Academic literature on the topic 'Chloro acetaldehyde'

The UV light-initiated reaction of chlorotrifluoroethylene with 1,2-ethanediol (I) proceeds only in the presence of acetone and affords 2-(2-chloro-1,1,2-trifluoroethyl)-2-methyl-1,3-dioxolane (VI). It has been proved that I is first photolyzed to acetaldehyde. Its acetalization in the reaction mixture gives 2-methyl-1,3-dioxolane (V) which then undergoes chlorotrifluoroethylation. The chlorotrifluoro derivative of 1,2-ethanediol XII was prepared by hydrolysis of 4-(2-chloro-1,1,2-trifluoroethyl)-2,2-dimethyl-1,3-dioxolane (XIII). 1,3-Propanediol (II) reacted to give 5-chloro-4,4,5-trifluoro-1,3-pentanediol (XVI). Analogous reaction of 1,4-butanediol (III) and 1,3-butanediol (IV) afforded, in addition to derivatives with chlorotrifluoroethyl group at the hydroxyl-bearing carbon atom (XVII from III, XIX and XX from IV), also the respective bis-chlorotrifluoroethyl derivatives XVIII and XXI as products arising by the 1,5- or 1,6-transfer in the radical intermediates.

The gas-phase reaction between trans-2-methyl-2-butenal and chlorine (Cl) atoms has been studied in a simulation chamber at 298 ± 2 K and 760 ± 5 Torr of air under free-NOx conditions. The rate coefficient of this reaction was determined as k = (2.45 ± 0.32) × 10−10 cm3 molecule−1 s−1 by using a relative method and Fourier transform infrared spectroscopy. In addition to this technique, gas chromatography coupled to mass spectrometry and proton transfer time-of-flight mass spectrometry were used to detect and monitor the time evolution of the gas-phase reaction products. The major primary reaction product from the addition of Cl to the C-3 of trans-2-methyl-2-butenal was 3-chloro-2-butanone, with a molar yield (YProd) of (52.5 ± 7.3)%. Acetaldehyde (Y = (40.8 ± 0.6)%) and HCl were also identified, indicating that the H-abstraction by Cl from the aldehyde group is a reaction pathway as well. Secondary organic aerosol (SOA) formation was investigated by using a fast mobility particle sizer spectrometer. The SOA yield in the Cl + trans-2-methyl-2-butenal reaction is reported to be lower than 2.4%, thus its impact can be considered negligible. The atmospheric importance of the titled reaction is similar to the corresponding OH reaction in areas with high Cl concentration.

Mercury (Hg) emissions from anthropogenic sources pose a global problem. In Central Asia, Kazakhstan’s central and northern regions are among the most severely Hg-contaminated territories. This is due to two former acetaldehyde (in Temirtau) and chlor-alkali (in Pavlodar) plants, discharges from which during the second half of the 20th century were estimated over 2000 tons of elemental Hg. However, the exact quantities of Hg released through atmospheric emissions to the environment, controlled discharges to the nearby aquatic systems, leakages in the cell plant, and contaminated sludge are still unknown. The present review is the initiation of a comprehensive field investigation study on the current state of these contaminated sites. It aims to provide a critical review of published literature on Hg in soils, sediments, water, and biota of the impacted ecosystems (Nura and Irtysh rivers, and Lake Balkyldak and their surrounding areas). It furthermore compares these contamination episodes with selected similar international cases as well as reviews and recommends demercuration efforts. The findings indicate that the contamination around the acetaldehyde plant site was significant and mainly localized with the majority of Hg deposited in topsoils and riverbanks within 25 km from the discharge point. In the chlor-alkali plant site, Lake Balkyldak in North Kazakhstan is the most seriously contaminated receptor. The local population of both regions might still be exposed to Hg due to fish consumption illegally caught from local rivers and reservoirs. Since the present field data is limited mainly to investigations conducted before 2010 and given the persisting contamination and nature of Hg, a recent up-to-date environmental assessment for both sites is highly needed, particularly around formerly detected hotspots. Due to incomplete site remediation efforts, recommendations given by several researchers for the territories of the former chlor-alkali and acetaldehyde plant site include ex-situ soil washing, soil pulping with gravitational separation, ultrasound and transgenic algae for sediments, and electrokinetic recovery for the former and removal and/or confinement of contaminated silt deposits and soils for the latter. However, their efficiency first needs to be validated. Findings and lessons from these sites will be useful not only on the local scale but also are valuable resources for the assessment and management of similar contaminated sites around the globe.

The induction of aneuploidy by physical and chemical agents using different test systems was evaluated. The effect of X-rays, caffeine, acetaldehyde, ethanol, diethylstilbestrol, propionaldehyde, and chloral hydrate was studied by chromosome counting in Chinese hamster embryonic diploid cells. Aneugenic ability of cadmium chloride, cadmium sulfate, potassium dichromate, chromium chloride, nickel chloride, and nickel sulfate was assessed by means of anaphase-telophase analysis in Chinese hamster ovary cells. Chromosome counting in human fibroblasts (MRC-5 cell line) was employed to evaluate the effect of cacodilic acid, cadmium chloride, cadmium sulfate, and potassium dichromate. Finally, the induction of kinetochore-positive and kinetochore negative micronuclei by cadmium chloride, cadmium sulfate, potassium dichromate, chromium chloride, and nickel chloride was studied using CREST antibodies. When the effect of different agents was determined by chromosome counting, an increase of hypoploid but not of hyperploid cells was observed. Anaphase-telophase analysis showed that metal salts increased the frequency of lagging chromosomes. This finding has been confirmed by the increment of kinetochore-positive micronuclei using CREST antibodies. Therefore, chromosome loss could be considered as the main cause of induced aneuploidy.

Le polymorphisme de l'adn et les distorsions induites par la fixation d'un agent antitumoral: le cis-ddp sont etudies a l'aide de reactifs specifiques de la nature et de la conformation des bases. Le bromo ou chloroacetaldehyde permet de cartographier les adenines et les cytosines d'une sequence en conformation z et des jonctions adn-b-adn-z. La caracterisation des distorsions induites par le cis-ddp sur des oligonucleotides et sur les fragments d'adn a ete realisee a l'aide de sondes chimiques. L'accessibilite de la thymine complementaire de l'adenine d'un adduit d(apg) depend de la sequence environnante, la cytosine complementaire n'est pas accessible

La condensation du lithio-1 triméthylsiloxy-2 éthylène avec les chlorotrialkylsilanes et le triflate de t-butyldiméthylsilyle conduit aux éthers d'énols silyles -silyles. L'hydrolyse acide de ces derniers permet d'isoler le t-butyldiméthylsilyl acétaldéhyde. D'autre part, la condensation du lithio-1 triméthylsiloxy-2 éthylène avec les chlorures d'acides non énolisables conduit a des esters d'énols de -cétoaldéhydes