Benzene acrylonitrile mixtures

Polyacrylonitrile is also quite insoluble in benzene, so that dilution of the monomer with benzene does not change the heterogeneous polymerization in any essential way. The effect of dilution on the specific surface is shown in Table III. There is a discernible trend toward lower surface areas at low acrylonitrile concentration. This is also evident in electron micrographs (Figure 2), where the particles from a benzene-acrylonitrile mixture are more compact and dense in appearance than those in Figure 1. Nevertheless, the surface is still extensive, and this has profound effects on the rate of polymerization. 

Figure 2. Particles from polymerization of 80/20 benzene acrylonitrile mixture at 50°C. AIBN concentration, 3 X 10 3M...

New copolymer membranes of acrylonitrile for the separation of benzene-CYH mixtures by PV were developed by Ray et al. (1997). The monomers in the copolymers were selected on the basis of their solubility parameter values relative to those of benzene and CYH. These were styrene, methyl methacrylate, and vinyl acetate. Copolymers of acrylonitrile with methyl methacrylate and vinyl acetate showed good selectivity and moderate flux 60-70 and 0.075 kg/m h, respectively, with a membrane of 10 pm thickness for a feed mixture containing 5% benzene. Copolymer of acrylonitrile with styrene showed comparatively higher flux but lower selectivity. Ray et al. claimed that the selectivities obtained with these membranes were better than those reported in the literature. 

Reaction with Acrylonitrile (9) As in the preceding case, a mixture of 61 g (0.45 mole) of aluminum chloride in 300 ml of benzene is heated to 60°, and a solution of 26.6 g (0.5 mole) of acrylonitrile in 100 ml of benzene is added. Butadiene (0.9 mole) is bubbled into the stirred and heated solution over a period of 4 hours, and the reaction mixture is worked up as above. Distillation gives 3-cyclohexene-1-carbonitrile, bp 80-87°/20 mm, nj,° 1.4742, in about 85% yield. 

Acetaldehyde, benzene, butyraldehyde, iso-prene, styrene, and toluene in mouse lymphocytes cell culture for 3 hours produced no effect on either viability or proliferation. Lormaldehyde, catechol, acrylonitrile, propionaldehyde, and hydroquinone significantly inhibited T-lymphocyte and B-lymphocyte proliferation, inhibitory concentration (IC )jo 1.19 x 10" M to 8.20 x 10" M. Acrolein and crotonaldehyde inhibited T-cell and B-cell proliferation and acted on viability with ICjp 2.06 x 10 M to 4.26 X 10" M. Mixtures of acrolein, formaldehyde, and propionaldehyde or crotonaldehyde interactive effects at 0.5 and 1 x ICjo were observed " . 

Job and Littlehailes [127] have irradiated a 1 1 molar mixture of benzene and acrylonitrile under nitrogen at 0°C and obtained 7-cyanobicyclo[4.2.0] octa-2,4-diene. The reaction did not proceed in the absence of ultraviolet irradiation or in a Pyrex apparatus. The yield of photoadduct is little affected by the presence of air, which, according to the authors, strongly supports the intermediacy of a singlet excited complex. They were, however, unable to detect a UV absorption band of a ground-state complex. However, the yields of adduct were low and the possibility is considered that a low-intensity absorption band is hidden by the benzene spectrum. 

Ohashi et al. [128] found that the yields of ortho photoaddition of acrylonitrile and methacrylonitrile to benzene and that of acrylonitrile to toluene are considerable increased when zinc(II) chloride is present in the solution. This was ascribed to increased electron affinity of (meth)acrylonitrile by complex formation with ZnCl2 and it confirmed the occurrence of charge transfer during ortho photocycloaddition. This was further explored by investigating solvent effects on ortho additions of acceptor olefins and donor arenes [136,139], Irradiation of anisole and acrylonitrile in acetonitrile at 254 nm yielded a mixture of stereoisomers of l-methoxy-8-cyanobicyclo[4.2.0]octa-2,4-diene as a major product. A similar reaction occurred in ethyl acetate. However, irradiation of a mixture of anisole and acrylonitrile in methanol under similar conditions gave the substitution products 4-methoxy-a-methylbenzeneacetonitrile (49%) and 2-methoxy-a-methylbenzeneacetonitrile (10%) solely (Scheme 43). 

Photocycloaddition of acrylonitrile in benzene gives a mixture of seven [2+2] cycloadducts, of which the three minor trans-fused components are rapidly isomerized. The major r-fused cyclobuta[ ]thiopyran products arise by head-to-tail addition which places the nitrile group at the 8-position. In the corresponding reaction with 2,3-dimethylbut-2-ene, the trans-iuscd adduct is the major product <2005HCA1922>. 

Table III. Specific Surface of Particles Formed in Polymerization of Acrylonitrile—Benzene Mixtures at 50°C.

Polymerization of acrylonitrile-benzene mixtures at 50 °C. resulted in a monomer exponent of about 1.7 in the rate expression. This is also in agreement with previous work (17, 20, 28, 31) on heterogeneous polymerization of acrylonitrile but not with homogeneous systems where a monomer exponent of unity is expected (4). 

