Vinyl acetate appears as a clear colorless liquid. Flash point 18°F. Density 7.8 lb / gal. Slightly soluble in water. Vapors are heavier than air. Vapors irritate the eyes and respiratory system. May polymerize if heated or contaminated. If polymerization occurs inside a container, the container may violently rupture. Used to make adhesives, paints, and plastics.
颜色/状态:
COLORLESS, MOBILE LIQUID
气味:
An initially pleasant odor which quickly becomes sharp and irritating ... Not unpleasant , sweetish smell in small quantities
味道:
TASTELESS
蒸汽密度:
3 (EPA, 1998) (Relative to Air)
蒸汽压力:
90.2 mm Hg at 20 °C /extrapolated/
亨利常数:
Henry's Law constant = 5.11X10-4 atm-cu m/mol at 25 °C (est)
WHEN HEATED TO DECOMP, BURNS & EMITS FUMES WITH AN ACRID ODOR.
粘度:
0.43 cPs at 20 °C
燃烧热:
-9754 BTU/lb = -5419 cal/g = -226.9X10+5 J/kg
汽化热:
163 BTU/lb = 90.6 cal/g = 3.79X10+5 J/kg
表面张力:
23.95 DYNES/CM= 0.02395 N/M @ 20 °C
电离电位:
9.19 eV
聚合:
... TOO LOW A LEVEL OF INHIBITOR & WARM, MOIST STORAGE CONDITIONS MAY LEAD TO SPONTANEOUS POLYMERIZATION. THIS PROCESS INVOLVES AUTOOXIDATION OF ACETALDEHYDE ... TO PEROXIDE, WHICH INITIATES EXOTHERMIC POLYMERIZATION AS IT DCMP. ... OTHER PEROXIDES OR RADICAL SOURCES WILL INITIATE EXOTHERMIC POLYMERIZATION.
... /On/ hydrolysis /in the blood/, vinyl acetate yields acetic acid, a normal body constituent, and vinyl alcohol, which should rapidly tautomerize to yield acetaldehyde, another normal body constituent.
The hydrolysis of vinyl acetate was studied in vitro with rat liver and lung microsomes, rat and human plasma and purified esterases (acetylcholine esterase, butyrylcholine esterase, carboxyl esterase). Characterization of the kinetic parameters revealed that rat liver microsomes and purified carboxyl esterase (from porcine liver) displayed the highest activity. In order to establish the rate of metab of vinyl acetate in vivo, rats were exposed in closed desiccator jar chambers, and gas uptake kinetics were studied. The decay of vinyl acetate was dose-dependent, indicating possible satn of metabolic pathway(s). The maximal clearance (at lower concn) of vinyl acetate from the system (30,000 mL/hr/kg) was similar to the maximal ventilation rate in this species. The exposure of rats to vinyl acetate resulted in a transient exhalation of significant amts of acetaldehyde into the closed exposure system.
Gas chromatographic analysis of human whole-blood lymphocyte cultures treated for 10 seconds to 20 min with vinyl acetate (5.4 mM) revealed a rapid degradation of vinyl acetate and formation of acetaldehyde. During the 20 min observation period, no degradation of vinyl acetate or formation of acetaldehyde were observed in complete culture medium without blood, which suggested that the reaction was enzymatic.
Vinyl acetate hydrolysis has been studied in vitro in the oral mucosal tissues from the oral cavity of rats and mice. The hydrolysis activity of the oral tissues is at least 100-fold lower than that of the nasal tissues. A physiologically based pharmacokinetic model was developed which describes the deposition of vinyl acetate in the nasal cavity of the rat. This model predicts steady state concentrations of the metabolite acetic acid after continuing 6 hr-exposure in respiratory tissue which are approximately 13 times greater and in olfactory tissue which are approximately 2 times greater than those of acetaldehyde, the second metabolite. As the concentration of acids is indicative for the concentration of protons the model predicts the greatest reduction in intracellular pHi for respiratory mucosa. Hence, pH effects should be more pronounced in this tissue as compared to other tissues. This physiologically based toxicokinetic/toxicodynamic model for rat was modified for the olfactory epithelium of the both human and rat nasal cavity. The change in intracellular pH is predicted to be slightly greater for human olfactory epithelium, than that of rats. To provide validation data for this model, controlled human exposures at exposure levels of 1, 5 and 10 ppm to inhaled vinyl acetate were conducted. Air was sampled by a probe inserted into the nasopharyngeal cavity of five volunteers at bi-directional breathing through the nose. Data from ion trap mass spectrometry measurements of labeled vinyl acetate and acetaldehyde were compared with data from the human nasal model simulation. For the vinyl acetate data a good fit was demonstrated (r = 0.9).
