Chlorine Atoms In Positions Research Articles

Synthesis and properties of analogs of 5(or 4)-aminoimidazole-4(or 5)-carboxamide (aica) and purines. 12. Investigation of the interaction of 4-chloroimidazo[4,5-d]-1,2,3-triazine with nucleophiles

The reactions of 4-chloroimidazo[4,5-d]-1,2,3-triazine with a number of nucleophilic reagents have been studied. Either replacement of the chlorine atom in position 4 of the 1,2,3-triazine ring or opening of the triazine ring with the formation of products of the interaction of the intermediate 5-diazoimidazole-4-carbonitrile with these nucleophiles occurs, depending on the nucleophilicity of the reagent.

Preparation and DNA-binding properties of substituted triostin antibiotics.

Novel derivatives of the triostin group of antibiotics were prepared by supplementing cultures of the producing organism Streptomyces triostinicus with a variety of aromatic carboxylic acids. Five new antibiotics, each having both the natural quinoxaline chromophores replaced by a substituted ring system, were purified to homogeneity and characterized by high-pressure liquid chromatography and nuclear magnetic resonance. Their antibacterial activities and DNA-binding properties were investigated. Addition of a halogen atom at position 6 of the quinoxaline ring or an amino group at position 3 had little effect on either the biological activity or the DNA-binding characteristics. The bis-3-amino derivative is fluorescent, and its fluorescence is strongly quenched by calf thymus DNA and polydeoxyguanylate-polydeoxycytidylate but not by polydeoxyadenylate-polydeoxythymidylate, suggesting that it binds preferentially to guanosine-cytosine-rich sequences in natural DNA. Binding constants for the bis-6-chloro and bis-3-amino derivatives do not differ greatly from those of unsubstituted triostin A. The analogs having two quinoline chromophores or a chlorine atom in position 7 of the quinoxaline ring display little or no detectable antibacterial activity, in marked contrast to the other congeners. Bis-7-chloro-triostin A binds conspicuously more tightly to polydeoxyadenylate-polydeoxythymidylate than to any other polynucleotide tested.

Inducibility of benzoate oxidizing cell activities in Acinetobacter calcoaceticus strain Bs 5 by chlorobenzoates as influenced by the position of chlorine atoms and the inducer concentration

Among four chlorobenzoates tested, only 3-chlorobenzoate and 4-chlorobenzoate were capable of inducing benzoate oxidizing cell activities in Acinetobactercalcoaceticus strain Bs 5, whereas 2-chlorobenzoate and 2,6-dichlorobenzoate were not. With the monochlorobenzoates, this inducing capability decreased with increasing proximity of the chlorine atom to the carboxyl group, i.e. in the order: 4-chlorobenzoate > 3-chlorobenzoate > 2-chlorobenzoate. It is therefore supposed that the induction of benzoate oxidizing cell activities is inhibited primarily be sterical influences of the chlorine substituents of the various chlorobenzoates.

THE CRYSTAL STRUCTURE OF P-CHLORO BENZOYL PIPERIDINE

The p-chloro benzoyl piperidine. C12H14 ONCL crystal belongs to the orthorhombic system. The space group is P21 21 21 with α=11.490(6)?, b = 10.462(5)?, c=9.928(5)?, z = 4 and calculated density Dc= 1.2410 gcm-3. The intensity data were collected on a Philips PW-1100 diffractometer. With the chlorineatom position found from Patterson method, the structure was determined by Fourier synthesis and refined by full-matrix least square method to a final R value of 0.093 for 697 reflexions. The hydrogen atom coordinate parameters were obtained from difference Fourier synthesis. The absolute configuration of molecule was determined by anomalous scattering method.

Studies on the vapor behavior of selected polychlorinated biphenyls.

The vapor loss of several PCB isomers from stainless steel planchets surfaces has been studied. Experiments were carried out under two different conditions. In one case, the vapor loss was observed from 2 molecular layers of PCB, while in the other series, the loss from approximately 200 molecular layers was observed. In both cases the loss of PCB from the surface was substantial, although the controlling mechanism of vapor loss was different. In the first case, the transport was approximated by a simple first order rate law, whereas in the latter case, it was a diffusion controlled process. In general, the vapor loss decreased with increasing number of chlorine atoms present in the isomer. The 4,4(1)-dichlorobiphenyl showed a deviation as compared to others indicating that such factors as the electronic distribution, position of chlorine atom on the biphenyl ring and symmentry of the molecule are also important in discussing the vapor transport.

