An efficient ultrasonic synthetic approach,DFT study,and molecular docking of 6a-hydroxy-9-nitro-6,6a-dihydro-isoindolo[2,1-a] quinazoline-5,11-dione derivatives as algaecides for refining wastewater

In the present work, reaction of 3-nitrophthalic anhydride with anthranilic acid to afford the corresponding anthranil that is treated with acetic anhydride that yielded the 2-benzoxazinonyl-5-nitrobenzoic acid (BNBA) could be isomerized to the stereogenic 9-nitrobenzoxazinone[2,3-a]isoindolinone acetate (NBIA) via basic reaction conditions. A reaction of the BNBA→NBIA was allowed with series of nitrogen nucleophiles such as formamide and hydrazine derivatives, for example, hydrazine hydrate, hydroxyl amine, acetic hydrazide, thiosemicarbazide, thiocarboihydrazide, and some amino acid, for example, glycine, alanine, and some aliphatic amine, for example, octyl amine, decyl amine, and aromatic amine, for example, aniline, o-toluidine, 4-aminobenzoic acid, and carbon nucleophiles such as malononitrile and diethylmalonate. The basicity of previous nucleophiles and thermal stability of the products can be controlled on the course of reaction. The chemical structure of the synthesized compounds can be confirmed by micro-analytical, spectral data, and they are optimized by quantum chemical parameters (DFT study) to identify the thermal stability of the products. The data obtained from the molecular modeling were correlated with those obtained from the biological screening. A novel sequence of quinazoline derivatives were synthesized, evaluated for their algaecides activity against compounds 1 , 2b , and 6 that showed the highest algaecides activities of this series with relatively low toxicity in the median lethal dose test. The obtained results proved that the most active compounds could be useful models for future design, adaptation, and investigation to construct more active analogs.     

Untersuchungen an Stickstoff-Chlor-Verbindungen. VIII. Tieftemperatur-Umsetzungen von Aminen mit Chlordioxid in wasserfreien Medien – Darstellung von Chlorsäureamiden und Amin-Chlordioxid-Addukten

Studies on Nitrogen-Chlorine Compounds. VIII. Low Temperature Reactions between Amines and Chlorine Dioxide in Non-Aqeous Solutions – Preparation of Chloric Acid Amides and Adducts between Amines and Chlorine Dioxide The radicalic redox reaction between amines and chlorine dioxide leads to different reaction products dependent on the kind of amine: reactive protons in α position to nitrogen are abstracted, and azomethinium chlorite is formed besides the chlorite or chlorate of the protonated base. In case of absence of reactive protons in α position to nitrogen these are abstracted from nitrogen if possible; amidochlorates are formed – which are described here for the first time – besides the salt of the protonated base. In case of absence of reactive protons at nitrogen the reaction stops after formation of an adduct between amine and chlorine dioxide. For this several new examples are reported.     

Surface modification. II. Functionalization of solid surfaces with vinylic monomers

A new method to functionalize surfaces of solid substrates such as glass, silicon crystals, and silica microspheres with appropriate vinylic monomers, i.e., methyl vinyl ketone, methyl acrylate, methacrolein, and acrolein, is described. The surface modification process was performed through the following sequence of reactions: (a) derivatization of the surfaces with to-nitrile groups by interacting the substrates with SiCl₃(CH₂)₃CN; (b) subsequent reduction of the a)-nitrile groups with diborane to w-amine groups; (c) binding of the vinylic monomers to the surfaces via the to-amine groups. pK_1/2 of the surface primary amine groups, as determined by contact angle titration, was found to be 2–4 units lower than the pK_1/2 values of primary amine analogous in solution. Methyl vinyl ketone and methyl acrylate were covalently bound to the amine surfaces only under basic conditions via the Michael addition reaction. Methacrolein and acrolein were covalently bound to the amine surfaces under both acidic and basic conditions via two major reactions: the Michael addition reaction and Schiff base bond formation. The concentration of the aldehyde groups of the surfaces obtained by the reaction with methacrolein and acrolein was significantly higher than that obtained using the common, published method in which glutaraldehyde interacts with the amine surfaces.     

