Antianexiety activity of pyridine derivatives synthesized from 2-chloro-6-hydrazino-isonicotinic acid hydrazide

A series of oxadiazole pyridine derivatives were synthesized by using 2-chloro-6-hydrazinoisonicotinic acid hydrazide as starting material. Treatment of the hydrazide with carbon disulfide to afford the oxadiazole derivative, which was treated with 5-methyl-2-furancarbaldehyde, formic acid, acetic acid/acetic anhydride, or phthalic anhydride to yield the corresponding pyridinodiazoles and on imide. Condensation of the hydrazide with p-fluorobenzaldehyde in ethanol or acetic acid in the presence of sodium acetate afforded hydrazone and oxadiazole derivatives, which were acetylated and cyclized with acetic anhydride to N-acetyloxadiazole derivatives. The hydrazone was treated with acetic acid in the presence of sodium acetate, or bromine water/sodium acetate to give on oxadiazole, while it was cyclized with chloroacetyl chloride in the presence of TEA to oxoazetidinaminoisonicotinamide. Finally, condensation of the hydrazide with acid anhydrides in refluxing glacial acetic acid afforded the corresponding bisimide derivatives. The pharmacological screening showed that many of these obtained compounds have good antianexiety activity comparable to diazepam^® as positive control.     

Line shapes and satellites in high-resolution x-ray photoelectron spectra of large pi-conjugated organic molecules

We present a high-resolution C1s and O1 s x-ray photoemission (XPS) study for condensed films of pi-conjugated organic molecules, namely, of the anhydrides 3,4,9,10-perylene-tetracarboxylic acid dianhydride, 1,4,5,8-naphthalene-tetracarboxylic acid dianhydride, 1,8-naphthalene dicarboxylic acid anhydride, and benzoperylene-(1,8)-dicarboxylic acid anhydride as well as the quinoic acenaphthenequinone. Although the functional groups are identical for the anhydrides, the molecules show very different photoemission fine structure thus providing a detailed fingerprint. A simultaneous peak fit analysis of the XPS spectra of all molecules allows to consistently determine the ionization potentials of all chemically different carbon and oxygen atoms. Additional structures in the C1s and O1s spectra are interpreted as shakeup satellites and assigned with the help of singles and doubles configuration interaction calculations. These satellites provide further information on multielectron excitations and must be taken into account for quantitative investigations.     

Bi-acylation of cellulose: determining the relative reactivities of the acetyl and fatty-acyl moieties

The global reaction between acetic anhydride and a fatty acid yields, at equilibrium, an asymmetric acetic-aliphatic anhydride in a medium containing finally: acetic-fatty anhydride, acetic anhydride, fatty acid, acetic acid and fatty anhydride. No solvent or catalyst was used to evaluate the impact of the actual reactivity of the anhydrides. The competition between the formation of acetyl and fatty acyl ester functions was evaluated by determining the ratio of acetyl/fatty acyl groups grafted on solid cellulose. The influence of temperature, reaction time, and length of fatty chain on the total degree of substitution and on the ratio of acetyl/fatty acyl ester functions was investigated. For the first time, a correlation has been established between esterification and the length of the aliphatic chain of the fatty acid. Reactivity of the medium decreased with the number of carbons in the fatty acid, raised to the power 2.37.     

Phosphorus containing mixed anhydrides--their preparation, labile behaviour and potential routes to their stabilisation

Simple mixed anhydrides are known to pose synthetic difficulties relating to their thermal lability and ways to stabilise such mixed anhydride systems by relying on either electronic or steric effects were therefore explored. Thus, a series of acyloxyphosphines and acylphosphites derived from either propanoic acid or phenylacetic acid were prepared and their in solution stability assessed. These compounds were, where stability allowed, fully characterised using standard analytical techniques. NMR studies, in particular, unearthed interesting coupling behaviour for a number of the acyloxyphosphines and acylphosphites as well as their rearrangement products which could be linked to their chiral nature. Furthermore, the crystal structures for three of the prepared mixed anhydrides were determined using X-ray crystallography and are reported herein.     

