Synthesis of 2-Acyl- and 2-Sulfonylbenzisoselenazol-3(2H)-ones

Synthesis of two new groups of organoselenium compounds: 2-acyl-and sulfonylbenzisoselenazol-3(2H)-ones (3, 4), potential immunostimulants, in two alternative ways was elaborated. One of them was based on the reaction of 2-chlorobenzoyl chloride (2) with primary amides while the second one involved N-acylation or N-sulfonylation of benzisoselenazol-3(2H)-one (5) with acid chlorides. Two exceptions from general reaction of dichloride 2 with amides were observed. Thioacetamide produced 2,1-benzothiaselenophenone (6), and urea gave 6,7-benzo-2,4-diaza-1-selenacyclohepta-3,5-dione (7).     

新型手性N,N′-双支套索冠醚的合成及其应用

(S)-苯丙氨醇和原氯乙酸三乙酯作用得到的手性酰胺醇和手性噁唑啉分别与1,7-二氮-12-冠-4反应, 得到了两种手性N,N′-双支套索冠醚N,N′-二[(S)-N-(1-羟甲基-2-苯基乙基)乙酰胺-2]-1,7-二氮-12-冠-4 (1a)和N,N′-二[(S)-4-苄基-噁唑啉-2-亚甲基]-1,7-二氮-12-冠-4 (1b). 前者应用于D/L-肉碱的手性分离; 后者的铜配合物用于重氮醋酸酯对烯烃的不对称环丙烷化反应.     

p-tert-Butylcalix[4]arene Derivatives Containing Azathiol Receptors and Their Recognition towards Hg(II)

25,27(2,2'-bis(ethoxybenzyl))-1,9-diimine-3,7-dithianonane-p-tert-butylcalix[4]arene (3),25,27(4,4'-bis(ethoxybenzyl))-1,9-diimine-3,7-dithianonane-p-tert-butylcalix[4]arene (4),25,27(2,2'-bis(ethoxybenzyl))-1,8-diimine-3,6-dithianonane-p-tert-butylcalix[4]arene (5) and25,27(4,4'-bis(ethoxybenzyl))-1,8-diimine-3,6-dithianonane-p-tert-butylcalix[4]arene (6) havebeen synthesized by condensation reactions between25,27(2,2'-bis(ethoxybenzaldehyde))-p-tert-butylcalix[4]arene (1) and25,27(4,4'-bis(ethoxybenzaldehyde))-p-tert-butylcalix[4]arene (2) and appropriateamines. Reduction of 3 and 4 withNaBH₄ and subsequent protonation byHCl/CH₃OH resulted in25,27(2,2'-bis(ethoxybenzyl))-1,9-diaza-3,7-dithianonane-p-tert-butylcalix[4]arenedihydrogenchloride (7) and25,27(4,4'-bis(ethoxybenzyl))-1,9-diaza-3,7-dithianonane-p-tert-butylcalix[4]arenedihydrogenchloride (8), respectively. Complexation studies of 7 and 8 withZn(II), Cd(II) and Hg(II) ions were carried out bypotentiometric titration. Compounds 7 and8 selectively form 1 : 1 complexes with Hg(II), andtheir stability constants (log Ks) were estimated tobe 4.47 ± 0.08 and 3.20 ± 0.13, respectively. From spiecies distribution plots, 7 and 8were found to form the highest amount of 1 : 1 complexes with Hg(II) at pH 8.7 and 9.1, respectively.     

Synthesis, structures, and properties of 3,6-di-tert-butyl-o-benzosemiquinone complexes of copper(i) with 1,5-diaza-3,7-diphosphacyclooctanes

Two new 3,6-di-tert-butyl-o-benzosemiquinone complexes of copper(i) (2a and2b) with 1,3,5,7-tetraphenyl-1,5-diaza-3,5-diphosphacyclooctane (1a) and 1,5-dibenzyl-3,7-diphenyl-1,5-diaza-3,7-diphosphacyclooctane (1b), respectively, were synthesized. Their structures in solution and in the crystalline state were studied. According to the results of X-ray diffraction analysis, the copper(i) atom in molecules2a and2b is in a pseudotetrahedral environment and is directly coordinated to two P atoms of the diazadiphosphacyclooctane ligand and two O atoms of the benzosemiquinone ligand. In complex2a, ligand1a adopts a chair-boat conformation typical of all complexes with eight-membered cyclic 1,5-donors studied previously. Unlike ligand1a, the ligand in complex2b adopts a chair-chair (crown) conformation identical with that of the free ligand. Both complexes are paramagnetic in the solid state and in solutions. The parameters of the isotropic ESR spectra of complexes2a and2b are typical of four-coordinateo-semiquinone copper(i) complexes with bidentate bisphosphine ligands. Based on analysis of the isotropic ESR spectra, it was suggested that compound2b in solutions exists as two isomers, which differ in the conformation of the eight-membered heterocycle (chair-boat or chair-chair). Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1806–1812, October, 2000.     