Vinyl acetate may be absorbed following ingestion, inhalation, or dermal exposure, and distributes throughout the body. It is rapidly hydrolyzed by esterases in the blood to acetate and the unstable intermediate, vinyl alcohol. Vinyl alcohol is then rapidly converted to acetaldehyde, which in turn is metabolized to acetate in the liver. This in turn is incorporated into the "2 carbon pool" of normal body metabolism and eventually forms carbon dioxide as the major breakdown product, which is expired. (L1304)
Polyvinyl acetate usually contains trace amounts of its precursor, vinyl acetate. One of the metabolites of vinyl acetate, acetaldehyde, is a known animal carcinogen. Acetaldehyde can form adducts with DNA, causing damage such as cross-links. (L1304, A354)
One of the metabolites of vinyl acetate, acetaldehyde, is a known animal carcinogen. Acetaldehyde can form adducts with DNA, causing damage such as cross-links. (L1304, A354)
Evaluation: There is inadequate evidence in humans for the carcinogenicity of vinyl acetate. There is limited evidence in experimental animals for the carcinogenicity of vinyl acetate. Overall evaluation: Vinyl acetate is possibly carcinogenic to humans (Group 2B). In making the overall evaluation, the working group took into account the following evidence: (1) Vinyl acetate is rapidly transformed into acetaldehyde in human blood and animal tissues. (2) There is sufficient evidence in experimental animals for the carcinogenicity of acetaldehyde. Both vinyl acetate and acetaldehyde induce nasal cancer in rats after administration by inhalation. (3) Vinyl acetate and acetaldehyde are genotoxic in human cells in vitro and on animals in vivo.
来源:Hazardous Substances Data Bank (HSDB)
毒理性
致癌性证据
A3; 已确认的动物致癌物,对人类的相关性未知。
A3; Confirmed animal carcinogen with unknown relevance to humans.
来源:Hazardous Substances Data Bank (HSDB)
毒理性
致癌物分类
国际癌症研究机构致癌物:醋酸乙烯酯
IARC Carcinogenic Agent:Vinyl acetate
来源:International Agency for Research on Cancer (IARC)
... /The/ fate of inhaled vinyl acetate in rabbits /was studied/. ... Vinyl acetate tended to remain in the body after it was inhaled; 70% of the vinyl acetate administered was retained, and an equilibrium was established in the first few min after exposure began. ... No vinyl acetate /was found/ in the blood, either during or after its inhalation, which suggested ... that vinyl acetate is rapidly metabolized when it enters the body through the lungs.
When mice were exposed to (14)C-vinyl acetate, the radioactivity excretion pattern was similar to that observed with (14)C-acetaldehyde. In both cases, the majority of radioactivity was exhaled as (14)C-carbon dioxide.
Two male Wistar Rats exposed to vinyl acetate (stabilized with 0.01% hydroquinone) concentrations varying between 200 and 2000 ppm in closed chambers with an exposure time of 1.4 hr or less demonstrated dose dependent elimination kinetics. The authors concluded that the metabolic pathways became saturated when vinyl acetate exposure levels exceeded 650 ppm (2320 mg/cu m). Vinyl acetate deposition was measured in the isolated upper respiratory tract (URT) of anaesthetized adult male CrlCD:BR rats at exposure concentrations ranging from 73 to 2190 ppm during 1 hr inhalation under unidirectional flow conditions (flow rate 100 mL/min) ... Preliminary experiments showed that approximately 8 min of exposure was required for vinyl acetate to achieve a steady state in nasal tissues. After 8 min of equilibration, impinger samples were collected, approximately every 4 min, for up to 40 min and analyzed for vinyl acetate and acetaldehyde by gas chromatography ... Acetaldehyde was found in expired air at all vinyl acetate exposure concentrations. With increasing the vinyl acetate exposure, concentration of acetaldehyde in expired air increased. At vinyl acetate exposure of approximately 1000 ppm the concentration of acetaldehyde in the expired air was 277 ppm (499 mg/cu m).