Determination of aliphatic anhydrides and acids by reversed-phase liquid chromatography

Few chromatography methods have been reported for the determination of anhydrides in mixtures or as mixed anhydrides. The potential reactivity of anhydrides with water and other common eluent components complicates possible schemes for separation and analysis. By optimizing variables that affect hydrolysis, including the stationary phase, conditions can be found to successfully analyze anhydrides as reactive as acetic anhydride. The corresponding acids can be determined at the same time. The effect of the stationary phase on anhydride hydrolysis rates may prove to be a sensitive means of probing stationary phase chemistry.     

Heterocyclic analogs of pleiadiene. XV. Direct acylation of perimidines in the naphthalene ring. Synthesis of 4 (9)- and 6 (7)-acylperimidines

It is shown that perimidines and aceperimidines are acylated by carboxylic acid or their anhydrides in polyphosphoric acid to give 6(7)-acylperimidines at 70–80° (kinetic control) and 4(9)-acylperimidines at 120–150° (thermodynamic control). Acetylation of the perimidines with acetic anhydride also takes place in the presence of perchloric acid.     

羧酸衍生物取代甲基苯基聚硅烷制备杂取代聚硅烷

以甲基苯基聚硅烷　(PhSiMe　) n为原料 ,在无水AlCl3 存在下 ,通过与酰氯、酸酐及酯的取代反应合成了氯代聚硅烷及一系列共聚物 .在乙酰氯的作用下 ,　(PhSiMe　) n上的苯基能够被近乎完全的取代而生成氯代聚硅烷 .一元酸酐 (乙酸酐和丙酸酐 )在用酰氧基部分取代聚硅烷上苯基的同时 ,进行得更多的还是Cl取代 .而顺丁烯二酸酐、邻苯二甲酸酐和乙酸乙酯则只进行不完全的Cl取代 ,根据分子活性的不同得到取代比率各不相同的共聚物 .初步分析了各反应的过程 ,讨论了影响反应的因素 ,同时对于各产物的荧光和紫外特性也进行了分析和讨论     

Steric effects in the uncatalyzed and DMAP-catalyzed acylation of alcohols-quantifying the window of opportunity in kinetic resolution experiments

The kinetics of the reaction of several alcohols (benzyl alcohol, ethanol, 1-phenylethanol, cyclohexanol, and 1-methyl-1-phenylethanol) with a selection of anhydrides (acetic anyhydride, propionic anhydride, isobutyric anhydride, isovaleric anhydride, and pivalic anhydride) as catalyzed by 4-(N,N-dimethylamino)pyridine (DMAP)/triethyl amine have been studied in CH(2)Cl(2) at 20 degrees C. In all cases the reaction kinetics can be described by rate laws containing a DMAP-catalyzed term and an uncatalyzed (background) term. The rate constants for the background reaction respond sensitively to changes in the steric demand of the alcohol and the anhydride substrates, making the reaction of cyclohexanol with acetic anhydride 526 times faster than the reaction with pivalic anhydride. Steric effects are even larger for the catalyzed reaction and the reactivity difference between acetic and pivalic anhydride exceeds a factor of 8000 for the reaction of cyclohexanol. There is, however, no linear correlation between the steric effects on the catalyzed and the uncatalyzed part. As a consequence there are substrate combinations with dominating catalytic terms (such as the reaction of benzyl alcohol with isobutyric anhydride), while other substrate combinations (such as the reaction of cyclohexanol with pivalic anhydride) are characterized through a dominating background process. The implications of these findings for the kinetic resolution of alcohols are discussed.     

Synthesis of alkyl and alkenyl furyl sulfoxides and their behavior in the pummerer reaction

Oxidation of alkyl(alkenyl) furyl sulfides by hydrogen peroxide in glacial acetic acid affords alkyl(alkenyl) furyl sulfoxides, which react with acetic acid, acetic anhydride, and a mixture of acetic and trifluoroacetic anhydrides to give -acyloxy-substituted and unsaturated sulfides as products, while for allyl 2-(5-methylfuryl) sulfoxide a thienofuran compound is obtained.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1601–1604, December, 1987.     

