from bis-aza-Wittig reactions of bis(iminophosphorane) 3 with 2 equiv of aromatic isocyanates, were reacted with secondary amine to give symmetrically substituted 2,7-diaminothieno[2,3-d:5,4-d']dipyrimidine-4,5(3H,6H)-dione 6 in the presence of a catalytic amount of EtO(-)Na(+). Reactions of 4 with phenols or ROH in the presence of a catalytic amount of potassium carbonate or RO(-)Na(+) gave symmetrically substituted 2,7-diaryl(alkyl)oxythieno[2,3-d:5,4-d']dipyrimidine-4,5(3H,6H)-diones 6 in satisfactory yields. However, iminophosphoranes 9 were obtained via reaction of bis(iminophosphorane) 3 with 1 equiv of aromatic isocyanate and subsequent reaction with an amine in the presence of a catalytic amount of EtO(-)Na(+). Further reaction of iminophosphoranes 9 with aromatic isocyanates and various nucleophile generated unsymmetrically substituted thieno[2,3-d:5,4-d']dipyrimidine-4,5(3H,6H)-diones 12 in good yields.     

Benzo[1,2-d:3,4-d′]diimidazole derivatives

A new path for the synthesis of 3-monoalkyl- and 3,6-dialkyl-substituted benzo[1,2-d:3,4-d']-diimidazole is described: 5-tosylamino-1-alkylbenzimidazole is converted to the 4-nitro derivative by nitration in glacial acetic acid, and the imidazole ring is closed after alkylation and cleavage of the tosyl group.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1406–1409, October, 1970.     

The photochemistry of a bis-crown ether based on benzobis(thiazole) and its alkaline earth metal cation complexes

Irradiation of acetonitrile solutions of the bis-crown ether E,E-2,7-bis[2-(6,7,9,10,12,13,15,16-octahydro-5,8,11,14,17-pentaoxabenzocyclopentadecen-2-yl)vinyl]-benzo[1,2-d;3,4-d']bisthiazole (hereafter, 1) gives efficient E --> Z photoisomerization (initial phi(trans --> cis) = 0.48), leading to lambda(exc)-dependent quasi-photostationary states composed primarily of E,Z and E,E isomer mixtures. Further irradiation gives [2 + 2]-cycloadducts of 1. In the presence of Ba2+ ions, essentially quantitative formation of 2:2 complexes, 1(2) x (Ba2+)2 controls the photochemical outcome. E --> Z photoisomerization of the ligand is entirely suppressed and efficient intramolecular [2 + 2]-photocycloaddition in the complexes leads to cyclobutane dimers of 1 (phiCB = 0.26). The reactivity of 1 in the presence of Mg2+ ions for which 1:2 complex formation dominates gives both cis-trans photoisomerization and enhanced photocycloaddition.     

Structural determination of two new triterpenoid saponins acylated with monoterpenic acid from Gymnocladus chinensis Baill

Two new triterpenoid saponins acylated with monoterpenic acid, 2β,23-dihydroxy-3-O-α-L-rhamnopyranosyl-21-O-{(6S)-2-trans-2,6-dimethyl-6-O-[3-O-(β-D-glucopyranosyl)-4-O-(2-methylbutanoyl)-β-L-arabinopyranosyl]-2,7-octadienoyl)-acacic acid 28-O-β-D-xylopyranosyl-(1?→?3)-β-D-xylopyranosyl-(1?→?4)-[β-D-glucopyranosyl-(1?→?3)]-α-L-rhamnopyranosyl-(1?→?2)-[α-L-rhamnopyranosyl-(1?→?6)]-β-D-glucopyranosyl ester and 2β,23-dihydroxy-3-O-α-L-rhamnopyranosyl-21-O-{(6S)-2-trans-2,6-dimethyl-6-O-[4-O-((6S)-2-trans-2,6-dimethyl-6-O-(β-L-arabinopyranosyl)-2,7-octadienoyl)]-β-L-arabinopyranosyl]-2,7-octadienoyl}-acacic acid 28-O-β-D-xylopyranosyl-(1?→?3)-β-D-xylopyranosyl-(1?→?4)-[β-D-glucopyranosyl-(1?→?3)]-α-L-rhamnopyranosyl-(1?→?2)-[α-L-rhamnopyranosyl-(1?→?6)]-β-D-glucopyranosyl ester were isolated from the fruit of Gymnocladus chinensis Baill. and the structural elucidation of both the compounds was accomplished by extensive studies of their spectroscopic (1D and 2D NMR, TOF-MS, QFT-MS) and chemical methods.     

