Acrylonitrile In Presence Research Articles

Solvent-induced partial cyanoethylation and hydroxylation of cyanoethyl group

An investigation has been made on the cyanoethylation of cotton fabric using aqueous sodium hydroxide with acrylonitrile in presence of solvents acetone and ethanol at different concentrations. The hydrolysis of β-cyanoethyl ether of cyanoethylated fabric in presence of solvents is studied. The rate of hydrolysis is enhanced by acetone and ethanol concentration. The formation of various products during hydrolysis is analyzed by infrared spectroscopy method while scanning electron microscopy follows the variations in surface morphology. Some of the physical and chemical properties are also studied. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 183–191, 2006

S-Alkylation-Induced Redox Reactions Leading to Reversible Sulfur−Sulfur Coupling in a Pentamethylcyclopentadienyl Ruthenium(III) Thiolate-Thioether System

Alkylation of [Cp*RuIII(tpdt)] (2) (Cp* = η5-C5Me5, tpdt = η3-S(CH2CH2S-)2) with MeI or Me3OBF4 resulted in the formation of a trans μ-η1-η1-S2 coupled species, [{Cp*RuII}2{μ-η6-(S(CH2)2S(CH2)2SMe)2}]2+ (3) as the predominant product. With MeI the reaction also gave a small amount of [Cp*RuII{η3-S(CH2CH2SMe)2}]I, 4(I), but in the presence of acrylonitrile (AN), the products were 4(I) and [Cp*RuII{η3-S((CH2)2S)2(CH2CHCN)}]I, 5(I), of which the latter was the sole product from the reaction of 2 with AN in the presence of iodine. 2 was electrochemically easily oxidized in a one-electron process; its chemical oxidation with I2 led to the isolation of [{Cp*RuII}2{μ-η6-(S(CH2CH2S)2)2}](I3)2, 6(I3)2, containing a cyclic RuII(μ-S2)2RuII core. A combination of electrochemical, EPR, UV−vis, and NMR experiments indicated that the solution phase chemistry of 3 is governed by its facile reversible dissociation into the mononuclear cation radical (3A). Based on this phenomenon were rationalized the pathways leading to ...

Preparation and Some Properties of a Nanocomposite of Polyacrylonitrile with Acetylene Black

Conducting nanocomposites of polyacrylonitrile (PAN) with acetylene black (AB) were prepared via K2CrO4–NaAsO2 initiated redox polymerization of acrylonitrile in presence of AB suspension in aqueous-methanol medium at 60 °C. Prolonged extraction of PAN–AB composite by DMF failed to extract the loaded polyacrylonitrile completely from the acetylene black, as confirmed by FT IR studies. SEM analyses revealed the formation of agglomerates of particles of nonuniform sizes and shapes. TEM analysis indicated that average particle diameters of the PAN–AB composite were in the range of 120–250 nm. Thermal stability of the PAN–AB composite was appreciably improved relative to that for the unmodified base polymer. The dc conductivity of the PAN–AB composite was in the range of 10−4–10−2 S/cm depending on the amount of AB in the PAN–AB composite, a value remarkably improved relative to that of the PAN homopolymer (>10−11 S/cm).

Generation and Reactions of Diazo‐3,3‐dideuterio‐2‐methylidenecyclopropane and Isomerization of 3′,3′‐Dideuterio‐2′‐methylidenespiro [4,5‐dihydropyrazole‐5,1′‐cyclopropanes] into Isopropenylpyrazoles.

AbstractFor Abstract see ChemInform Abstract in Full Text.

The photo-NOCAS reaction: Trapping an intermediate

Irradiation of a mixture of 1,4-dicyanobenzene, phenanthrene, and 2,3-dimethyl-2-butene in acetonitrile–methanol solvent in the presence of acrylonitrile or methyl acrylate leads to a diversion from the usual photo-NOCAS product formation towards products that result from the formal addition of methanol and electrophilic alkenes to the butene.Key words: photo-NOCAS, photoinduced electron transfer, photosubstitution, photoaddition, redox photosensitization, alkene, 2-methoxyalkyl radical.

Cyanoethylation of Cassia tora Gum

AbstractCyanoethylation of Cassia tora gum was carried out with acrylonitrile in presence of sodium hydroxide under different reaction conditions. Variables studied were concentrations of sodium hydroxide and acrylonitrile, reaction temperature and time. The degree of substitution, reaction efficiency and total extent of etherification were determined. The optimum conditions for preparing cyanoethyl Cassia tora gum (DS 0.44) were 0.608 mol acrylonitrile and 0.625 mol sodium hydroxide at 30 °C for 4 h. Rheological properties of cyanoethyl Cassia tora gum solutions showed non‐Newtonian pseudoplastic behavior regardless of the degree of substitution (DS). At a constant rate of shear the apparent viscosity of cyanoethyl Cassia tora gum solutions increased with the increase in %N of the product.