To elucidate the nature of the product and confirm the postulated copolymerization, the reaction of isoprene and butadiene with acrylonitrile in the presence of zinc chloride was investigated. In the absence of solvent or in the presence of a small amount of benzene, the addition of a small amount of isoprene to an equimolar mixture of acrylonitrile and zine chloride results in spontaneous polymerization, and the solution turns orange. 

The addition of a mixture of monomers and catalyst to a suspension of zinc chloride in benzene or heptane gives 56 and 77% yield, respectively, of methanol-insoluble product containing ca. 57 mole % of acrylonitrile in both cases. Extraction of the product from the reaction carried out in heptane gave 8% of a DMF-soluble fraction which contained 90.9 mole % acrylonitrile and 92% of a DMF-insoluble fraction which contained 52.8% acrylonitrile, close to the theoretical value for an equimolar copolymer. In addition, the reaction mixture gave a 3.9% yield of a methanol-soluble fraction which contained 28.5 mole % acrylonitrile. 

Various mixtures of acrylonitrile and a-deuterioacrylonitrile with allene in benzene at 200 °C gave 3-cyanomethylenecyclobutane with deuterium content appropriate for k jk-Q == 1.00 0.02 7>. 

Similarly, the enamine of a 2-substituted cyclohexanone is alkylated by electrophilic alkenes such as acrylonitrile or methyl acrylate at the exposition in methanol or acetonitrile. However, prolonged reaction time (66 h) of the pyrrolidine enamine of 2-methylcyclohexanone with these reagents in dioxane or benzene under reflux gives a 1 1 mixture of 2,2- and 2,6-disubstituted cyclohexanones (38 and 39)82>83 (Scheme 23). 

Fig. 3. Conversion of styrene and acrylonitrile as function of time in different soF vents. Conditions as in Fjg. 2 (o) = benzene ( ) = toluene (o) = n-heptane ( ) = n-hep-tane-benzene (1 1 by wt) mixture ( ) = n-heptane-toluene mixture...

A solution of 10-diazoanthrone (2.2 g, 10 mmol) and acrylonitrile (2mL, 1.6 g, 30 mmol) in benzene (100 mL) was refluxed under N2 for 20 h, during which time the theoretical amount of N2 was evolved. After the mixture had been cooled to rt, concentrated in vacuo and filtered, 1.69 (65%) of cyclopropane crystallized from 95% EtOH as white needles mp 187-189"C. 

Acrylonitrile was also added to a mixture of benzene and macroradicals obtained from a monomer mixture containing equimolar amounts of maleic anhydride and styrene. Compared with the data already cited for styrene-rich macroradicals, only 50% of the macroradicals obtained from the equimolar mixture produced acetone-insoluble block copolymers. Since a mixture of maleic anhydride and acrylonitrile did not form a copolymer when heated with AIBN in benzene, it was concluded that half of these original macroradicals had maleic anhydride terminal groups. 

Radical cyclization reactions have found widespread use in the preparation of polyqui-nanes. A highly functionalized diquinane framework was prepared by Malacria and coworkers using a radical cascade process [66], It was anticipated that the (bromomethyl)-silyl ether 161 would serve as a suitable radical trigger. Thus, a solution of PhjSnH and AIBN was added over 5 h to a benzene solution of 161 and 10 equiv of acrylonitrile at reflux. Further heating for 5 h followed by Tamao oxidation of the crude product mixture allowed isolation of diquinane 162 in 51% yield as a single stereoisomer (by H-NMR) (Scheme 10-53). 

Copolymerization of 18 with styrene and acrylonitrile In the range of 40 to 60 mol % of the metallomonomer the copolymer composition does not depend on the monomeric mixture. The copolymers are soluble in benzene the molecular weights are about 10 Da. Under copolymerization conditions (75 °C, benzene, 1% of the initiator) of 18 with acrylonitrile (25 mol %) a light-yellow product containing -12% vanadium was obtained. The yield was 15%, the product is soluble in DMFA and DMSO, and its intrinsic viscosity was 0.11 (DMSO, 30 °C). IR 1720 (vc=o), 2245 cm (vc n) the ratio of the intensities of the absorptions /(C=0)//(C=N) = 13 1. This method can also be used for the synthesis and polymerization of optically active metallomonomers. 

The arene substrates are not limited to simple benzene derivatives. A variety of het-eroarenes can also participate in alkene arylations to generate the desired coupling products. Stoichiometric oxidative coupling of aromatic heterocycles such as furan, thiophene, selenophene, A-methylpyrrole, benzofiiran and benzothiophene with a variety of alkenes, including acrylonitrile, styrene and methyl acrylate, have been extensively studied by Fu-jiwara and coworkers [8]. Furan, thiophene, selenophene and A-methylpyrrole are easily alkenylated with alkenes to give 2-alkenylated and 2,5-dialkenylated heterocycles in relatively low yields (3 6%) [8a], while the reactions of benzofuran and benzothiophene with alkenes produced a mixture of 2- and 3-alkenylated products [8b]. 

De Haan, A. B. Boelts, R. Gmehling, J. Vapor-hquid eqmlibria and excess enthalpies for binary mixtures of acrylonitrile with hexane, cyclohexane, benzene, toluene, 2-butanone, and acetonitrile/. Chem. Eng. Data 1996,41, 1155-1159... 

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