溶致性液晶高分子PBT的结构表征

聚苯撑苯并二噻唑(PBT)具有典型的溶致性液晶行为,聚合后期有液晶态搅拌乳光现象。偏光显微镜观察到具有向列型织态结构,溶液粘度随浓度变化,当进入液晶区时有明显的反常突变。对高分子链和凝聚态结构进行了X射线衍射研究,测定了晶胞参数、C轴等同周期和高分子链的取向度,并表明取向的PBT凝聚态是由刚性棒状的分子呈园柱体形态二维有序堆砌而成的。     

2,6-二（对氨基苯）苯并[1,2-d;5,4-d']二噁唑的合成和纯化

1,2,3-三氯苯经过硝化、水解、催化加氢、缩合等四步反应，合成了2,6-二（ 对氨基苯）苯并[1,2-d;5,4-d']二噁唑，总产率为70%。同时，研究了一种有效的? 亟峋?,6-二（对氨基苯）苯并[1,2-d;5,4-d']二噁唑的方法。与其他方法相比， 该法原料便宜易得，产物可作为聚合反应的单体原料。     

两个非对映异构三萜皂甙的结构鉴定

从合欢皮95%乙醇提取物中分得2个新三糖链九糖皂甙(1,2),经化学方法和光谱分析,将其结构分别鉴定为:3-O-[β-D-吡喃木糖基-(1→2)-β-D-吡喃阿拉伯糖基-(1→6)-β-D-葡萄糖基]-21-O-(6S)-2-反式-2,6-二甲基-6-O-[4-O-((6R)-2-反式-2,6-二甲基-6-O-β-D-吡喃鸡纳糖基-2,7-辛二烯酸基)-β-D-吡喃鸡纳糖基]-2,7-辛二烯酸基金合欢酸28-O-β-D-吡喃葡萄糖基-(1→3)-[α-L-呋喃阿拉伯糖基-(1→4)]-α-L-吡喃鼠李糖基-(1→2)-β-D-吡喃葡萄糖基酯(1)和3-O-[β-D-吡喃阿拉伯糖基-(1→2)-β-D-吡喃呋糖基-(1→6)-β-D-葡萄糖基]-21-O-(6S)-2-反式-2,6-二甲基-6-O-[4-O-((6S)-2-反式-2,6-二甲基-6-O-β-D-吡喃鸡纳糖基-2,7-辛二烯酸基)-β-D-吡喃鸡纳糖基]-2,7-辛二烯酸基金合欢酸28-O-β-D-吡喃葡萄糖基-(1→3)-[α-L-呋喃阿拉伯糖基-(1→4)]-α-L-吡喃鼠李糖基-(1→2)-β-D-吡喃葡萄糖基酯(2),分别命名为合欢皂甙J₁₄(JulibrosideJ₁₄)和合欢皂甙J₁₅(JulibrosideJ₁₅)     

Synthesis and multitopic complex formation of a photochromic bis(crown ether) based on benzobis(thiazole)

2,7-Bis[2-(6,7,9,10,12,13,15,16-octahydro-5,8,11,14,17-pentaoxabenzocyclopentadecen-2-yl)vinyl]-benzo[1,2-d;3,4-d']bisthiazole, 2, with crown ether styryl moieties substituted on a heterocyclic core, was synthesized and its complex forming ability with several metal cations was evaluated in acetonitrile by absorption and fluorescence spectroscopy. The results are compared to those for the analogous ligand possessing a single crown ether styryl moiety. Selective binding of the metal cation at the heterocyclic core of both ligands was observed only for Hg2+. Alkali and alkaline earth cations bind selectively at the crown ether moieties. Stability constants and pure spectra of defined stoichiometry were determined with the use of HYPERQUAD, a least-squares fitting program, and the results were validated in one case by subjecting the titration spectral matrix to singular value decomposition with self-modeling (SVD-SM). The multitopic ligand 2 forms relatively strong 2:2 stoichiometric complexes with K+, among the alkali metal cations, and Ba2+, among the alkaline earth metal cations, and is a promising selective optical sensor for these ions.     

