Chloro Compounds Research Articles

Thermal, structural and electrical studies of the chloro complexes of cobalt, nickel and copper with 2-butoxypyridine

The chloro compounds of 2-butoxypyridine with cobalt, nickel and copper were prepared in ethanolic solution from which solid compounds were isolated. The suggested structure for the cobalt compound is tetrahedral, whereas for the nickel and copper compounds it is octahedral. The techniques of thermogravimetry and differential thermal analysis show that the copper compound forms an intermediate compound before the metal oxide is formed. The cobalt and nickel compounds decompose with loss of the organic ligand and chlorine to give the metal oxides. Room temperature electrical conductivities of the prepared compounds show near-ohmic behaviour and are in the narrow range of 2.41 × 10 −8 to 6.33 × 10 −8 Ω −1 m −1. The temperature dependence of conductivity shows anomalous behaviour. The similarity in electrical properties of the compounds studied suggests that the conductivities are intrinsically controlled.

Thermal, structural and electrical studies of the chloro complexes of cobalt, nickel and copper with 7,8-benzoquinoline

The chloro compounds of 7,8-benzoquinoline with cobalt, nickel and copper were prepared in ethanolic solution from which solid compounds were isolated. The suggested structure for the cobalt compound is tetrahedral, whereas for the nickel and copper compounds it is polymeric octahedral. The techniques of thermogravimetry and differential thermal analysis show that the cobalt compound forms an intermediate compound before the metal oxide is formed. The nickel and copper compounds decompose with loss of organic ligand and chlorine to give the metal oxides. Electrical conductivities for the compounds at room temperature lie in the narrow range 3.09 × 10 −8 Ω −1 m −1 (for the copper compound) to 3.59 × 10 −7 Ω −1 m −1 (for the cobalt compound). The current-voltage characteristic for the uncomplexed 7,8-benzoquinoline is ohmic, but its complexes exhibit hysteresis. The temperature dependences of conductivity have been determined for the compounds and are used to measure the activation energies for conduction.

SYNTHESIS OF SOME THIAZOLO[5,4-D] PYRIMIDINES

Abstract 4-Amino-3-phenyl-2-thioxothiazol-5-carboxamide (1) reacts with aromatic aldehydes to form thiazolo-pyrimidines (2a,b ), and with acetic anhydride to thiazolopyrimidine (2C ). Thiazolocarboxamides (1a,b ) were converted to thiazolotriazines (3a,b ) by reaction with nitrous acid. When thiazolopyrimidine (2C ) was refluxed with POCl3, the corresponding chlorothiazolopyrimidine (4) was isolated. The produced chloro compound (4) can be converted into the corresponding thiazolopyrimidindithiones (5) or substituted aminothiazolopyrimidines (6,7), when allowed to react either with thiourea, aromatic amine or hydrazine hydrate. S-alkylated thiazolopyrimidines (8a-k ) were produced when compound (5) was reacted with halo compounds or acrylonitrile. Hydrazino compound (7) reacts with acetylacetone to produce the pyrazolylthiazolopyrimidine (9).

Preparation, structural characterisation, thermal and electrical studies of the chloro complexes of cobalt, nickel and copper with acrylamide

The chloro compounds of cobalt, nickel and copper with acrylamide have been prepared. Spectral and magnetic data have been used to deduce the stereochemistry of the compounds. The thermal behaviour of acrylamide and its complexes with cobalt, nickel and copper have been studied by thermogravimetry and differential thermal analysis. The cobalt complex forms an intermediate complex before the metal oxide is produced. The nickel and copper complexes undergo decomposition with loss of the organic ligand and chlorine to give the metal oxides. Electrical conductivities for the compounds at room-temperature are in the range 5.8 × 10 −8 Ω −1 m −1 (for the cobalt compound) to 3.1 × 10 −5 Ω −1 m −1 (for the copper compound). The current-voltage characteristic for the uncomplexed acrylamide is ohmic whereas its complexes exhibit hysteresis which is attributed to orientation of the polar complexed molecules in the applied electric field. The temperature dependences of conductivity have been determined for the compounds and are used to measure the activation energies for conduction.