Synthesis,crystal structure,and fluorescence properties of several schiff-base compounds

Two new Schiff-base compounds, 1,6-bis(4-dimethylaminobenzyl)-2,5-diaza-1,5-hexadiene (bdh), 1,4-bis(4-dimethylaminobenzyl)-2,3-diaza-1,3-butadiene (bdb), and a silver complex of the latter ([Ag₂(bdb)₃(NO₃)₂]·H₂O, 1) have been synthesized and characterized. The crystal structure of complex 1 was determined. 1 is a dinuclear complex, with the silver ions lying in coordination tetrahedra formed by two nitrogen atoms from the bdb ligands and two oxygen atoms from the nitrate anions. The fluorescence properties of bdh and bdb were studied; the fluorescence of bdb was quenched by the addition of silver ions, indicating that it is a potential fluorescent reagent for the analysis of silver.     

Synthesis and characterization of three new thermally stable N-heterocyclic germylenes

Three new stable germylenes, rac-1,3-di-tert-butyl-4,5-dimethyl-1,3-diaza-2-germacyclopentane-2-ylide (1), 1,3-di-tert-butyl-4,4-dimethyl-1,3-diaza-2-germacyclopentane-2-ylide (2), and rac-1,3,4-tri-tert-butyl-1,3-diaza-2-germacyclopentane-2-ylide (3) have been synthesized by the reaction of their corresponding germyl dichlorides with elemental lithium. Full synthetic procedures and characterizations are described.     

Syntheses and characterization of different zinc(II) oxide nano-structures from direct thermal decomposition of 1D coordination polymers

Three zinc(II) nitrite coordination polymers, [Zn(4-bpdb)(NO₂)₂]_n (1), {[Zn(3-bpdb)(NO₂)]·0.5H₂O}_n (2) and [Zn(3-bpdh)(NO₂)₂]_n (3), 4-bpdb = 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene, 3-bpdb = 1,4-bis(3-pyridyl)-2,3-diaza-1,3-butadiene and 3-bpdh = 2,5-bis(3-pyridyl)-3,4-diaza-2,4-hexadiene} were prepared and characterized by elemental analyses and IR spectroscopy. Compound 3 was structurally characterized by single-crystal X-ray diffraction and is one-dimensional polymer with coordination environments of distorted octahedral, ZnN₂O₄. The thermal stabilities of compounds 1–3 were studied by thermal gravimetric (TG) and differential thermal analyses (DTA). Direct calcination of the compounds 1–3 at 600 °C under air atmospheres yields different morphologies of nano-sized ZnO.     

Secoiridoids and other chemotaxonomically relevant compounds in Pedicularis: phytochemical analysis and comparison of Pedicularis rostratocapitata Crantz and Pedicularis verticillata L. from Dolomites

We compared the respective metabolite patterns of two Pedicularis species from Dolomites. Seven phenylethanoid glycosides, i.e., verbascoside (1), echinacoside (2), angoroside A (3), cistantubuloside B1 (4), wiedemannioside C (5), campneoside II (11) and cistantubuloside C1 (12), together with several iridoid glucosides as aucubin (6), euphroside (7), monomelittoside (8), mussaenosidic acid (9) and 8-epiloganic acid (13) were identified. Pedicularis verticillata showed also the presence of greatly unexpected secoiridoids, ligustroside (14) and excelside B (15), very rare compounds in Lamiales. Both PhGs and iridoids are considered of taxonomical relevance in the Asteridae and their occurrence in Pedicularis was discussed. In particular, the exclusive presence of several compounds such as 8-epiloganic acid (13), campneoside II (11), cistantubuloside C1 (12), ligustroside (14) and excelside B (15) in Pedicularis rostratocapitata, and angoroside A (3), cistantubuloside B1 (4) and wiedemannioside C (5) in P. verticillata could be considered specific markers for the two botanical entities.     