Synthesis of some 4-substituted-2-(o-halogenophenyl)-1,2,3-triazoles

Mesoaldehyde 1,3-dioxime was treated with either 2,4,6-trichlorophenyl- (a), o-fluorophenyl- (b), or o-bromophenyl- (c) hydrazine to give the corresponding mesoaldehyde 1,3-dioxime-2-halogenophenylhydrazones (1a,b,c). The latter were O-acetylated with acetic anhydride, and cyclized to triazole 4-oximes (3b, c) or triazole 4-O-acetyloximes ( 6a,b,c ) with cesium carbonate, then converted to nitriles ( 7a,b,c ) by refluxing with acetic anhydride followed by pyrolysis, or to aldehydes ( 4a,b,c ) by hydrolysis. The nitriles ( 7a,b,c ) were also converted to acids ( 9a,b,c ), esters ( 10a,b,c ), amides ( 8a,c ), an alcohol (11a), and an amine ( 12a ). In addition, tetrazoles of two types were prepared. The first ( 13d,e ) were obtained from the acid chlorides by the action of 5-aminotetrazole, whereas the second ( 14f ) was produced from the respective nitrile by the action of ammonium azide.     

Reactive compatibilization of SAN/EPR blends: effect of the kinetics of the compatibilization reaction on the interfacial adhesion

The very poor adhesion between films of styrene and acrylonitrile random copolymer (SAN) and maleic anhydride grafted polypropylene (PP‐g‐MA) can be dramatically improved by an intermediate thin layer of SAN bearing groups reactive toward maleic anhydride. The rate of the interfacial reaction, which is controlled by the reactive groups attached to SAN (amine vs. carbamate) and by the method used to build up the sandwich assembly, has a decisive effect on the capability of the SAN‐g‐PP graft copolymer formed at the interface to improve the fracture toughness in direct dependence on its molecular architecture.     

Chemical reactions and reactivity of primary,secondary, and tertiary diamines with acid functionalized polymers

Reactive melt processing of different types of diamines with polyethylene containing carboxylic acid groups and polystyrene containing anhydride groups was carried out. The reactivity of primary, secondary, and tertiary diamines with these acid polymers was determined using various techniques. Molecular weight increases due to crosslinking were observed through (1) changes in the torque during the reactive processing, (2) decrease in melt flow indices, and (3) decrease in solubility of the reaction products. The chemical compositions of the reaction products were examined by Fourier transform infrared (FTIR) spectroscopy. Thermal analysis using differential scanning calorimetry (DSC) was carried out to determine the crystallization behavior, glass transition temperatures, and thermal stabilities of the reaction products. Results show that the primary amine is the most reactive towards carboxylic acid or anhydride groups followed by the secondary and then the tertiary amine. Anhydride groups on polymers are of higher activity towards secondary or primary amino groups than carboxylic acid groups in the nucleophilic acyl substitution reactions. Reaction products crosslinked with the primary diamine are less stable than their parent acidic polymers. On the other hand, crosslinking with the secondary or tertiary diamine gives products with higher thermal stability than the parent acidic polymers. The formation of reversible and irreversible crosslinks with different types of diamines is also reported. © 1992 John Wiley & Sons, Inc.     

The reactions of tetrafluoroethylene oligomers: V. The reactions of perfluoro-3,4-dimethyl-4-ethylhexene-(2) with thionucleophiles and the chemical transformations of reaction products

The reactions of perfluoro-3,4-dimethyl-4-ethylhexene-(2) (1) with s-nucleophiles such as benzylthiol, allylthiol, phenylthiol and the chemical transformations of these reaction products were reported. 1 reacted with S-nucleophiles to give four types of isomeric products. At ?30～ ?60°C, in ether, kinetically controlled product 2 (a, b, c) were formed. Compound 2 might be converted directly into the thermodynamically stable products 3 (a, b,) in DMF-KF at r.t., At 100°C, 2 was converted to 4 (a, b, c) via intramolecular rearrangement. In KF-DMF at r.t., 4 was isomerized to 5 (a, b, c). 2a also reacted with another mole of thiol to give the corresponding disulfide 6 and hydrogen-containing olefin 7a as well as the disubstituted product 8a in DMF, but only give 3a and 9a in ether-Et₃N. The reaction of 2a with methyl alcohol gave only a small amounts of 3a and 10a. The reaction of 2b with dimethylamine was complex and 3b and 11 were obtained in low yield.     