Functionalized Chloroenamines in Aminocyclopropane Synthesis ‐ VII. A Diastereocomplementary Approach to Amino‐Bicyclo[n.1.0]Alkanenitriles on the Basis of Chlorinated Enamines

AbstractReductive dechlorination of amino‐chlorobicycloalkanenitriles 5a‐c was achieved by sodium in tert.butyl alkohol/THF to give the bicyclic nitriles 6a‐c. LiAIH4 as dechlorination reagent caused a ring opening reaction with 5b,c producing diamines 7b,c. The bicyclic chloro compounds 5b,c could by obtained from enamines 1 via dichloroenamines 4. Monochlorination of 1b,c and subsequent cyclopropanation with cyanide yielded endo‐bicycloalkanenitriles 3b.c. Compounds 3 and 6 thus generally can be synthesized in a diastereocomplementary way starting from enamines 1.

Synthesis, structure and vibrational spectra of a new uranium(IV) complex: UCl(H 2PO 2) 3·2H 2O

The preparation, crystal structure and vibrational spectra of the new uranium (IV) compound UCl(H 2PO 2) 3·2H 2O are reported. The uranium atom is surrounded by six hypophosphito and two aqua oxygen atoms at the corners of a square antiprism. Hypophosphite groups serve as bridges between uranium atoms in the polymeric structure. The bands in the IR spectrum which correspond to hypophosphite modes of vibration are very similar to those of the isostructural bromo analogue UBr(H 2PO 2) 3·2H 2O, whereas features involving aqua ligand modes show stronger halide—water hydrogen bonding for the chloro compound.

Chlorine-containing compounds produced during Dictyostelium development. Detection by labelling with 36Cl

DIF-1 [Differentiation-Inducing Factor 1; 1-(3,5-dichloro-2,6-dihydroxy-4-methoxyphenyl)hexan-1-one] is a novel chlorinated signal molecule that induces stalk-cell differentiation during development of Dictyostelium discoideum. Here we introduce the use of the radioisotope 36Cl to label DIF-1 and other low-Mr chlorinated compounds produced during development. H.p.l.c. and t.l.c. were used to resolve the labelled compounds. We find the following. (1) At least 14 dialysable 36Cl-labelled compounds are released into the medium by cells labelled continuously through development with Na36Cl. (2) The compounds can be classified into two major groups according to their times of accumulation in development. The early group of compounds starts accumulating at the end of aggregation, co-ordinately with DIF-1; the late group is only made at the end of development, by mature fruiting bodies. There may also be an intermediate group made during culmination. (3) The early group of compounds has been identified as comprising DIF-1 and seven of its metabolites by co-chromatography with the authentic compounds. These metabolites had previously only been recognized in suspensions of living cells incubated with exogenous DIF-1. Their detection here, from cells undergoing normal development, suggests that endogenous DIF-1 is metabolized in normal development in much the same way as is DIF-1 added to cells in suspension. (4) The intermediate and late groups of compounds are not obvious DIF-1 metabolites. They may have some role unconnected with DIF signalling. (5) A group of 36Cl-labelled late compounds remain cell-associated after washing of the fruiting bodies, and these are greatly enriched in stalk, compared with spore, cells. (6) Other slime-mould species were labelled with 36Cl. All three tested, namely D. mucoroides, D. vinaceo-fuscum and P. violaceum, also produced chloro compounds. D. mucoroides produced DIF-1 by the criterion of h.p.l.c. co-elution with authentic DIF-1. A developmentally regulated metabolism of chlorinated compounds may therefore be widespread amongst slime moulds. To our knowledge, labelling with 36Cl in vivo has not been reported before and provides a powerful general method for investigating chlorinated compounds in diverse organisms.