Hetero-Diels-Alder reaction of some 1,3-diaza-1,3-butadienes with ketenes. Synthesis of functionalized pyrimido[1,2-b]-benzothiazoles and 1,3,4-thiadiazolo-[3,2-a]pyrimidines

Summary Reaction of 1,3-diaza-1,3-butadienes (1a–c) with various ketenes and chloroketenes results in the formation of substituted 4-oxo-pyrimido[2,1-b]benzothiazoles (4a–d) and 1,3,4-thiadiazolo[3,2-a]pyrimido-4-ones (4e,f). Reaction of 1,3-diaza-1,3-butadienes1d,e with ketenes and chloroketenes leads to the 2-morpholine-substituted compounds7 and15, respectively. All reactions proceedvia formation of [4+2] cycloadducts that eliminate methylthiol, methylsulfenyl chloride, or morpholine.

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Hetero-Diels-Alder-Reaktion einiger 1,3-Diaza-1,3-butadiene mit Ketenen. Synthese funktionalisierter Pyrimido[1,2-b]benzothiazole und 1,3,4-Thiadiazolo[3,2-a]pyrimidine

Zusammenfassung Die Reaktion der 1,3-Diaza-1,3-butadiene1a–c mit verschiedenen Ketenen und Chlorketenen führt zu substituierten 4-Oxo-pyrimido[2,1-b]benzothiazolen (4a–d) und 1,3,4-Thiadiazolo[3,2-a]pyrimido-4-onen(4e,f). Die 1,3-Diaza-1,3-butadiene1d,e ergeben mit Ketenen und Chlorketenen die 2-Morpholin-substituierten Verbindungen7 und15. Alle Reaktionen verlaufen über [4+2]-Cycloaddukte, die Methylthiol, Methylsulfenylchlorid oder Morpholin eliminieren.

     

UV-stability and UV-protective activity of alkaloids from the marine sponge Zyzzya fuliginosa

Alkaloids from the marine sponge Zyzzya fuliginosa damirones A (1) and B (2); makaluvamines H (3), C (4), G (5), and L (6); and zyzzyanones A (8) and B (9) were investigated for the ability to protect egg-cell membranes of the sea urchin Strongylocentrotus nudus from UV-radiation. Damirones, zyzzyanones, and tricyclic makaluvamines C (4) and H (3) exhibited the greatest membrane-protective activity. It was shown that makaluvamines G (5) and L (6) were converted by UV-irradiation into damirones A (1), B (2), tricyclic makaluvamines H (3), C (4), and zyzzyanones A (8) and B (9), respectively. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 62–64, January–February, 2006.     

Über 4,4,6-trisubstituierte 3,4-Dihydro-2(1H)-pyrimidinimine,Hexahydro-2(1H)-chinazolinimine bzw.-one bzw.-thione und Spiro[cycloalkan-1,4′(1′H)-cycloalkeno-pyrimidin]-2′ (3′H)-imine

The 2-alken-1-ones2 b, 2 c and3–8, which have very different structures, were reacted with guanidine to give cyclic compounds:2 b and2 c resp. are transformed by guanidine to the trisubstituted 3,4-dihydro-2(1H)-pyrimidinimines1 b and1 c resp., action of guanidine on the cyclo-hexylidenaceton (3) yields 4-methyl-1,3-diaza-4-spiro[5,5]-undecen-2-imine (11); isopropylidencyclohexanone4 and the isomeric (methylcyclohexenyl)ethanone5 condense with guanidine resp. urea resp. NH₄CNS to give 4,4-dimethyl-3,4,5,6,7,8-hexahydro-2(1H)-quinazolinimine (15), resp.-one (16), resp.-thione (17) and 4,8a-dimethyl-3,4,6,7,8,8a-hexahydro-2(1H)-quinazolinthione (19). With the cycloalkyliden-alkanones6–8 guanidine reacts to yield the spiro[cycloalkan-1,4(1H)-cycloalkenopyrimidin]-2(3H)-imines24–26. The structure of the compounds cited is derived from their NMR-and (partially) mass spectra; from most of the bases picrates were also synthesized.

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Herrn Prof. Dr.H. Grubitsch zum 70. Geburtstag gewidmet.     