Product and Mechanism of Gas‐phase Pyrolysis of 2‐arylidinehydrazinopyrimidines: Interesting Route to Condensed Heterocycles[1]

Gas‐phase pyrolysis of N‐arylidine‐N′‐pyrimidin‐2‐yl‐hydrazine derivatives 1a , 1b , 1c , 1d , 1e gave the corresponding arylnitriles 2a , 2b , 2c , 2d , 2e , 2‐aminopyrimidine 3 , 3‐phenyl‐1,2,4‐triazolo[4,3‐a]pyrimidines 4 , 2‐phenyl‐1,2,4‐triazolo[1,5‐a]pyrimidines 5 , 2,4,5‐triphenyl‐1H‐imidazole 6 , and 2,3‐diphenylquinoline 7 . The analyses of the reaction products are reported and used to elucidate the mechanism of the pyrolytic process.     

Polyetherimides. I. Preparation of dianhydrides containing aromatic ether groups

A general synthetic method and characterization of bis(ether anhydride)s, the ether containing aromatic dianhydrides of the following structure, are presented. The method involves aromatic nitro-displacement of N-substituted 3- or 4-nitrophthalimide with bisphenoxides to form N-substituted arylene-bis(phthalimido)ethers or bis(ether imide)s. Sixteen structurally different bis(ether imide)s have been prepared and subsequently converted to the corresponding bis(ether anhydride)s. Bis(ether anhydride)s are stable crystalline compounds of a moderate reactivity. Unlike highly reactive dianydrides such as pyromellitic and benzophenonetetracarboxylic dianhydrides bis(ether anhydride)s are semipermanently stable against hydrolysis in the presence of atmospheric moisture.     

Mechanism of amine catalyzed isomerization of itaconic anhydride to citraconic anhydride: Citraconamic acid formation

The amine catalyzed isomerization of itaconic to citraconic anhydride has been investigated. Studies show that the rate of isomerization is dependent on the base strength and solvent media. Triethylamine causes complete isomerization within 5 min at room temperature in acetone or chloroform solvent, whereas aromatic tertiary amines such as pyridine and N,N-dimethylaniline require time perods as long as 23h at room temperature for almost complete isomerization. In the presence of aniline no isomerization occures even under acetone reflux conditions over a 24 h period. For the preparation of citraconamic acids from itaconic anhydrides and aliphatic diamines nuclear magnetic resonance and infrared spectroscopic evidence is presented to support the reaction path of initial isomerization of itaconic anhydride to citraconic anhydride followed by amine attack on the anhydride to form the corresponding cis-citraconamic acids. The mechanism of isomerization of itaconic to citraconic acids is proposed.     

Characterization of moisture-sensitive raw materials with simple spectroscopic techniques

The quality of raw materials used in a synthetic process needs to be properly controlled in order to ensure optimal reaction conversion and desired quality of the resulting product. For air and water sensitive raw materials, quantitative analysis can be a challenging task. Spectroscopic techniques possess advantages of simple operation, fast analysis, low consumable costs and high sample throughput for the analysis of reactive raw materials. Three case studies utilizing spectroscopic analysis for air and water sensitive materials are discussed. First, FT-IR spectroscopy was utilized to determine the amount of residual acetic acid in acetic anhydride key raw material. Acetic anhydride was used in a methylenation reaction where the presence of residual acetic acid could quench a base used in the reaction, leading to incomplete conversion. A simple, one-frequency calibration method was developed to quantify acetic acid in acetic anhydride (2-35 wt.%). Next, a novel near infrared reflectance spectroscopy (NIRS) method was used to determine the concentration of diisobutyl aluminum hydride (DIBAL-H) in toluene. DIBAL-H is a highly reactive and moisture-sensitive reagent used as a key raw material for the reduction of an active intermediate. A calibration method based on one-frequency was also developed to determine the concentration of DIBAL-H in toluene (0-1.5 mole/L). Finally, a NIRS method based on partial least squares regression (PLS) was developed to quantify p-toluenesulfonic acid in p-toluenesulfonic anhydride, which is not amenable to chromatographic analysis.     

Pyrrole–Aminopyrimidine Ensembles: Cycloaddition of Guanidine to Acylethynylpyrroles

An efficient method for the synthesis of pharmaceutically prospective pyrrole–aminopyrimidine ensembles (in up to 91% yield) by the cyclocondensation of easily available acylethynylpyrroles with guanidine nitrate has been developed. The reaction proceeds under heating (110–115 °C, 4 h) in the KOH/DMSO system. In the case of 2-benzoylethynylpyrrole, the unexpected addition of the formed pyrrole–aminopyrimidine as N- (NH moiety of the pyrrole ring) and C- (CH of aminopyrimidine) nucleophiles to the triple bond is observed.     