Structure refinement of potassium chloroplatinate by powder and single-crystal methods

The crystal structure of potassium chloroptatinate, K2PtCI6, has been refined from both single-crystal and powder X-ray diffraction data. The system is cubic, space group Fm3m with a= 9.751 +_ 0.005 A. The measured density is 3-47 + 0-01 g cm -a and the calculated density for Z = 4 is 3.478 g cm -3. Interatomic distances are Pt-CI, 2.323 (1) A, CI-Cl, 3.285 (2) A (in the same octahedron), 3-610 (2) A (in adjacent octahedra) and K-CI, 3.449 (1) A. For the two determinations the values of the chlorine atom position parameter agree within one standard deviation and the temperature factors agree relatively; however, the powder method yielded temperature factors which were slightly larger. The results suggest that the powder method, when applied to high-symmetry systems with small numbers of variable parameters, yields refined parameters comparable in reliability to those from the single-crystal method.

On the “1–3” effect in conjugated systems

It was found that 2,3,4,5-tetrachloro-( trans-hexatriene, presents conformational isomerism by rotation about a single C-C bond, due to the steric requirements of the chlorine atoms in positions 2,4(3,5).

Effect of Chlorophenol Analogues on the Oxidative Phosphorylation in Rat Liver Mitochondria

The inhibition of chlorophenol analogues on oxidative phosphorylation in rat liver mitochondria was studied using polarographic technique and some new findings that not only pentachlorophenol (PCP) but also other analogues inhibited the oxidative phoshorylation in a similar manner were made. The inhibitory activity was found to be roughly correlated with its dissociation constant of the inhibitor, PCP being the strongest, varying with the number and position of chlorine atoms in the molecule. The mode of the inhibition was classified into three types and discussed in detail.

Effect of Chlorophenol Analogues on the Oxidative Phosphorylation in Rat Liver Mitochondria

The inhibition of chlorophenol analogues on oxidative phosphorylation in rat liver mitochondria was studied using polarographic technique and some new findings that not only pentachlorophenol (PCP) but also other analogues inhibited the oxidative phoshorylation in a similar manner were made. The inhibitory activity was found to be roughly correlated with its dissociation constant of the inhibitor, PCP being the strongest, varying with the number and position of chlorine atoms in the molecule. The mode of the inhibition was classified into three types and discussed in detail.

Chlorination of Guaiacol as a Model Compound of Benzene Nucleus of Lignin

To make clear the mechanism of chlorination of lignin by an aqueous solution, chlorination of lignin and model compounds has been investigated since some years ago.In advance of the investigaton of the complex lignin-like models, guaiacol was investigated firstly, because it would be thought to show the fundamental principle of the chlorination reaction of the benzene nucleus.Part 1.A homogeneous aqueous solution of guaiacol (128 gr guaiacol/7l water) was treated with 7.5l of aqueous chlorine solution (molar ratio 1 : 1) for about 1/2 hr . at 0°C, a small portion of sodium solution was added to destroy the excess of remaining chlorine or hypochlorous acid if any, pH adjusted to nine with sodium hydroxide, sodium borohydride added in order to avoid the polymerization of quinoidal structure if any, acidified, the resinous products separated (I), and the whole was extracted continuously with chloroform (II) followed by ether (III).I and II were distilled in vacuo into four fractions respectively, each fraction was examined gas chromatographically, and the fractions containing similar components were combined.From the five fractions thus obtained the following compounds were separated and identified.1) Guaiacol : as 3.5-dinitro-benzoate, m. p. 137°-139°C.2) 5-Cbloroguaiacol : as 3.5-clinitro-benzoate, rn. p.170°-171.5°C.3) 4.5-dichloroguaiacol : White needles, m. p. 71°-73°C.The melting points of these three compounds are not depressed on admixture with the authentic samples.4) Trichloroguaiacol : Pale yellow needles, m. p. 103°-106°C.The position of chlorine atoms are not settled as yet.5) 3-3′-Dimethoxy 4-4′-dihydroxydiphenyl : White prisms, melting at 166°-167°C. Diacetyl derivative, melting at 200.5°-202°C. Dimethyl derivative (biveratrol), melting at 132°-133°C.Melting points of the diphenyl and its two derivatives agree well with the values reported in literatures.The diphenyl has one phenolic hydroxyl group per methoxyl group, according to the so-called Δe-method of Aulin-Erdtman.From III the following compounds were separated and identified.1) Pyrocatechol : White prisms, melting at 103.5°-104.5°C.2) 3-Chloropyrocatechol : The compound was isolated as mono carboxymethyl ether, melting at 122-123.5°C. undepressed on admixture with the authentic sample of 3-chlorocatechol monocarboxy methyl ether.The position of the carboxymethyl group of the monoether is not determined. Diether was not prepared, as it was found to be difficult to etherify both hydroxyl groups of 3-chloropyrocatechol by an.usual method.Part 2.0.48, 1.09, 3.15 and 4.23 moles of chlorine were brought into reaction with one mol of guaiacol, just as in the case of part I. Excess chlorine was removed by allylalcohol, and the solution was extracted with ether without being preceeded by any reduction with sodium borohydride.Pyrocatechol and 3-chloropyrocatechol were identified in the extract by paper chromatography using benzene : acetic acid : water =1 : 1 : 2 as mobile phase, confirming the direct formation of pyrocatechol structure by the chlorination of guaicol.Results so far obtained on the effects of aqueous chlorine water on the guaiacol nucleus are summarized as follows : 1) Methoxyl group is demethylated to give methanol in high yield.2) Isolation of pyrocatechol suggests that demethylation can occur without introduction of any chlorine atoms into the nucleus.3) One to three chlorine atoms are introduced without cleavage of methoxyl groups.4) It seems therefore to be probable that chlorination of the nucleus and the demethylation of methoxyl group are independent reactions.5) Guaiacol dimerizes by dehydrogenation.