Rats were administered oral doses of 14C-vinyl acetate (labeled at the vinyl moiety, 1 mL of a 10000 ppm (v/v) aqueous solution, overall dose level 297 mg/kg bw) by gastric intubation. The dosing regimen was 6 times 1 hour apart. During the dosing regime and subsequent 96 hr collection period, a mean of 64.4% of the administered radioactivity was excreted (1.4% in feces, 1.8% in urine and 61.2% in exhaled air). In addition a mean of 5.4% was found in the carcass at 96 hr. The major portion of the urinary radioactivity was excreted within the first 24 hr. Most of the radioactivity eliminated by the expired air was recovered during the 6 hr dosing regime and the first 6 hr after dosing. This portion of radioactivity was recovered from the traps designed for collecting carbon dioxide. The authors of the study suppose, that the unaccounted 30.1% of the dose were most likely lost in the expired air, which escaped from the metabolism cages when the animals were removed for dosing. There was a wide tissue distribution of radioactivity following administration of 14C-vinyl acetate by the oral route. One hour after the sixth dose the highest mean concentrations of radioactivity were found in the harderian gland and the submaxillary salivary gland. High levels were also found in the liver, kidney, stomach, ileum, colon and gastrointestinal tract contents. Low concentrations of radioactivity were found in fat. Attempts have been undertaken to determine vinyl acetate metabolites in urine and feces. No radiolabeled carbonates or bicarbonates were found in urine or feces. Thin layer chromatography of urine indicated that there was one major radioactive fraction and several minor fractions. Exhaled radioactivity was entirely present as 14C carbon dioxide. Therefore it can be concluded, that 63 % of orally applied 14C vinyl acetate is excreted as metabolites.
Enantiocontrolled synthesis of burseran, brassilignan, dehydroxycubebin, and other tetrahydrofuran lignans in both enantiomeric forms. Application of intermolecular nitrile oxide cycloadditions and lipase-mediated kinetic resolutions
摘要:
Several natural and unnatural tetrahydrofuran lignans have been synthesized by a convergent approach. Our methodology utilizes a nitrile oxide cycloaddition to dihydrofuran 8 and an enzymatic resolution of alcohols 11 by lipase PS. The lipase-mediated kinetic resolution of alcohols 11 furnished both enantiomers of the lignan precursors 12 and 14 in high optical purity (>99% ee). This is followed by a S(N)2 displacement of tosylates 15 and 18 by alpha-lithiobenzyl phenyl sulfides. In this manner, both enantiomers of 3,4-dibenzyltetrahydrofuran (17a, 20a), 3,4-bis(3-methoxybenzyl)-tetrahydrofuran (17b, 20b), brassilignan (17c, 20c), dehydroxycubebin (17d, 20d), and burseran (17e, 20e) were synthesized in overall yields of 6-16%.
Stereocontrolled Synthesis of Adjacent Acyclic Quaternary-Tertiary Motifs: Application to a Concise Total Synthesis of (−)-Filiformin
作者:Daniel J. Blair、Catherine J. Fletcher、Katherine M. P. Wheelhouse、Varinder K. Aggarwal
DOI:10.1002/anie.201400944
日期:2014.5.26
developed for the synthesis of acyclic quaternary‐tertiary motifs with full control of relative and absolute stereochemistry, thus leading to all four possible isomers of a stereodiad. A novel intramolecular Zweifel‐type olefination enabled acyclic stereocontrol to be transformed into cyclic stereocontrol. These key steps have been applied to the shortest enantioselective synthesis of (−)‐filiformin
Organic Syntheses on an Icosahedral Borane Surface: Closomer Structures with Twelvefold Functionality
作者:Tiejun Li、Satish S. Jalisatgi、Michael J. Bayer、Andreas Maderna、Saeed I. Khan、M. Frederick Hawthorne
DOI:10.1021/ja055226m
日期:2005.12.1
corresponding dianionic dodeca-ester closomers. The method using 1,1'-carbonyldiimidazole-activated carboxylic acids may be employed as a general synthetic strategy. The use of elevated reaction temperatures, achievable under pressure, to expedite syntheses is described. An attractive methodology using immobilized scavenger reagents for the expeditious purification of the closomer esters was employed. The developed
Catalytic Azido‐Hydrazination of Alkenes Enabled by Visible Light: Mechanistic Studies and Synthetic Applications
作者:Peng Wang、Yunxuan Luo、Songsong Zhu、Dengfu Lu、Yuefa Gong
DOI:10.1002/adsc.201901041
日期:2019.12.17
visible‐light‐enabled catalytic intermolecular azido‐hydrazination method for unactivated alkenes is developed via an orderly radical addition sequence. This transformation features metal‐free and redox‐neutral conditions and is applicable to a wide range of alkenes with commercially available reagents. Mechanistic and kinetic studies reveal that the efficient generation of azide radical enabled by fluorenone
Various C–C and C‐X bonds could be formed by doublefunctionalization of olefins featuring Cu‐mediated assistedtandemcatalysis. Furthermore, one‐pot indoline syntheses with o‐bromostyrenes as an application could be achieved.