Functional copolymer/organo‐MMT nanoarchitectures. XIX. Nanofabrication and characterization of poly(MA‐alt‐1‐octadecene)‐g‐PLA layered silicate nanocomposites with nanoporous core–shell morphology

Novel bioengineering functional copolymer‐g‐biopolymer‐based layered silicate nanocomposites were fabricated by catalytic interlamellar bulk graft copolymerization of L‐lactic acid (LA) monomer onto alternating copolymer of maleic anhydride (MA) with 1‐octadecene as a reactive matrix polymer in the presence of preintercalated LA…organo‐MMT clay (reactive ODA‐MMT and non‐reactive DMDA‐MMT) complexes as nanofillers and tin(oct)₂ as a catalyst under vacuum at 80°C. To characterize the functional copolymer layered silicate nanocomposites and understand the mechanism of in situ processing, interfacial interactions and nanostructure formation in these nanosystems, we have utilized a combination of variuous methods such as FT‐IR spectroscopy, X‐ray diffraction (XRD), dynamic mechanical (DMA), thermal (DSC and TGA‐DTG), SEM and TEM morphology. It was found that in situ graft copolymerization occurred through the following steps: (i) esterification of anhydride units of copolymer with LA; (ii) intercalation of LA between silicate galleries; (iii) intercalation of matrix copolymer into silicate layers through in situ amidization of anhydride units with octadecyl amine intercalant; and (iv) interlamellar graft copolymerization via in situ intercalating/exfoliating processing. The main properties and observed micro‐ and nanoporous surface and internal core–shell morphology of the nanocomposites significantly depend on the origin of MMT clays and type of in situ processing (ion exchanging, amidization reaction, strong H‐bonding and self‐organized hydrophobic/hydrophilic interfacial interactions). This developed approach can be applied to a wide range of anhydride‐containing copolymers such as random, alternating and graft copolymers of MA to synthesize new generation of polymer‐g‐biopolymer silicate layered nanocomposites and nanofibers for nanoengineering and nanomedicine applications. Copyright © 2014 John Wiley & Sons, Ltd.     

Retrosynthetic reactions in mass spectrometry. Deacylation of ortho phthalamic acids under electron impact

Ortho Phthalamic acids under electron impact show a retrosynthetic reaction leading to both phthalic anhydride and amine complementary ions, the corresponding neutrals of which are the usual synthetic precursors of the original compounds. The single case of a primary amine derivative is examined, which shows the formation of [M? H₂O]^+˙ ions having the structure of the related N-substituted imide, by a process which parallels a well known thermal reaction. It also gives the species [C₈H₆NO₂]⁺ (of the same nominal mass as phthalic anhydride), the structure of which is still under study. Ionic structures are supported by collision induced mass analyzed ion kinetic energy spectra.     

Novel heterocycles. 10. Reactions of 1,3,2-benzodiazaphosphorin-4(1H)-one 2-oxides

Reactions of 1,3-disubstituted-2,3-dihydro-1,3,2-benzodiazaphosphorin-4 (1 H)-one 2-oxides ( 1 ) with various electrophiles were investigated. The treatment of 1 with aldehydes in the absence of a basic catalyst directlyafforded alcohols 7a-h in good yield. The product from the reaction of 1 with chloral, on treatment with sodium hydride, resulted in the formation of a dichloroepoxide ( 8 ). When 1 was allowed to react with isocyanates or isothiocyanates in the presence of triethylamine, amides 10a-e and thioamide 11 were produced in good yield. Compounds 1a and 1b were readily halogenated on their phosphorus atom by treatment with either carbon tetrachloride or carbon tetrabromide and triethylamine. The P-chloro compound 12a reacted with ethanol to furnish the P-ethoxy derivative 13 and, in an attempt to react 12a with bis (2-chloroethyl) amine, anhydride 14 was formed in high yield. Spectral data for the majority of the products are also discussed.     

Silica‐bonded S‐sulfonic Acid as a Recyclable Catalyst for Synthesis of 2,3‐Dihydroquinazolin‐4(1H)‐ones

2,3‐Dihydroquinazolin‐4(1H)‐one derivatives were synthesized via a one‐pot, three component reaction of isatoic anhydride and an aromatic aldehyde with ammonium acetate or primary amine catalyzed by silica‐bonded S‐sulfonic acid in ethanol at 80°C. The reaction work‐up is simple and the catalyst is easily separated from the products by filtration. The heterogeneous catalyst was recycled for ten runs upon the condensation reaction of isatoic anhydride and 4‐chlorobenzaldehyde with ammonium acetate without losing its catalytic activity.     