Pulse radiolysis studies on the polymerization of 1,6-hexanediol diacrylate in cyclohexane solvent

The mechanism of initiation and kinetics of radiation induced polymerization of 1,6-hexanediol diacrylate (HDDA) was studied by pulse radiolysis with optical detection in cyclohexane solution and in pure HDDA at room temperature. In both cases a transient light absorption decreasing with the wavelength in the 270–400 nm wavelength range, but possessing a shoulder at 310 nm was observed. The spectrum did not change with time after the pulse. The absorption is due to α-carboxyalkyl radicals: the assignment was supported by the results obtained from the reaction of electrons with methyl 2-chloropropionate leading to dechlorination. The radicals produced from HDDA or from the chloro compound decayed in a second order process with rate parameters of 5 · 10 8 and of 4 · 10 9 mol -1 dm 3 s -1 in cyclohexane. In the presence of oxygen the corresponding peroxy radicals decaying in very slow process (several milliseconds) were observed. The results are interrupted in terms of radical polymerization mechanism.

Preparation of novel low-coordinate chloro and azido phosphorus-nitrogen compounds. Attempted synthesis of cyclodiphosphazenes

Preparation of novel low-coordinate chloro and azido phosphorus-nitrogen compounds. Attempted synthesis of cyclodiphosphazenes

Activity of acyclic halogenated tubercidin analogs against human cytomegalovirus and in uninfected cells

Novel acyclic halogenated tubercidins (4-amino-5-halo-7-[(2-hydroxyethoxy)-methyl]pyrrolo[2,3- d]pyrimidines) were examined for their ability to inhibit human cytomegalovirus (HCMV) in yield reduction assays. 5-Bromo acyclic tubercidin (compound 102) was a more potent inhibitor of virus replication than the chloro- and iodo-substituted analogs (compounds 100 and 104). At a 100 μM concentration, the bromo and chloro compounds were more potent than acyclovir but not ganciclovir. Virus titers were reduced more than 99% by compounds 102 and 104 whereas compound 100 and the equally potent acyclovir reduced titers by only 90%. Quantitation of viral DNA by DNA hybridization demonstrated strong inhibition of HCMV DNA synthesis by these compounds. The most potent inhibitor, compound 102, had a 50% inhibitory (I 50) concentration (1.6 μM) comparable to that of ganciclovir (1.8 μM). Cytotoxicity in uninfected human cells was evaluated and revealed the following: cell growth rates slowed markedly in the presence of 10 μM compound 102 whereas the same concentration of compounds 100 and 104 led to only a slight prolongation of population doubling time; these compounds inhibited cellular DNA synthesis but not RNA or protein synthesis, as measured by incorporation of radiolabeled precursors into acid-precipitable macromolecules; flow cytometry indicated that compound 102 was a mid-S phase blocker, and adenosine antagonized the inhibition of [ 3H]dThd incorporation by compound 102. Together, these results demonstrate that compound 102 is a potent and selective inhibitor of viral and cellular DNA synthesis and that acyclic halogenated pyrrolopyrimidine nucleosides may have therapeutic potential.

The Electrochemical Nature of GaAs in Acids: A Comparison with InP

The chemical composition of surface oxides grown on was investigated using x‐ray diffraction techniques. Native oxides were prepared by exposing the to and etchants at concentrations ranging from pH 5 to the maximum acidities available. A mixture of crystalline stoichiometric phases were formed. The chemical oxides appear to be more complex than indicated by previous studies by x‐ray photoelectron spectroscopy, but were independent of the type of etchant or its acidity. Only constituent oxides, rather than mixed oxides, were found on the oxidized surface. The thermodynamics may play a key role in the reaction pathway. In the etch, GaI and GaI‐Ga III chloro compounds are not formed, and the dissolution of is severely inhibited even in the most acidic solutions under illumination. This complete absence of nucleophilic attack of the Ga‒As bond by a Cl− ion is reasonably well explained by the fact that the intermediate, , is not thermodynamically stable.

