A-Phenylacrylonitrile

POLYMETHACRYLONITRILE, POLY-a-PHENYLACRYLONITRILE, POLY-a-CHLOROACRYLONITRILE AND POLYVINYLIDENE CYANIDE [141]... 

The behaviour of pure poly-a-phenylacrylonitrile is similar to that of polymethacrylonitrile. A strong exotherm which suggests a rapid cycliz-ation is nevertheless observed in the presence of 9% KCN as additive. 

The final product of this reaction is 2-amino-4-phenylpyrimidine. I5N-Labeling showed that the net substitution takes place by the ANRORC mechanism rather than by an AE process. The related sequence is shown in Scheme 2. Isolation of 3-amino-3-phenylacrylonitrile (39) in low yields at -75°C suggests that a parallel pathway via adduct 37 is also possible. However, the latter has not been detected in the reaction mixture. 

Reactivities of Side-chains of Monocyclic Thiophens.—The protonation of various furan- and thiophen-carboxamides in aqueous sulphur acid solution has been investigated by u.v. spectroscopy. The values of pKbh that were calculated using the acidity function and the Bunnett-Olsen linear free-energy relationship indicate the lower basicity of furan- and thiophen-2-carboxamides with respect to that of benzamides and of the 3-derivatives. The kinetics of isomerization of cw-l-(2-thienyl)-2-phenylacrylonitrile, as well as of its 2-furyl and 2-selenienyl analogues, have been studied in a solution of decahydronaph-thalene, with methanesulphonic acid and potassium t-butoxide as catalysts, and the mechanism has been discussed. ... 

Triazine 2-imines 18d-g are available from 4,6-disubstituted-l,2,3-triazines with 0-(mesitylenesulfonyl)hy-droxylamine (MSH) followed by treatment with potassium carbonate solution (Equation 19) <1988YZ1056>. N-2 Amination failed for monosubstituted 1,2,3-triazines 86a and 86b using both MSH and hydroxylamine-O-sulfonic acid (HOS). In the latter two cases, ring degradation by base occurred and only the 3-amino-2(3)-phenylacrylonitriles 98a and 98b were isolated as products, presumably via action of base on the intermediates 97. Lack of a substituent at C-6 of 86a and 86b was regarded as responsible for this failure <2004EJO4234> (Equation 20). 

Catalytic reduction of the o-(o-nitroaryl)acrylonitriles (Xl-84) over a palladium catalyst at room temperature gave the amine (XI-8S). Reduction with iron in boiling acetic acid yielded the indole XI-83, however. In an earlier work by Walker, catalytic (palladium, 80°) reduction of the corresponding -phenylacrylonitriles (XI-86) caused reductive cyclization of the nitrile to give the indole XI-87. An attempt was made to apply Walker s method to the 2-pyridyl isomer of XI-84 but the expected indole was not isolated. The mechanism proposed for the cyclization of XI-84 to the indole (XI-83 Py = 2-Pyridyl) involves an intramolecular Michael addition of a hydroxylamino group to the double bond rather than attack by an amino group. Support for... 

Reaction mixture heated at 100 °C for 6 h to afford ( -2-formyl-3-phenylacrylonitrile (162) (42.0 mg, 49 % formed as an inseparable 3.5 1 mixture with trani-cinnamaldehyde) as a pale yellow oil. 

Bis(trimethysilyl)methane derivatives react with aldehydes and ketones in the presence of a fluoride ion to afford di- and trisubstituted alkenes in one pot [56]. The reaction involves the fluoride-catalyzed carbonyl addition followed by Peterson elimination. For example, a,a-bis(trimethylsilyl)acetonitrile 153 produces /3-phenylacrylonitrile 154 with high -selectivity, whereas tris(trimethylsilyl)-methane 155 reacts with anisaldehyde at room temperature to give alkenylsilane 156 (Scheme 5.39). 

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