Synthesis and physiological properties of some heterocyclic‐aromatic sulphides and sulphones: II. Synthesis of some aryl‐pyrimidyl, aryl‐thiazolyl and aryl‐thienyl sulphides

AbstractThe synthesis of some heterocyclic‐aromatic sulphides with potential acaricidal properties is described. The benzene nucleus in these sulphides is substituted either with a para‐chlorine atom or with three chlorine atoms in positions 2,4 and 5. The heterocyclic nuclei are pyrimidine, thiazole and thiophen. These nuclei are either unsubstituted or carry a halogen substituent; only in the thiophen series a nitro group is substituted.

Synthesis and physiological properties of some heterocyclic‐aromatic sulphides and sulphones: III Synthesis of some heterocyclic‐aromatic sulphones

AbstractThe synthesis of some heterocyclic‐aromatic sulphones with potential acaricidal properties is described. The benzene nucleus in these sulphones is substituted either with a para‐chlorine atom or with three chlorine atoms in positions 2, 4 and 5. The heterocyclic nuclei used are pyridine, pyrimidine, thiazole or thiophen. Apart from the sulphonyl substituent, these nuclei are unsubstituted or carry a halogen substituent; only in the thiophen series a nitro group is substituted in the heterocyclic nucleus. From the aryl‐pyridyl sulphones the corresponding N‐oxydes have been prepared.

Synthesis and physiological properties of some heterocyclic‐aromatic sulphides and sulphones. I. Synthesis of some aryl‐pyridyl sulphides

AbstractThe preparation of some aryl‐pyridyl sulphides with potential acaricidal properties is described. In the compounds synthesized the benzene nucleus is substituted with a para‐chlorine atom or with three chlorine atoms in positions 2, 4 and 5. Position 5 in the pyridine nucleus is either unsubstituted or carries a chlorine substituent. From a few aryl‐pyridyl sulphides the corresponding N‐oxides have been prepared.

Trifluoperazine (Stelazine) in Psychoneuroses

Trifluoperazine (Stelazine) is a phenothiazine derivative and is 2-trifluoromethyl-10-(3′ 1″-methyl piperazinyl-4″-propyl) phenothiazine dihydrochloride. It is related to prochlorperazine, and in fact differs only in having a trifluoromethyl group in place of the latter's chlorine atom in position 2 of the nucleus. However, in laboratory studies, tests based on the inhibition of conditioned responses have indicated that this compound was 5 times as effective as prochlorperazine and 10 times as potent as chlorpromazine on a weight for weight basis.

Syntheses of Chlorinated Copper Phthalocyanines from Chlorophthalic Anhydrides

Abstract Syntheses of chlorinated copper phthalocyanines from various chlorophthalic anhydrides were conducted. Formation of phthalocyanine depends upon the contents and positions of chlorine atoms of chlorophthalic anhydrides.