Square-planar N2S2NiII complexes with an extended pi-conjugated system

The reaction of a mixture of 2-(1-naphthyl)benzothiazoline (HL1) and 2,6-diphenylbenzo[1,2-d:4,5-d']bisthiazoline (H3L2) with nickel(II) acetate tetrahydrate yielded three kinds of square-planar nickel(II) complexes: one nickel(II) complex with innocent ligands ([Ni(L1)2] (1c)) and two nickel(II) complexes with non-innocent ligands ([Ni(L1-L1)] (1a) and [Ni(L1-L2)] (1b)). The complex 1c has two bidentate-N,S ligands, which are formed via ring opening of HL1. On the other hand, the two complexes 1a and 1b contain a tetradentate-N2S2 ligand, which is created via ring opening of HL1 and H3L2, followed by bond formation between imino carbon atoms. Complexes 1a and 1b show very intense absorptions in the near-infrared (NIR) region, characteristic of square-planar complexes with non-innocent ligands. The third nickel(II) complex having a non-innocent tetradentate-N2S2 ligand ([Ni(L2-L2)] (2)) was prepared from H3L2 and nickel(II) acetate tetrahydrate. The electronic spectrum of 2 exhibits a very intense absorption at 981 nm (epsilon = 3.6 x 10(4) M-1 cm-1), which is significantly red-shifted compared with those of 1a (837 nm and 4.4 x 10(4) M-1 cm-1) and 1b (885 nm and 4.5 x 10(4) M-1 cm-1), indicating the presence of an extended pi delocalization. The reaction of 2,6-bis(3,5-dichlorophenyl)benzo[1,2-d:4,5-d']bisthiazoline (H3L3) with nickel(II) acetate tetrahydrate also led to the formation of a nickel(II) complex with a non-innocent ligand ([Ni(L3-L3)] (3)). While complex 3 is analogous to 2, its electrical conductivity is much higher than that of 2. The molecular structures of 1b, 1c, 2, and 3 were determined by X-ray crystallography.     

One-pot synthesis of 4,8-dibromobenzo[1,2-d;4,5-d']bistriazole and synthesis of its derivatives as new units for conjugated materials

The one-pot synthesis of 4,8-dibromobenzo[1,2-d;4,5-d']bistriazole, followed by alkylation and Stille coupling to yield three different isomeric derivatives with markedly different optoelectronic properties, is reported. These derivatives show potential as new units in organic oligomers and polymers for electronics applications.     

Synthesis of 5H-benzimidazo[1,2-a][1,3,4]thiadiazolo[2,3-d][1,3,5]triazin-5-one and 12H-benzimidazo[1,2-a]pyrimido[6,1-d][1,3,5]triazin-12-one,two new heterocyclic ring systems

2-(2,6-Dimethylpyrimidin-4-ylaminobenzimidazole) (VIIa) and 2-(1,3,4-thiadiazol-2-ylamino)benzimidazole (VIIb) underwent a ring-closure reaction with phosgene giving 1,3-dimethyl-12H-benzirnidazo[1,2-a]pyrirnido[6,1][-d][1,3,5]triazin-12-one (IIa) and 5H-benzimidazo[1,2-a][1,3,4]thiadiazolo[2,3-d][1,3,5]triazin-5-one (IIb) two hitherto unknown heterocyclic systems. A convenient synthesis of 2,6-dimethyl-4-aminopyrimidine is described.     

化合物[2,6-bis(benzo[1,2-d:4,5-d′]diimidazole-2′-yl)pyridine] 的合成、晶体结构和光物理性质

A new tridentate benzimidazole derivative, 2,6-bis (benzo[1,2-d:4,5-d′]diimidazole-2′-yl) -pyridine (Bzdiimpy),was prepared from o-phenylenediamine in five steps with improved methods according to the literature in good yield.The crystal structure was determined by X-ray diffraction analysis. It crystallized in monoclinic, space group P21/c,with a=1.1708(4) nm, b=2.4796(9) nm, c=1.215 9(4) nm,β=114.641(7)°, Z=1, R=0.035 0, wR2=0.0890. The bzdiimp molecule displayed an almost planar structure and formed a zig-zag chain through weak interactions between imidazole-N and [SnCl6]2--Cl. Its electronic absorption and emission spectra were measured and compared with the reported analogue 2,6-bis (benz[1,2-d:4,5-d′]imidazole-2′-yl)-pyridine (Bzp).     

