Polymerization of 4-vinylbenzamides

Pogosyan, G. M.; Zhamkochyan, G. A.; Matsoyan, S. G.

doi:10.1016/0032-3950(65)90013-4

Cited by 3 publications

(4 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The preparation of p -vinylvalerophenone, 59 , was analogous to the preparation of p -cyclobutylvalerophenone, 27 . Thus reaction of 350 mg of p -bromostyrene in 7 mL of THF with 1.2 mL of 1.6 M n -butyllithium at −78 °C, followed by addition of 186 mg of valeraldehyde in 3 mL of ether, followed by oxidation with 625 mg of pyridinium chlorochromate in 8 mL of CH 2 Cl 2 , gave, after chromatography on 7 g of silica gel, 218 mg (61% yield) of 59 …”

Section: Methodsmentioning

confidence: 99%

Photochemical Behavior of Cyclopropyl-Substituted Benzophenones and Valerophenones

et al. 2011

View full text Add to dashboard Cite

p-Cyclopropylbenzophenone, 20, gives no photoreduction when irradiated in i-PrOH solvent. This is a general phenomenon and a number of cyclopropyl-substituted benzophenones, including 4-(endo-6-bicyclo[3.1.0]hexyl)benzophenone, 19, 4-(cis-2,3-dimethylcyclopropyl)benzophenone, 21, 4-(cis-2-vinylcyclopropyl)benzophenone, 22, and 4-(endo-7-bicyclo[4.1.0]hept-2-enyl)benzophenone, 23, also fail to undergo photoreduction. Instead these latter compounds undergo cis-trans isomerization when irradiated. A mechanism involving formation of an (n, π*) triplet, which subsequently fragments the strained cyclopropane bond to give a lower energy and unreactive open triplet, has been suggested. p-Cyclopropylvalerophenone, 25, and p-(endo-6-bicyclo[3.1.0]hexyl)valerophenone, 24, also undergo photoisomerization and fail to undergo the Norrish Type II photoreactions. Triplet energy dissipation by fragmentation of the cyclopropane bond is also proposed. In addition to the Norrish Type II reaction, p-cyclobutylvalerophenone, 27, undergoes a photofragmentation to give ethylene and p-vinylvalerophenone, 60, by an energy dissipation mechanism involving a 1,4-biradical derived from cyclobutane bond fragmentation.

show abstract

Section: Methodsmentioning

confidence: 99%

Photochemical Behavior of Cyclopropyl-Substituted Benzophenones and Valerophenones

et al. 2011

View full text Add to dashboard Cite

show abstract

“…After the solvent was removed by distillation in a rotary evaporator under reduced pressure, the product was distilled through a Claisen head fitted with a 10 em Vigreux column [bp 145-146°C (0.002mmHg)] and gave 9.1 g (53%) of a brown, viscous, 4-vinylbenzophenone. 14 The infrared spectrum (neat) showed absorptions at 1640 cm-1 (C=O stretching) and 980 and 905 em -1 (vinyl C-H out-of-plane bending). The 1 H NMR spectrum (CDC1 3 ) showed b 5.29-7.02 (vinyl protons, 3H) and 7.40-7.88 ppm (aromatic protons, 9H).…”

Section: Preparationsmentioning

confidence: 99%

Functional Polymers. VII. Ethyl 4-Vinyl-α-cyano-β-phenylcinnamate

Sumida

Vogl

1981

Polym J

View full text Add to dashboard Cite

ABSTRACT:Ethyl 4-vinyl-ct-cyano-/1-phenylcinnamate was prepared by a five step synthesis from 4-ethylbenzoic acid in an overall yield of 20%. The acid chloride of 4-ethylbenzoic acid was condensed with benzene to 4-ethylbenzophenone. The most critical step in the synthesis was the Knoevenagel condensation of 4-ethylbenzophenone with ethyl cyanoacetate which was accomplished with ammonium acetate as the catalyst. Ethyl 4-ethyl-ct-cyano-/1-phenylcinnamate was readily brominated with N-bromosuccinimide and the bromination product, ethyl 4-(1-bromoethyl)-ct-cyano-p-phenylcinnamate was dehydrobrominated. Ethyl 4-vinyl-ct-cyano-Pphenylcinnamate consists of a mixture of cis and trans isomers of nearly equal amounts as indicated in 1 H nuclear magnetic resonance and 13 C nuclear magnetic resonance spectroscopy. This new monomer was homopolymerized and copolymerized with styrene and methyl methacrylate with radical initiators.KEY WORDSPhoto-chemical reactions which occur in polymers on exposure to solar radiation cause damage to the physical and mechanical properties and to the appearance of polymers. When used outdoors, polymers are usually protected by adding ultraviolet (UV) stabilizers which can absorb most of the damaging radiation and reemit it in a form not harmful to the polymer. Low-molecular-weight UV absorbing compounds are used for the photo stabilization of polymers1. 2 with the most effective compounds being salicylates, 2,4-dihydroxybenzophenones, 2-hydroxyphenylbenzotriazoles or other more exotic, noncolor forming compounds. 3 • 4 More recently, interest in polymeric UV stabilizers has been directed towards the synthesis of vinyl substituted monomers which have groups capable of UV absorption. 3 .4 The successful synthesis of 3-vinyl, 5 4-vinyl, 6 and 5-vinylsalicylic acid derivatives 7 has been reported.The synthesis of 2,4-dihydroxy-4' -vinylbenzo- Polym. Sci., Polym. Chern. Ed., 18, 2755(1980. phenone, a powerful UV absorber, was accomplished in about a 14% overall yield from 4-ethylbenzoic acid. 8 · 9 The last three steps consisted of bromination of 2,4-diacetoxy-4' -ethylbenzophenone with N-bromosuccinimide followed by dehydrobromination and hydrolysis to 2,4-dihydroxy-4' -vinylbenzophenone. Esters of a-cyano-{3-phenylcinnamic acid have also been used in the past as UV stabilizers, 10 • 11 especially when UV absorbers with free phenolic groups were undesirable. Certain polymers, especially polyacetals, are sensitive to high concentrations of phenol containing UV stabilizers. At temperatures above 200°C where polyacetals are fabricated, ethyl a-cyano-{3-phenylcinnamate or the methyl ester have been found to have significant volatility and significant losses in stabilizer capacity. Consequently, attempts were made to decrease the volatility of a-cyano-{3-phenylcinnamates without diminishing their effectiveness by increasing their molecular weights 12 by preparing bisesters of glycols and a-cyano-{3-phenylcinnamic acid; the useful-521

show abstract

“…Therefore, 5 was replaced with 4Ј-(2-haloethyl)octanophenone. Even if 4Ј-(2-haloethyl)octanophenone affords the styrene 12 34) by elimination, it is expected that 12 will undergo Michael-type nucleophilic attack by the anion of the malonate 6 to give the intermediate 13. Further, the synthesis can be shortened, because 4Ј-(2-haloethyl)octanophenone can be derived from phenethyl halide, such as phenethyl bromide (10).…”

mentioning

confidence: 99%

“…At the same time, it was found that hydrogen iodide was eliminated from 9 to give the styrene 12 (equivalent to half the total amount of product), which was condensed with 6 to give 13 by Michael addition reaction. Next, the bromide 11 34) derived from 10 was examined. It was found that the elimination and condensation reactions could be run in one pot (see Experimental) to afford the key intermediate 13, which was hydrogenated to Adachi's intermediate, 7.…”

mentioning

confidence: 99%