Determination of maleic anhydride in occupational atmospheres

Maleic anhydride has many uses in industry, but workers' exposure to it is poorly known. Our new method allows airborne maleic anhydride to be determined with a limit of quantification of 1 microg/m3 per 12 1 of air, i.e., the concentration of about 0.01 times the occupational exposure standard (0.4 mg/m3). Air samples are collected in Tenax tubes containing sodium sulfate as a drying agent. Maleic anhydride is eluted with methyl tert.-butyl ether containing 5% acetonitrile and 0.1% acetic anhydride, and determined by capillary gas chromatography with electron-capture detection without interference from generic anhydrides. The tested method suits both long-term and short-term measurements.     

Aliphatic polyimides from phenylene bis(succinic anhydride) and bis(glutaric anhydride)

Meta and para derivatives of phenylene bis(succinic anhydride) and bis(glutaric anhydride) were obtained from 1,3- and 1,4-bis(β-cyano-β-carbethoxyvinyl)benzene with potassium cyanide or Meldrum acid followed by hydrolysis with concentrated hydrochloric acid and dehydration with acetic anhydride. Aliphatic polyimides were prepared from these anhydrides with six aromatic diamines through thermal ring closure of polyamic acids obtained by solution polymerization in dimethylacetamide, and thermal stability of these polyimides was examined by thermogravimetric analysis.     

Molecular complexes of antipsychotic pharmaceutical parent molecule phenothiazine and unsaturated acid anhydrides

The charge-transfer complexes (CTC) between a parent molecule of antipsychotic pharmaceuticals, phenothiazine, and seven unsaturated acid anhydrides, 1,4,5,8-naphtalenetetracarboxylic dianhydride, diphenic anhydride, maleic anhydride (MA), 3,4,5,6-tetrahydrophthalic anhydride (THPA), 3-hydroxy-1,8-naphthalic anhydride (HONA), 4-chloro-1,8-naphthalic anhydride (ClNA), and 1,8-naphthalic anhydride (NA) were studied using IR and UV spectroscopy. Stability constants (K) at different temperatures were measured, and based on the K's DeltaH and DeltaS were calculated. The values of electron affinity (E(A)) of anhydrides were obtained according to Mulliken's theory. The results show that phenothiazine is an excellent donor and has strong ability to complex with the carbonyl group, and the E(A) values have good linear relationships with DeltaH and K, respectively. The solvent effect on CTCs was also determined and explained. The CTC of phenothiazine-succinic anhydride (SA) was studied under the same conditions. It was deduced from the results obtained that there were two charge-accepting centers in the unsaturated acid anhydrides when they formed CTCs with phenothiazine. The first one was carbon atom of the two carbonyl groups and the second one was their -C=C- in the molecules.     

Investigation of the reaction of some unsaturated dicarboxylic acid anhydrides with cyclic carbonates

This work reports attempts to extend to unsaturated anhydrides the rapid reaction of dicarboxylic acid anhydrides with ethylene carbonate to form polymer directly. The reaction of unsaturated diacid anhydrides with two cyclic carbonates, ethylene and propylene carbonate, leads to gelled products whenever the anhydride is capable of Michael addition, while an anhydride without such unsaturation gave linear polymer in- stead. The GC/MS results, along with efforts to trap radical reactions, support Michael addition as an explanation of gelation in these systems.     

Strategic Utilization of Multifunctional Carbene for Direct Synthesis of Carboxylic–Phosphinic Mixed Anhydride from CO2

Direct synthesis of carboxylic–phosphinic mixed anhydrides has been achieved by treating carbon dioxide with N‐phosphine oxide‐substituted imidazolylidenes (PoxIms) that contain both nucleophilic carbene and electrophilic phosphorus moieties. This novel mixed anhydride was efficiently derivatized into an ester, an amide, and an unsymmetrical ketone via transformation into its corresponding imidazolium salt followed by a dual substitution reaction. The presented work used well‐designed multifunctional carbene reagents to establish a novel utility for carbon dioxide in organic synthesis.     

Addition of a Silyl Ketene Acetal to α,β-Unsaturated Cyclic Anhydrides

Addition of [1-methoxy-2 methyl-1-propenyl)-oxy] trimethylsilane (MTS) to unsymmetrical α,β-unsaturated cyclic anhydrides (namely, itaconic anhydride and citraconic anhydride) as well as symmetrical anhydrides (namely, maleic anhydride and 2,3-dimethylmaleic anhydride) was investigated. Itaconic anhydride isomerizes to citraconic anhydride in the presence of MTS. In the presence of Lewis acid catalysts (Yb(OTf)₃/CH₂Cl₂), MTS adds to itaconic anhydride at room temperature in a 1,4-fashion. 1,2-Addition is the preferred pathway with both 2,3-dimethyl maleic anhydride and citraconic anhydride.     