Bridgehead nitrogen heterocycles. VI. The reaction of 1-amino- and 1,2-diaminopyridinium salts with β-dicarbonyl compounds

1,2-Diaminopyridinium iodide underwent reaction with ethyl acetoacetate to form 1,4-dihydro-2-methyl-4-oxopyrido[1,2-a]pyrimidin-1-ium iodide, and with acetyl acetone it gave 2,4-dimethylpyrido[1,2-a]pyrimidin-5-ium iodide. Though 2-acetylcyclohexanone gave the corresponding 5-methyl-1,2,3,4-tetrahydropyrido[1,2-a]quinazolin-11-ium iodide, no reaction was observed with 2,6-dimethyl-3,5-heptanedione, 1-benzoylacetone, 1,3-diphenyl-1,3-propanedione and its p-methoxyphenyl derivative. However, 1-aminopyridinium iodide and acetyl acetone in the presence of base gave 3-acetyl-2-methylpyrazolo[1,5-a]pyridine and 1-amino-2-methylpyridinium iodide yielded the corresponding 3-acetyl-2,7-dimethylpyrazolo[1,5-a]pyridine. With ethyl acetoacetate, the latter salt formed 3-ethoxycarbonyl-2,7-dimethylpyrazolo[1,5-a]pyridine but with 2,6-dimethyl substituents in the pyridine ring no condensation occurred. Reaction of 1-amino-2-methylpyridinium iodide with benzaldehyde gave N-benzalimino-2-methylpyridinium iodide which, on treatment with base, resulted in the formation of 2-picoline and benzonitrile, providing a convenient method of deamination.     

Synthesis of benzo[1,2-d;3,4-d']diimidazole and 1H-pyrazolo[4,3-b]pyridine as putative A2A receptor antagonists

The synthesis and the binding affinity for the putative adenosine receptor antagonist 6-methyl-7-[1,2,3]triazol-2-yl-1,6-dihydrobenzo[1,2-d;3,4-d']diimidazole (10) and 5-oxazol-2-yl-1H-pyrazolo[4,3-b]pyridin-3-ylamine (16) are reported. The title compounds were prepared from commercially available 1-chloro-2,4-dinitrobenzene (1) and 2-chloro-6-methoxy-3nitropyridine (11), respectively, but proved devoid of affinity for the adenosine A1 and A2A receptors.     

Anatolioside E: A New Acyclic Monoterpene Glycoside from Viburnum orientale

A new open-chain monoterpene glycoside, anatolioside E ( 1 ), was isolated from the leaves of Viburnum orientale in addition to three known acyclic monoterpene glycosides, betulalbusides A ( 2 ) and B ( 3 ), and 2(E)-2,6-dimethyl-2,7-octadien-1,6-diol-6-O-β-D -glucopyranoside( 4 ). The structure of anatolioside E ( 1 ) was elucidated on the basis of chemical and spectral data as 6-O-[β-D -glucopyransoyl-(1?? → 6?″)-2-(E), 6(R), 2,6-dimethyl-6-hydroxy-2,7-octadienoyl-(1?″ → 2″″)-β-D -glucopyranosyl-(1″″ → 6?)-2-(E), 6(R), 2,6-dimethyl-6-hydroxy-2,7-octadienoyl-(1? → 4″)-α-L -rhamnopyranosyl-(1″″ → 2′)-β-D -glucopyranosyl]linalool.     

Formation of substituted 6-hydroxy-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridine upon photochemical transformation of nifedipine

Long-term exposure of nifedipine to daylight in ethanol gives 2,2"-bis[3,5-bis(methoxycarbonyl)-2,6-dimethylpyridin-4-yl]azoxybenzene and 6-hydroxy-1-methoxycarbonyl-2,4-dimethyl-5-oxo-5,6-dihydrobenzo[c][2,7]naphthyridine as the major products.     

Kondensationen mit hydrazin-N,N′-dicarbonsäure-diamidin—XVII : 4,5-dialkylderivate des 2,7-diamino-imidazo[5,1-f]-as-triazins

In interactions of β-dicarbonyl compounds (2) with azodicarboxamidine (1), the primary reaction step consists of the addition of the active methylene group in 2 to the NN double bond in 1. Via the addition product 3 thus formed, 2,7-diamino-4,5-dialkyl-imidazo[5,1-f]-as-triazines (4) are produced through condensation. 3,5-Heptanedione (2a), 4,6-nonanedione (2b), and 2,6-dimethyl-3,5- heptanedione (2c) have been used as β-dicarbonyl compounds.