Generation and reactions of diazo-3,3-dideuterio-2-methylidenecyclopropane and isomerization of 3",3"-dideuterio-2"-methylidenespiro[4,5-dihydropyrazole-5,1"-cyclopropanes] into isopropenylpyrazoles

N-(1,3,3-Trideuterio-2-methylidenecyclopropyl)-N-nitrosourea was synthesized and its decomposition on treatment with K2CO3 in the presence of acrylonitrile and ethyl acrylate or on treatment with MeONa in the absence of unsaturated substrates was studied. The rate of decomposition of the nitrosourea is much lower than that of the nondeuterated analog. The use of acrylates for trapping the intermediate 3,3-dideuterio-1-diazo-2-methylidenecyclopropane results in the corresponding 2"-methylidenespiro[4,5-dihydropyrazole-5,1"-cyclopropanes] containing two deuterium atoms in the cyclopropane fragment. The resulting dihydropyrazoles are isomerized almost entirely over a period of 1—3 days to give a mixture (∼1 : 1) of isopropenylpyrazoles in which both deuterium atoms occur either in the methyl or in the methylidene groups of the isopropenyl substituent. A possible mechanism of this transformation is considered.

Ninhydrin as a Source of Naphthoquinone Acetals and Benzocycloheptenetrione Derivatives, and the Trapping of an Oxacarbene Derived from a Cyclopentanone

1,3-Bis(ethylenedioxy)-2-indanone (2) was shown to react with some dienophiles to give naphthoquinone acetals under photochemical reaction conditions, presumably by photodecarbonylation via the corresponding ortho-quinodimethane. With maleic anhydride the highly oxygenated benzocycloheptane derivative rac-12 was obtained in good yield. In a similar manner, upon irradiation in the presence of acrylonitrile a 2:1 mixture of ring-expanded regioisomers rac-13 and rac-14 was obtained. Irradiation in the presence of fumarodinitrile unexpectedly gave the spirocyclic compound rac-15, which was characterized by X-ray crystallography. rac-15 is the trapping product of oxacarbene 16, thus demonstrating a rare case of a ring expansion of a cyclopentanone to give a six-membered ring oxacarbene, here leading to an orthoester. (© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)

Theoretical study on the mechanism of the domino reactions of tertiary α-cyano-enamines and dimethyl acetylenedicarboxylate

The mechanisms of the domino reaction between dimethyl acetylenedicarboxylate, 1, and 2-(N,N-dimethylamino)acrylonitrile, 2, and these in presence of acrylonitrile have been theoretically studied using ab initio methods. These domino reactions comprise several pericyclic-type reactions. The geometrical and electronic analysis of the HF/6-31G∗ transition structures and intermediates allows characterizing the processes that take place along these domino reactions. B3LYP/6-31G∗ energetic results are in agreement with the experimental outcomes.

Generation of diazo-2-methylenecyclopropane and its 1,3-dipolar cycloaddition to acrylates

N-(2-Methylenecyclopropyl)-N-nitrosourea (2) was synthesized for the first time (yield 70%) and its decomposition induced by bases was studied. In particular, treatment with MeONa/MeOH at-30°C in the presence of methyl methacrylate gives the corresponding I-pyrazoline stereoisomers, the products of [3+2]-cycloaddition of diazo-2-methylene-cyclopropane (1) generatedin situ. Decomposition of2 on treatment with K2CO3 at 0–5°C in the presence of acrylonitrile also proceeds as [3+2]-cycloaddition: however, the expected 2-pyrazoline easily isomerizes into 5(3)-isopropenyl-3(5)-cyanopyrazole. Buta1,2,3-triene is the main product of base-induced decomosition of2 in the absence of unsaturated substrates.

Biodegradation of cyanide compounds by aPseudomonasspecies (S1)

A Pseudomonas sp. (S1), isolated from soil by an enrichment technique was tested for its potential to degrade different cyanide compounds. Further, biodegradation/biotransformation of binary mixtures of the cyanide compounds by the culture was also studied. The results indicated that the culture could grow on the following nitriles by using them as carbon and nitrogen sources: acetonitrile, butyronitrile, acrylonitrile, adiponitrile, benzonitrile, glutaronitrile, phenylacetonitrile, and succinonitrile. Studies on the biodegradation of these cyanide compounds in binary mixtures showed that the presence of acrylonitrile or KCN delayed the degradation of acetonitrile in a mixture, while none of the other cyanide compounds affected the degradation of one another. The transformation products of the nitriles were their corresponding acids, and similarly, KCN was also directly transformed to formic acid. Studies on the transformation of these cyanide compounds showed that the rate of transformation of nitriles to their corresponding carboxylic acids was acrylonitrile > acetonitrile > adiponitrile > benzonitrile > KCN. This culture has the unique characteristic of transforming representatives of saturated aliphatic, aliphatic olefinic, aromatic, and aralkyl nitriles, as well as alkali cyanide, to their corresponding carboxylic acids.