Titanium-dioxide-mediated photocatalysed reaction of selected organic systems

The photocatalysed reaction of four selected organic systems, namely dichlone (1), 2-amino-5-chloropyridine (2), benzoyl peroxide (3) and 3-chloro perbenzoic acid (4), has been investigated in an acetonitrile/water mixture in the presence of titanium dioxide and oxygen. An attempt has been made to identify the products formed during the photo-oxidation process using the GC/MS analysis technique. The photolysis of dichlone (1) leads to the formation of phthalic anhydride (11) and 1H-indene-1,2,3-trione (10), whereas 2-amino-5-chloropyridine (2) gave rise to 2,2′-diamino bipyridyl (14), 2-pyridinamine (16), 2-hydroxy-5-chloropyridine (18), bipyridyl (19) and 2-amino bipyridyl (21). The photolysis of benzoyl peroxide (3) yielded a mixture of products such as benzoic acid (24), biphenyl (27), biphenyl-4-carboxylic acid (29) and benzoic acid phenyl ester (30). Two intermediate products, as 3-chlorobenzaldehyde (35) and hydroxyl added 3-chlorobenzaldehyde (33), have been identified in the case of 3-chloro perbenzoic acid (4). The products have been identified by comparing the molecular ion and mass fragmentation peaks of the products with those reported in the GC-MS library. A probable mechanism for the formation of the products has been proposed.     

Sonochemical syntheses and characterization of new nanorod crystals of mercury(II) metal–organic polymer generated from polyimine ligands

Nanorod crystals of two new mercury(II) [Hg(II)] coordination polymers, [Hg(4-bpdh)Br₂] _n (1) and [Hg(3-bpdh)Br₂] _n (2) {4-bpdh = 2,5-bis(4-pyridyl)-3,4-diaza-2,4-hexadiene and 3-bpdh = 2,5-bis(3-pyridyl)-3,4-diaza-2,4-hexadiene}, were prepared from the reaction of Hg(II) bromide with 4-bpdh and 3-bpdh by a sonochemical method. The nanorod crystals of 1 and 2 were characterized by scanning electron microscopy, X-ray powder diffraction, and IR spectroscopy. Compounds 1 and 2 were structurally characterized by single-crystal X-ray diffraction. The thermal stabilities of 1 and 2 were studied by thermal gravimetric and differential thermal analyses, which revealed that nanostructures of 1 and 2 are somewhat less stable than their bulk materials.     

Synthesis of Some Selenacrown Ethers and the Thermodynamic Origin of Their Complexation with C60

Two new selenacrown ethers, i.e., N,N′-dimethyl-1,11-diaza-4,8,14,18,-tetraselenacycloicosane (1) and 7,11-diseleno-2,3,15,16,-dibenzo-1,4,14,17,20,23-hexaoxacyclopentacosane (2), have been synthesized and characterized by elemental analysis and UV, and ¹H-NMR spectroscopy. An X-ray crystallographic structure was obtained for 1. UV-spectrophotometric titrations have been performed in CCl₄ solution at 25–50 °C to obtain the complex stability constants (K_s) and the thermodynamic parameters (ΔH⁰ and TΔS⁰) for the stoichiometric 1:1 complexation of [60]-fullerene (C60) with the crown ethers 1–4. The obtained K_s values together with that reported for dicyclohexano-24-crown-8 (5) reveal that, the more the heteroatom numbers in crown ether ring are, and the larger the cavity sizes of crown ethers are, the higher theK_svalues for complexation with C60 are. Thermodynamically, the complexation of C60 with 1–5 is absolutely enthalpy-driven in CCl₄, while the complex stability is governed by the entropy term.     

Chemical constituents from the flowers of Satsuma mandarin and their free radical scavenging and α-glucosidase inhibitory activities

Flowers of Citrus plants are used as mild sedatives and for the treatment of insomnia in traditional medicines. In Japan, tea made from the flowers of Satsuma mandarin is consumed as healthy drink. Hesperidin (1), hesperetin (2), rutin (3), quercetin (4), nicotiflorin (5), eriocitrin (6), narirutin (7), phenylethyl glucoside (8) and unshuoside A (9) were isolated from the MeOH extract of fresh flowers. Structure elucidation of these compounds was performed on the basis of NMR spectroscopic data. Among them, rutin (3), quercetin (4) and eriocitrin (6) showed potent free radical scavenging activity, whereas hesperetin (2) and quercetin (4) showed potent α-glucosidase inhibitory activity.     