Influence of some steric and electronic effects on the mechanism of SNAr reactions in dimethyl sulphoxide

AbstractThe reactions of 1‐chloro‐ and 1‐fluoro‐2,4‐dinitrobenzenes with aniline and 4‐methylaniline in dimethyl sulphoxide are not base catalysed. When the nucleophile is 2‐methylaniline, the reaction of the fluoro compound is base catalysed whereas that of the chloro compound is not. The reactions of 1‐bromo‐2‐fluoro‐ and 1‐bromo‐2‐chloro‐3,5‐dinitrobenzenes with both aniline and 2‐methylaniline are not base catalysed. These results indicate that, in certain cases, the incidence or absence of base catalysis in aromatic nucleophilic substitution (SNAr) reactions in dipolar aprotic solvents results from an interplay of steric and electronic factors as they affect the magnitude of the (k2 + k3 [B])/k−1 ratio.

Thermal, spectral and magnetic studies of chloro complexes of cobalt, nickel and copper with 4-(butylamino) benzoic acid

The chloro compounds of 4-(butylamino) benzoic acid with cobalt, nickel and copper were prepared in an ethanolic solution from which solid compounds were isolated. The compounds were characterised with analyses, magnetic moments, vibrational and electronic spectra. The cobalt compound has a tetrahedral structure while the nickel and copper compounds have polymeric octahedral structures. The thermal behaviour of these compounds has been studied by thermogravimetry and differential thermal analysis. The cobalt compound, which is hydrated, loses water of crystallisation followed by loss of organic ligand and chlorine to give the metal oxide. The nickel and copper compounds lose organic ligand and chlorine to give the metal oxide.

Thermal, structural and electrical studies of the chloro and bromo complexes of cobalt, copper and zinc with 3-methyl-2-phenylpyridine

Abstract The chloro and bromo compounds of cobalt, copper and zinc with 3-methyl-3-phenyl-pyndine were prepared in ethanolic solution from which solid compounds were isolated. The suggested structure for the cobalt and zinc compounds is tetrahedral, while for the copper compounds it is tetragonal. The techniques of thermogravimetry and differential thermal analysis show that the compounds bis(3-methyl-2-phenylpyndine)cobalt(II) chloride and bis(3-methyl-2-phenylpyridine)zinc(II) chloride form intermediate compounds before their metal oxides are produced. The other compounds lose organic ligand followed by halogen to give the metal oxide Electrical conductivities at room temperature and for heating to 70°C were measured. The room temperature conductivity of the zinc complexes greatly exceeds (by a factor of about 10 4) that of the copper and cobalt complexes

Synthesis of 1-functionalized-6-hydroxy-4-methyl and 6,11-dihydroxy-4-methylnaphtho[2,3-g]isoquinoline-5,12-quinones

Using 2-methoxy- and 2,5-dimethoxyacetophenones 8a and 8b as starting materials, 1-chloro-4-methylisoquinoline-5,8-quinone (6) and its 6-bromo derivative 7 were obtained via multistep sequences. Whereas Diels-Alder condensation of the former compound with homophthalic anhydride (22) led to a mixture of the two possible isomers: 1-chloro-11-hydroxy-4-methylnaphtho[2,3-g]isoquinoline-5,12-quinone (23) and 1-chloro-6-hydroxy-4-methylnaphtho[2,3-g]isoquinoline-5,12-quinone (24), this last tetracyclic chloroquinone was specifically obtained from 6-bromo-1-chloro-4-methylisoquinoline-5,8-quinone (7) and homophthalic anhydride. The 6,11-dihydroxy derivative was then prepared by ammonium nitrate oxidation or photochemically by cycloaddition of benzocyclobutenedione (28) and 1-chloro-4-methylisoquinoline-5,8-quinone (6). Chloro compounds were easily substituted by diamines to provide corresponding 1-amino substituted hydroxy tetracyclic quinones.