Biodegradation of cyanide compounds by a <i>Pseudomonas </i>species (S1)

A Pseudomonas sp. (S1), isolated from soil by an enrichment technique was tested for its potential to degrade different cyanide compounds. Further, biodegradation/biotransformation of binary mixtures of the cyanide compounds by the culture was also studied. The results indicated that the culture could grow on the following nitriles by using them as carbon and nitrogen sources: acetonitrile, butyronitrile, acrylonitrile, adiponitrile, benzonitrile, glutaronitrile, phenylacetonitrile, and succinonitrile. Studies on the biodegradation of these cyanide compounds in binary mixtures showed that the presence of acrylonitrile or KCN delayed the degradation of acetonitrile in a mixture, while none of the other cyanide compounds affected the degradation of one another. The transformation products of the nitriles were their corresponding acids, and similarly, KCN was also directly transformed to formic acid. Studies on the transformation of these cyanide compounds showed that the rate of transformation of nitriles to their corresponding carboxylic acids was acrylonitrile > acetonitrile > adiponitrile > benzonitrile > KCN. This culture has the unique characteristic of transforming representatives of saturated aliphatic, aliphatic olefinic, aromatic, and aralkyl nitriles, as well as alkali cyanide, to their corresponding carboxylic acids.

Ingold−Fischer “Persistent Radical Effect”, Solvent Effect, and Metal Salt Oxidation of Carbon-Centered Radicals in the Synthesis of Mixed Peroxides from tert-Butyl Hydroperoxide

Mixed peroxides are formed from tert-butyl hydroperoxide (TBH), tert-butyl peroxalate (TBP), and a variety of substrates (p-cresol, cyclohexene, styrene, α-methylstyrene, acrylonitrile, 2-methylcyclohexanone). Also, the oxidation of THF in the presence of acrylonitrile under the same conditions gives the mixed peroxide, generated by addition of the tetrahydrofuranyl radical to the double bond and the cross-coupling of the radical adduct with the tert-butylperoxyl radical. Similarly, benzoyl peroxide, TBH, and acrylonitrile give the mixed peroxide by oxidative arylation of the double bond. Paradoxically, TBH acts as effective inhibitor of the polymerization of vinyl monomers (acrylonitrile, styrene). An overall kinetic evaluation suggests that the conditions for the Ingold−Fischer “persistent radical effect”, characterized by the simultaneous formation of a persistent and a transient radical, are fulfilled in all cases. The reactions are strongly affected by solvents, which form hydrogen bonds with TBH. Ca...

Electrochemical trifluoromethylation of acrylonitrile and crotonitrile. Preparation of 2,3-bis(2,2,2-trifluoroethyl)succinonitrile and 3,4-dicyano-2,5-bis(trifluoromethyl)-n-hexane

Electrooxidation of trifluoroacetic acid in the presence of acrylonitrile in an acetonitrile-water solution, followed by simple steam distillation of the reaction mixture, provided almost pure 2,3-bis(2,2,2-trifluoroethyl)succinonitrile in a 20 – 25% yield and in a 1 : 1 diastereoisomers ratio. The meso isomer has been isolated and its structure confirmed by X-ray analysis. Similarly, the reaction in the presence of crotonitrile gave a diastereoisomeric mixture of 3,4-dicyano-2,5-bis(trifluoromethyl)-n-hexanes albeit in lower yield.