Model experiments for the interfacial reaction between polymers during reactive polymer blending

Bilayer film Fourier transform infrared (FTIR) model experiments are designed to provide a well-defined interface for study which can be probed by infrared spectroscopy during the interdiffusion and reaction of two reactive polymers. This provides a model experiment to determine the kinetics and extent of reaction between functionalized polymers during reactive polymer blending. This type of experiment provides data on the reaction at a stagnant interface which is necessary for the analysis of the interface while it is simultaneously undergoing deformation. It is also useful as a screening or preliminary experiment on reactive blending systems in that the extent of reaction may be followed for different systems at different temperatures. Experiments reported here trace the reaction of a styrene–maleic anhydride copolymer with two different amine terminated polymers. Results are obtained for the interdiffusion and reaction of a styrene-maleic anhydride copolymer with two amine terminated polymers: a butadiene-acrylonitrile copolymer and Nylon 11. The kinetics from these experiments include contributions due to both interdiffusion and chemical reaction. The chemical reaction kinetics may be isolated from the diffusion kinetics by performing experiments on well-mixed systems which are prepared by casting films of the polymer mixtures from a mutual solvent. © 1994 John Wiley & Sons, Inc.     

Amine/anhydride reaction versus amide/anhydride reaction in polyamide/anhydride carriers

Polyamide 6 (PA6) and poly(metaxylene adipamide) (PAmXD6) were blended in a batch mixer with anhydrides such as phthalic anhydride, n-octadecyl succinic anhydride, and anhydride-grafted ethylene propylene rubber. The melt viscosity, the solution viscosity, and chain end concentration were studied during the mixing. PA was first mixed 5 min to get an homogeneous melt prior to the anhydride addition. The introduction of the anhydride to the molten polyamide resulted in large decreases of melt and solution viscosities and of amine chain end concentrations. The anhydride units react with amine chain ends to form imide groups. The resulting low amine chain end concentration causes hydrolysis reaction to maintain the condensation equilibrium. As a consequence an increased carboxylic chain end concentration is observed. The imide concentration was studied by IR. It was shown that when most of the amine chain ends are consumed, the remaining anhydride reacts with amino groups formed by polyamide hydrolysis. © 1995 John Wiley & Sons, Inc.     

Study of the synthesis of poly(isobutylene-b-amide-11) by polycondensation of α,ω-dianhydride oligoisobutylene with α,ω-diamino oligoamide-11. I. Study of amine–anhydride and amide–anhydride reactions on low molecular weight models and on oligomers and polymers

The side reactions connected with the polycondensation of α,ω-diamino oligoamides and α,ω-dianhydride oligoisobutylenes are studied on low and high molecular weight models. Models for amine and anhydride end groups are dodecylamine and (2-dodecene-1-yl) succinic anhydride, respectively; their reaction is studied in the bulk (170°C) and in solution (142, 152, and 162°C); the products are analyzed by ¹H-, ¹³C-, and ¹H-¹³C-NMR and GPC. Some of these products and the junctions between the blocks are prepared independently. Models of amide groups in the chain are N-dodecyldodecanamide and N-dodecyloctadecanamide; their reaction with anhydride model results in cleavages with formation of imide groups. The results obtained from low molecular weight models are confirmed by studies on oligomers. They show unambiguous by that crosslinking which accompanies the block polycondensation originates from the reaction of amino-end groups with the intermediary acid groups resulting from the amine-anhydride reaction.     

Reactions of 2H-3,1-benzoxazine-2,4-(1H)dione (isatoic anhydride) with anions of 1,4-dihydro-5H-pyrazol-5-ones: Synthesis of pyrazolo[5,1-b]quinazolin-9-ones

Reactions of 2H-3,1-benzoxazine-2,4-(1H)dione (isatoic anhydride) (1) with anions of 1,4-dihydro-5H-pyrazol-5-ones (2) gave pyrazolo[5,1-6]quinazolin-9-ones (3) via the nucleophilic attack of the anion 2b rather than 2a. However, in the case of 5-methoxyisatoic anhydride ( 10c) , both products 3e and 11c were obtained. A new synthetic method of preparation of 5-(alkylthio)-2-aminobenzoic acids (18) was described. These acids (18) were used to synthesize a series of substituted pyrazolo[5,1-b]quinazolin-9-ones (3) .