Stereoselective reaction of an enolate with chiral .alpha.-halo boronic acid esters

Reaction of tert-butyl trans-lithiopropionate (6) with (S,S)-diisopropylethanediol («DIPED»)(1R)-(1-bromopentyl) boronate (9a) yielded semipurified tert-butyl (2S,3S)-3-hydroxy-2-methylheptanoate (11a) («threo») in a 60:1 ratio to the «erythro» diastereomer. Other threo/erythro ratios included DIPED (1R)-(1-bromo-2-methylpropyl) boronate (9b) to crude 11b, 15:1, DIPED (α-bromobenzyl) boronate (9c) to crude 11c, 8:1; (3S,4S)-2,5-dimethoxy-2,5-dimethyl-3,4-hexanediol (1R)-(1-bromo-pentyl) boronate (9d) to semipurified 11a, 10:1; and pinacol (1-bromopentyl) boronate (5) to semipurified racemic 11a, >100:1. These reactions are sluggish, and α-bromo boronic acid esters generally give better yields than the corresponding chloro compounds

Thermal, spectral and magnetic studies of the chloro complexes of cobalt(II), nickel(II) and copper(II) with phenetidine

The chloro compounds of p-phenetidine with cobalt(II), nickel(II) and copper(II) were prepared in ethanolic solution from which solid compounds were isolated. The suggested structure for the cobalt compound is tetrahedral, while for the nickel and copper it is octahedral. The techniques of thermogravimetry and differential thermal analysis show that the compounds dichloro-bis( p-phenetidine) cobalt(II) and dichloro-bis( p-phenetidine) nickel(II) form intermediate compounds before the metal oxide is produced. The compound dichloro-bis( p-phenetidine) copper(II) decomposes with loss of the phenetidine and chlorine and the formation of copper oxide.

ChemInform Abstract: Synthesis and Reactivity of Fluoro(organyl)phosphanes

Abstract A new method for producing fluoro(organyl) phosphanes is presented. They are prepared by Cl/F-exchange from the corresponding chloro compounds using Et3N.nHF as a fluorinating agent. Phosphanyl fluorophospharanes, R2P-PR2F2, are found to be intermediates of the disproportionation of Fluoro (diorganyl) phosphanes. R2PF react with aldehydes to form phosphinito phosphoranes, R2PF2-CHR'-OPR2. Oxaphospholenes are formed in their reaction with α, β- unsaturated aldehydes. Furthermore, the reactions with 1.2-diketones, carboxylic acid derivatives, and covalent azides are described.

Synthesis and antirhinovirus activity of cyano and amidino substituted flavanoids

Cyano and amidino flavans, isoflavans and 3(2H)-isoflavenes were synthesized in order to study their in vitro antirhino-virus activity, by comparison with the known corresponding chloro derivatives. The activity of the new compounds was evaluated on rhinovirus 1 B infected HeLa cell cultures by examining their ability to interfere with viral cytopathic effect and with plaque formation. It was found that generally the cyano derivatives behave like the chloro compounds, whereas the amidino derivatives show a lower activity, although always dependent on the position of substituent.

Thermal, spectral and magnetic studies on the chloro compounds of some first-row transition metals with triethylenediamine

Compounds of triethylenediamine with the chlorides of manganese, iron, cobalt, nickel and copper have been prepared in ethanolic solution. The compounds, which have been characterised by analyses, magnetic moments, and vibrational and electronic spectra, show that for the iron and cobalt compounds the metal ions are in a tetrahedral environment, whereas for the manganese, nickel and copper compounds the metal ions are in an octahedral environment. The thermal behaviour of these compounds has been studied by thermogravimetry and differential thermal analysis. The iron, cobalt, nickel and copper compounds which are hydrated lose water, followed by organic ligand and halogen, to give the metal oxide. The manganese compound loses the organic ligand and halogen to form an oxide of manganese.