Reaktionen vonN-Sulfinylverbindungen mit dem 1,2,4-Trithia-3,5-diborolan-Ringsystem und Substitutionsreaktionen am 1,2,4-Trithia-3,5-diborolan und 1,2-Dithia-4-aza-3,5-diborolidin

The reaction of trimethylsilyl- and pentafluorophenyl-N-sulfinylamine respectively with 3,5-dihalogeno-1,2,4-trithia-3,5-diborolanes yields the 1,2-dithia-4-aza-3,5-diborolidines1-3.Tert-butyl-N-sulfinylamine and 3,5-dimethyl-1,2,4-trithia-3,5-diborolane react analogous. OtherN-sulfinylamines however split the disulfane bridge in 3,5-dimethyl-1,2,4-trithia-3,5-diborolane and the 1,4-dithia-2-aza-3,5-diborolidines5A-7(A) are formed. Besides of boroxines, cyclo-2,4,6-trimethyl-1,3-dioxa-5-aza-2,4,6-triboranes and cyclo-2,4,6-trimethyl-1-oxa-3,5-diaza-2,4,6-triboranes are formed as byproducts,8–10 have been isolated. In 1,2,4-trithia-3,5-diborolanes and 1,2-dithia-4-aza-3,5-diborolidines the bromo-atoms can be substituted by alkyl (13, 14), by amino (15–20) and by isothiocyanato groups. The compounds were characterised analytically and spectroscopically (MS; NMR:¹H,¹¹B,¹⁹F,²⁹Si; IR).

     

Novel Synthesis of a Macromonomer Having Organosilyl and Amino Groups

Abstract

Reaction between dimethyldivinylsilane (1) and N,N′-diethyl-N-lithio-ethylenediamine (2a) in the presence of N,N′-diethylethylenediamine (3a) in THF at 20°C gave a monoadduct, 3,3-dimethyl-6-ethyl-3-sila-6,9-diaza-1-undecene (4a). An anionic self-polyaddition reaction of 4a in the presence of lithium diisopropylamide (LDA) proceeded to form oligomers. Each of the oligomers thus obtained was found to carry a polymerizable vinylsilane moiety at the oligomer chain terminal. As a result, a new type of macromonomer having alternating repeating units of ethylenediamine and organosilyl groups was synthesized. Acid-base titration showed the macromonomer to have unique characteristics on protonation of diamine moieties. Anionic polyaddition reactions between 1 and N-lithio-piperazine (2b) in the presence of piperazine (3b) also gave a macromonomer consisting of alternating repeating units of piperazine and organosilyl groups (4b). Radical copolymerizations of styrene with 5b gave comblike graft copolymers.     

Anti-steatosis compounds from leaves of Mallotus furetianus

There is no drug administration-approved therapy for non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH). In this study, eight compounds, gallic acid (1), methyl gallate (2), corilagin (3), 3,4,8,9,10-pentahydroxydibenzo[b,d]pyran-6-one (4), repandinin B (5), (Z)-3-hexenyl-β-D-glucopyranoside (6), (+)-lyoniresinol-3α-O-α-L-rhamnopyranoside (7) and mallophenol A (8) were isolated from the active fractions of Mallotus furetianus. Three compounds, (6, 7 and 8) revealed potent anti-steatosis activity in the oleic acid (OA)-induced steatosis cell model, with the minimum effective concentration of 0.05 (6), 0.0005 (7) and 0.0005 (8) μg/mL, which were much lower than the control compound, fibrate (72.4 μg/mL).     

Rubescins I and J,further limonoid derivatives from the stem bark of Trichilia rubescens (Meliaceae)

Two new tetranorterpenoid derivatives named rubescins I (1) and J (2), were isolated along with six known compounds including rubescin D (3), lichexanthone (4), scopoletin (5), scopoletin O-glycoside (6), β-sitosterol (7) and stigmasterol (8) from the stem bark of Trichilia rubescens (Meliaceae). The structures of the compounds were determined by means of MS, different NMR and by comparison with related data reported in the literature.     

Two new linear acetogenins from the fruits of Goniothalamus gracilipes

Two new linear acetogenins, gracilipin A (1) and methylsaccopetrin A (2) along with seven known compounds, saccopetrin A (3), 7,3′,4′-trimethylquercetin (4), rhamnazin (5), casticin (6), isokanugin (7), melisimplexin (8) and 5-hydroxy-3,7-dimethoxy-3′,4′-methylenedioxyflavone (9) were isolated from the fruits of Goniothalamus gracilipes Bân. Their structures were established by spectral analysis, such as mass spectrometry, 1D-NMR, 2D-NMR and circular dichroism (CD). Compounds 1 and 3 showed cytotoxic activity against KB cell line with IC₅₀ values of 14.6 and 15.3 μM, respectively.