Polyimides from 4,4′-(alkylene-α,ω-dioxy) bis(phenylsuccinic anhydride)s and bis(phenylglutaric anhydride)s

4,4′-(Alkylene-α,ω-dioxy)bis(phenylsuccinic anhydride)s and bis(glutaric anhydride)s were obtained by the condensation of 4,4′-diformyl-α,ω-diphenoxyalkanes with ethyl cyanoacetate followed by the addition of potassium cyanide or meldrum acid (2,2-dimenthyl-1,3-dioxane-4,6-dione), hydrolysis with concentrated hydrochloric acid, and dehydration with acetic anhydride. Alkylene groups were ethylene, trimethylene, and tetramethylene. Polyimides were prepared from these anhydrides with 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl sulfide, and 4,4′-diaminodiphenylmethane through thermal ring closure of polyamic acids obtained by solution polymerization in dimethylacetamide, and thermal stability of these polyimide film was examined by thermogravimetric analysis.     

Derivatives of 2-(3'-coumarinyl)-1, 3-indandione

The possibility of the direct preparation of 2-(3'-coumarinyl)-1,3-indandione and its derivatives by condensing phthalic and substituted phthalic anhydrides with 3-coumarinylacetic acid in acetic anhydride solution in the presence of triethylamine has been shown. The bromination and hydroxymethylation of 2-(3'coumarinyl)-1,3-indandione and its substituted derivatives have been performed.     

Quantitative anodic generation of cobalt (III) at glassy carbon in acetic acid. Coulometric titrations with the generated reagent

Conditions are established for quantitative electrochemical generation of cobalt (III) at a glassy carbon working electrode in anhydrous acetic acid in the presence of potassium acetate, sodium acetate or sodium perchlorate. In anhydrous alkali-metal acetate solutions cobalt (III) is as stable as in the presence of acetic anhydride. The concentration of cobalt(III) in the solution is considerably decreased in the presence of small amounts of water. This phenomenon is much more pronounced in sodium perchlorate supporting electrolyte. Coulometric titration methods for the determination of hydroquinone, 2-methylhydroquinone and ascorbic acid with the generated oxidant have been developed. The errors of the determinations are less than ±2%.     

磺化笼型介孔碳催化的1,1-二乙酸酯的选择性合成

以磺化的笼型介孔碳为催化剂温和、高效、高选择性地合成了缩羰基二乙酸酯. 在室温和无溶剂条件下,用磺化的笼型介孔碳作催化剂使醛类化合物与乙酸酐之间在5~12 min内反应生成1,1-二乙酸酯,产率高达89%~98%. 在相同条件下酮类化合物不会发生此反应. 反应后催化剂经过简单的处理即可回收利用,回收利用7次活性无明显降低.     

Synthesis of 4-oxo-1,3-benz- and naphthoxazinium salts from o-hydroxyarylamides

The acid-catalyzed acylation of primary and secondary o-hydroxyarylamides, the probable reaction scheme, and the possibility of the formation of 4-oxo-1,3-arenooxazinium salts and analogs in the reaction of amides of salicylic, coumaric, and 1-hydroxy- and 3-hydroxynaphthoic acids and their N-alkyl(aryl)derivatives with excess amounts of aliphatic acid anhydrides and 70% perchloric acid, as well as by the acid cyclization of O- and N-mono- and diacyl derivatives of these amides, are examined. Twelve previously unknown 2-alkyl- and 2-styryl-4-oxo-1,3-naphth[3,2-e]-and -[1,2-e]oxazinium perchlorates were synthesized. N-Methyl- and N-benzylamides of 8-acetoxy-1-naphthoic acid are formed instead of the expected peri-cyclic analogs of oxazinium salts in the reaction of 8-hydroxy-1-naphthoic acid anilides with acetic anhydride and perchloric acid.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1611–1616, December, 1979.Original article submitted May 31, 1978; revision submitted April 2, 1979.