A study was conducted to establish whether volatile hydrocarbons, such as propane, n-butane and iso-butane, are metabolized in mice or not. In mice having inhaled these gases, isopropanol and acetone were yielded from propane, sec-butanol and methyl ethyl ketone from n-butane, and tert-butanol from iso-butane as the respective metabolites. In addition, liver microsomes were found to contain the enzymic system participating in these metabolisms. In vitro reactions with liver microsomes produced isopropanol from propane, sec-butanol from n-butane, and tert-butanol from iso-butane. It was assumed that hydrocarbons were first converted to (omega-1)-alcohols by microsomal enzyme system and then to corresponding ketones by alcohol dehydrogenase.
IDENTIFICATION AND USE: Isobutane is a colorless gas. It is used in organic synthesis, as a refrigerant, in motor fuels, and as aerosol propellant, as well as in synthetic rubber, and in instrument calibration fluid. HUMAN STUDIES: Isobutane is a simple asphyxiant. Acute exposure may cause tachypnea and tachycardia. In severe cases, hypotension, apnea, and cardiac arrest develop. Direct contact with the liquid produces chemical burns. Toxicologically, the vapor exerts no effect on skin and eyes. A case of ventricular fibrillation due to isobutane toxicity after unintentional inhalation of air freshener has been reported. The intentional inhalation of a volatile substance ("sniffing") causing euphoria and hallucinations is a form of substance abuse in children and adolescents with a high morbidity and mortality. Sudden death can be caused by cardiac arrhythmia, asphyxia or trauma. Fatal cases of isobutane sniffing of cigarette lighter refill containing isobutane has been reported. ANIMAL STUDIES: Studies in rabbits exposed through the eyes to undiluted hairspray containing 22% isobutane showed that irritation of the eye was immediately evident with transient iritis and mild conjunctivitis. Acute exposure in dogs to 55 mg/L isobutane was fatal, and 45 mg/L caused anesthesia. Two-hour exposures of mice to 41 mg/L isobutane caused death in 60% of the exposed animals, whereas exposure to 52 mg/L was lethal to 100% of the animals within an average of 28 min. Isobutane is a CNS depressant in the mouse at 15% in 60 min, and at 23% in 26 min. Isobutane caused apnea and finally cardiac arrest in anesthetized rats. Isobutane tested negative in the Ames Salmonella mutagenicity assay.
Butane is a simple asphyxiant and causes toxicity by displacing oxygen. It also affects the central nervous system by enhancing glycine receptors and inhibiting nicotinic acetylcholine and N-methyl-d-aspartate (NMDA) receptors, resulting in anesthetic effects. (L1284, A352)
来源:Toxin and Toxin Target Database (T3DB)
毒理性
致癌物分类
对人类不具有致癌性(未被国际癌症研究机构IARC列名)。
No indication of carcinogenicity to humans (not listed by IARC).
Butane targets the central nervous system and cardiovascular system. Inhalation of butane can cause frostbite which can result in death from asphyxiation and ventricular fibrillation. (L1283, L1284)
来源:Toxin and Toxin Target Database (T3DB)
毒理性
暴露途径
该物质可以通过吸入被身体吸收。
The substance can be absorbed into the body by inhalation.
来源:ILO-WHO International Chemical Safety Cards (ICSCs)
Hydride ion transfer reactions in the gas phase. Pressure dependence of reaction efficiency as a criterion for the recognition of anchimeric assistance
Gas-phase reactions of iron(1-) and cobalt(1-) with simple thiols, sulfides, and disulfides by Fourier-transform mass spectrometry
作者:L. Sallans、K. R. Lane、B. S. Freiser
DOI:10.1021/ja00185a013
日期:1989.2
products, H-Fesup minus}}-SH and Fesup minus}}-SH. Some of the thermochemical data derived from this study include Ddegree}(Msup minus}}-S) > 103 kcal/mol and Ddegree}(Msup minus}}-SH) = 83 plus minus}9 kcal/mol. Finally, a brief survey of the reactivity of Vsup minus}}, Crsup minus}}, and Mosup minus}} with selected organosulfur compounds is also reported. 79 refs., 3 figs., 7 tabs
Process for the preparation of optically active piperazine-2-carboxylic
申请人:Lonza, Ltd.
公开号:US05886181A1
公开(公告)日:1999-03-23
Optically active piperazine-2-carboxylic acid derivatives of the general formula: ##STR1## wherein R.sup.1 and R.sup.2 are inter alia hydrogen, alkyl or acyl and X is alkoxy or a (substituted) amino group, are prepared by asymmetric hydrogenation of the corresponding 1,4,5,6-tetrahydropyrazines, catalyzed by optically active rhodium, ruthenium or iridium complexes. The compounds of the Formula 1 are intermediates for the preparation of pharmaceutical active ingredients, for example, HIV protease inhibitors.
Palladium(0)-Catalyzed Cross-Coupling of 1,1-Diboronates with Vinyl Bromides and 1,1-Dibromoalkenes
作者:Huan Li、Zhikun Zhang、Xianghang Shangguan、Shan Huang、Jun Chen、Yan Zhang、Jianbo Wang
DOI:10.1002/anie.201407000
日期:2014.10.27
Palladium‐catalyzed cross‐coupling reactions of 1,1‐diboronates with vinylbromides and dibromoalkenes were found to afford 1,4‐dienes and allenes, respectively. These reactions utilize the high reactivities of both 1,1‐diboronates and allylboron intermediates generated in the initial coupling.
The dehydrogenation and isomerization of butane to isobuteneover Cr catalysts supported on zeolites were investigated. Although a zeolite support, especially with a low Si/Al 2 ratio, favors the cracking of butane over its dehydrogenation and isomerization, due to strong solid acidity, the loading of Cr on a zeolite support enhances the dehydrogenation and isomerization of butane. H-SSZ-35 type zeolite