Vinyl acetate

About: Vinyl acetate is a research topic. Over the lifetime, 15970 publications have been published within this topic receiving 162142 citations. The topic is also known as: Ethenyl acetate & Ethenyl ethanoate.

Lipase catalyzed kinetic resolution of (±)-1-(1-naphthyl) ethanol under microwave irradiation

Abstract: 1-(1-Naphthyl) ethanol is an important chiral building block for the synthesis of active pharmaceutical intermediates (APIs). In this work, lipase catalyzed kinetic resolution of ( RS )-1-(1-naphthyl) ethanol via transesterification was studied under microwave irradiation with different acyl donors. Vinyl acetate was the most effective and hence used as the acyl donor. Three different commercially available immobilized lipases were used, among which Candida antarctica lipase B, immobilized on acrylic resin (Novozym 435) was found to be the best catalyst in n-heptane as solvent. The effect of various parameters was studied in a systematic manner. The reaction was intrinsically kinetically controlled. Maximum conversion of 47.74% with enantiometric excess of substrate ( ee s ) of 90.05% and enantiomeric ratio ( E ) of 433.39 was obtained in 3 h using 30 mg of enzyme loading with equi-molar ratio of alcohol to ester at 60 °C. From the progress curve analysis, the ping–pong bi–bi mechanism with inhibition by both substrates was found to fit the initial rates. Kinetic parameters were obtained by using non-linear regression. The process is efficient and easily scalable as compared to the chemical process.

Lipase-catalyzed resolution of racemic 2-alkyl substituted 1-alkanols

Abstract: R)-2-alkyl-1-alkanols (R)-1 with high optical purities were obtained by lipase-ca- talyzed esterification of the racemic substrates (Rs)-1 with vinyl acetate in dichloromethane. The alcohols (R)-1 were oxidized without racemization to the corresponding carboxylic acids (R)-4. The enriched Q-acetates (q-3 either were saponified to the alcohols (Q-1 which are substrates for a second lipase-catalyzed transesterification to give (Q-1 in high optical purity or were racemized and applied once again in the kinetic resolution to prepare (R)-1. Optically active 2-alkyl carboxylic acids as well as the corresponding primary alcohols are important intermediates in the synthesis of biologically active compounds and for the preparation of liquid crystals. (n-ZMethyl-1-hexanol and (Q-2-methyl-ldecanol, for example, have been used as chiral building blocks for the synthesis of the pheromones of the european pine saw fly3 and of the peach leaf miner moth.4 Q-2- Methyl pentanoic acid was used for the synthesis of (5')-4-methyl-3-heptanone, the pheromone of the leaf- cutting ant Atta texana.skb (&(+)-Manicone and (S')-(-)-normanicone, the mandibular gland constituents of myrmicine ants, were prepared starting from Q-Zmethyl-1-butano1.k For the preparation of chiral ferroelectric liquid crystals, 2-methyl-lcarboxylic acids and the corresponding primary alcohols were used in recent times.6

Biaxially oriented copolyester film primed with vinyl acetate polymers

Abstract: The invention concerns a primer coated, biaxially oriented self-supporting mono- or multilayer copolyester film, wherein the copolyester is PENBB and wherein the primer coating contains a vinyl acetate copolymer. PENBB is a copolyester containing units of formula (I).

Functionalized carbon nanotubes with oligomeric intumescent flame retardant for reducing the agglomeration and flammability of poly(ethylene vinyl acetate) nanocomposites

Abstract: A novel oligomeric phosphorous–nitrogen-containing intumescent flame retardant poly (2,6-diaminopyridine spirocyclic pentaerythritol bisphosphonate) (PDSPB) is synthesized, and subsequently multiwalled carbon nanotube (MWNT)-grafted oligomeric intumescent flame retardant, MWNT-g-PDSPB, is fabricated via chemical grafting reaction and characterized. The grafting reaction was characterized by FTIR, NMR, and XPS. After high-density PDSPB (88 wt%) were attached to the MWNTs, core-shell nanostructures with MWNTs as the hard core and PDSPB as the soft shell were formed. The resultant MWNT-g-PDSPB was soluble and stable in polar solvents, such as DMF and DMSO. MWNT-g-PDSPB has excellent thermal stability and charring ability. The TEM results showed that the functionalized MWNTs could achieve better dispersion in poly(ethylene vinyl acetate) (EVA) matrix. The residue char of MWNT-g-PDSPB is as high as 70 wt%, and the grafting of intumescent flame retardant of PDSPB can improve both the dispersion of MWNTs in polymer matrix and flame retardancy of the nanocomposites. POLYM. COMPOS., 2013. © 2012 Society of Plastics Engineers