Embryotoxicity of acrylonitrile in whole-embryo culture

Day 10 rat embryos were cultured in rat serum for 26 hr in the presence of acrylonitrile at concentrations ranging from 76 to 760 μ m. Survival was not affected at any concentration tested. Normal development was observed at 76 μ m. Acrylonitrile induced concentration-related decreases in growth parameters (yolk-sac diameter, crown-rump length, head length, number of somite pairs), which were statistically significant at concentrations of 304 μ m or above. An acrylonitrile concentration of 152 μ m induced a significant increase in the incidence of malformations, which rose by 100% at 304 μ m. Malformations mainly consisted of a reduction of the brain and a shortened caudal extremity. The presence of 0.1–2.2 m m-reduced glutathione in the culture medium moderated the embryotoxic effects of 304 μ m-acrylonitrile in a concentration-related manner. Growth retardation and severity of malformations induced by 304 μ m-acrylonitrile were significantly increased by the addition of a hepatic microsomal preparation (S-9, microsomes) and cofactors for cytochrome P-450-dependent biotransformation (NADPH, glucose-6-phosphate) to the culture medium. Our results show that embryotoxicity of acrylonitrile does not require extra-embryonic biotransformation. However, the enhancement by exogenous cytochrome P-450-dependent monooxygenase systems supports a role for oxidative biotransformation in acrylonitrile embryotoxicity.

Glycosylidene Carbenes. Part 4. Synthesis of Spirocyclopropanes from Acetamidoglycosylidene‐Derived Diazirines

AbstractThe synthesis of the first glycosylidene‐derived 2‐acetamido‐2‐deoxydiazirine 4 from N‐acetylglucosamine 6 is described. Thus, 6 was transformed into the 3‐O‐mesylglucopyranoside 9 by glycosidation with allyl alcohol, benzylidenation, and mesylation (Scheme 2). Solvolysis of 9 gave the allopyranoside 10 which, upon benzylation and glycoside cleavage, yielded the hemiacetals 12. Using our established method (via the lactone oxime 14 and the diaziridines 16), 12 gave the diazirine 4. Thermolysis of this diazirine in the presence of i‐PrOH gave the dihydro‐1,3‐oxazole 5 (Scheme 1); in the presence of acrylonitrile, the four diastereoisomeric spirocyclopropanes 17–20 and the acetamidoallal 21 were obtained and separated by prep. HPLC (Scheme 3). Assignment of the configuration of 17–20 is based on NOE measurements and on the effect of diamagnetic anisotropy of the CN group. The ratio of the four cyclopropanes, which is in keeping with earlier results, is rationalized.

Structural Identification of Substituted C-1 Spiro Cyclopropyl Sugars.

ABSTRACT Photolysis of peracetylated D-glucopyranosylidene diazide in the presence of acrylonitrile in excess leads to new isomeric spiro C-1 cyclopropanic sugars (65% combined yield). Such structures, thus readily accessible by a new route which probably involves the addition of carbenic intermediates to an electrophilic alkene, have been identified by NMR investigations. In particular, the 1H NMR spectra show that the location and the orientation of the cyano substituent on the cyclopropyl ring can be easily established by way of the deshielding effect (0.2 - 0.3 ppm) which is induced on a sugar ring proton attached at C-2, C-3 or C-5. In order to unambiguously identify the obtained spirosugars, the crystal structure of one of them was determined by X-ray analysis. C17H21NO9, orthorhombic P212121, a=9.093(1), b=9.933(1), c=21.588(3) Å, Z=4, R=0.041 for 1645 unique observed reflexions.

ChemInform Abstract: Biomimetic Radical Cyclizations: Synthesis and Biosynthesis of Benzodihydropyrans and ‐furans.

AbstractThe thiohydroxamate (I) is irradiated in the presence of acrylonitrile (II), tributylstannane, and AIBN to produce the cyanopropylphenol ether (III).

Radiation‐initiated graft copolymerization of individual monomer and comonomer onto polyethylene and polytetrafluoroethylene films

AbstractPreparation and some properties of the graft copolymers obtained by radiation‐induced graft polymerization of methacrylic acid (MAA) and (acrylonitrile/MAA) comonomer onto polyethylene and polytetrafluoroethylene films, were investigated. The effect of reaction conditions, solvent, monomer, and inhibitor concentration, comonomer composition, and comonomer concentration, on the graft copolymerization process was studied. The grafting process was enhanced in the presence of comonomer (AN/MAA) as compared with individual grafting of MAA or acrylonitrile (AN). The optimum comonomer composition, at which the highest grafting yield was obtained, was found to be (80/20) wt % of (AN/MAA) comonomer. The graft copolymerization of (AN/MAA) comonomer was enhanced in presence of AN due to its higher polarity strength. The electrical and swelling properties of the graft copolymers were greatly affected by the contents of PAN and PMAA graft chains. Mechanical properties of the graft copolymers were significantly changed with the grafting yield.

Synthesis of C-1 spirocyclopropyl sugars from anomeric diazides.

The photolysis of peracetylated glucopyranosylidene diazide in the presence of acrylonitrile in excess yields four C-1 spirocyclopropyl sugars in a 65% combined yield. This unprecedented synthesis of bis C,C-glycosides is supposed to inlvolve anomeric carbene intermediates.