Cyclohexane appears as a clear colorless liquid with a petroleum-like odor. Used to make nylon, as a solvent, paint remover, and to make other chemicals. Flash point -4°F. Density 6.5 lb / gal (less than water) and insoluble in water. Vapors heavier than air.
Four known or suspected metabolites of cyclohexane (cyclohexanol, cyclohexanone, 1,4-cyclohexanediol and 1,4-cyclohexanedione) were also studied for kidney effects. These compounds were administered at a daily dose of 0.5 g/kg (5 I.P. injections per week for two weeks). Only cyclohexanol increased beta-2-microglobulin which suggests that this metabolite is responsible for the kidney effects of cyclohexane.
The disposition and metabolism of cyclohexane have been investigated in three species; rat, rabbit and man. The available data indicate that cyclohexane can be absorbed via the oral and inhalation routes but no adequate data exist via the dermal route. There is no clear evidence of bioretention in the tissue examined. No cyclohexane was found in the brain of rats exposed to cyclohexane for 2 weeks. Cyclohexane is known to undergo oxidative metabolism to yield cyclohexanol (major metabolite), cyclohexanone, and possibly other oxidative products (1,2- or 1,4-dihydroxycyclohexane and its corresponding ketone analogs). The alcohol products can form phase 2 conjugates (sulfates and glucuronide).
The metabolism and toxicokinetics of cyclohexane (CH) and cyclohexanol (CH-ol), important solvents and chemical intermediates, were studied in volunteers after 8-hr periods of inhalation exposure at concentrations of 1010 and 236 mg/cu m, respectively (occupational exposure limits: CH, 1050 mg/cu m; CH-ol, 200 mg/cu m)). Of the dose of absorbed parent compounds, the yields of urinary CH-ol and 1,2- and 1,4-cyclohexanediol (CH-diol) were 0.5%, 23.4%, and 11.3%, respectively, after exposure to CH and 1.1%, 19.1%, and 8.4%, respectively, after exposure to CH-ol as determined by a gas chromatography method involving hydrolysis of glucuronide conjugates. The metabolic patterns of CH and CH-ol were very similar to that of cyclohexanone (CH-one) studied in the laboratory previously. For all three compounds, peak excretion of CH-ol occurred at the end of the exposure period, after which it decayed rapidly. Excretion curves of 1,2- and 1,4-CH-diol reached maximal values within 0-6 hr postexposure, with subsequent elimination half-lives being 14-18 hr. The rate-limiting step in the elimination of CH compounds from the organism is renal clearance of CH-diols...
IDENTIFICATION AND USE: Cyclohexane is a colorless, highly flammable liquid occurring naturally in petroleum at concentrations of 0.5-1.0%. It has a pungent petroleum-like odor and is used as an organic solvent for lacquers, resins, and synthetic rubber; paint and varnish remover; extraction of essential oils; manufacturing of solid fuel for camp stoves; in fungicidal formulations; in recrystallization of steroids; and in analytical chemistry for molecular weight determinations. It is also a chemical intermediate in the manufacturing of adipic acid, benzene, cyclohexyl chloride, nitrocyclohexane, cyclohexanol and cyclohexanone. Not registered for current pesticide use in the U.S., but approved pesticide uses may change periodically and so federal, state and local authorities must be consulted for currently approved uses. Studies from the exposure of the general population to cyclohexane revealed that human milk from five of eight mothers contained cyclohexane (concentrations not determined) from the mothers' exposure to environmental pollutants since they resided near chemical manufacturing plants or industrial user facilities. HUMAN EXPOSURE AND TOXICITY: The available data indicate that cyclohexane can be absorbed via oral and inhalation routes but no adequate data exist via the dermal route. Potential symptoms of overexposure to cyclohexane are irritation of eyes, skin and respiratory system; drowsiness; dermatitis; narcosis and coma although cyclohexane generally has low acute toxicity. In humans exposed via inhalation for 4 hours to 86 or 860 mg/cu m cyclohexane, there were no significant treatment-related effects. Occupational exposure to 5 to 211 ppm cyclohexane for a median of 1.2 years, had no adverse effects on the peripheral nervous system. There have been no systemic poisonings reported in man. Cyclohexane is known to undergo oxidative metabolism to yield cyclohexanol (major metabolite), cyclohexanone, and possibly other oxidative products (1,2- or 1,4-dihydroxycyclohexane and its corresponding ketone analogs). ANIMAL STUDIES: High vapor concentrations have produced convulsions in rabbits. Toxic oral doses in rabbits led to severe diarrhea, circulatory collapse and death, without prominent central nervous depression or anesthesia. Autopsy revealed generalized vascular damage but no effects on blood formation. Rats and mice, were exposed to 0, 500, 2000, or 7000 ppm of cyclohexane vapor 6 hr/day, 5 days/week for 14 weeks. During exposure sessions, mice exposed to 7000 ppm exhibited clinical signs of toxicity which included hyperactivity, circling, jumping/hopping, excessive grooming, kicking of rear legs, standing on front legs, and occasional flipping behavior. In another study, male and female mice exposed to 7000 ppm had slight increases in measures of circulating erythrocyte mass (red blood cells, hemoglobin, hematocrit) and plasma protein concentration (males only). Male rats and male and female mice exposed to 7000 ppm had significantly increased relative liver weights, and 7000 ppm male mice also had significantly increased absolute liver weights at the end of the exposure period. In the third study, female rats were administered cyclohexane intraperitoneally at a dose of 0.375, 0.75, or 1.5 g/kg, 5 days a week for 2 weeks. The high dose of 1.5 g/kg of cyclohexane caused a proximal tubular dysfunction of the kidney which resulted in an increase in beta-2-microglobulin. The increase in beta-2-microglobulin was attributed to the metabolite cyclohexanol. When testing the effect of cyclohexane on reproduction and development, there were statistically significant reductions in mean body weight, overall mean body weight gain, and overall mean food efficiency for P1 and F1 females exposed to 7000 ppm. Adult rats exposed to 2000 ppm or 7000 ppm cyclohexane exhibited diminished response or no response to a sound stimulus while in the chambers during exposure. Mean pup weight was statistically significantly reduced from lactation day 7 throughout the remainder of the 25-day lactation period for both F1 and F2 7000 ppm litters. Cyclohexane was negative for mutagenicity at doses of 0.01, 0.033, 0.10, 0.33, 1.0, 3.3, and 10 mg/plate in as many as 5 Salmonella typhimurium strains (TA1535, TA1537, TA97, TA98, and TA100) with or without metabolic activation. ECOTOXICITY STUDIES: Cyclohexane inhibited growth of Chlorella for 11-13 days, but prolonged the exponential growth phase and increased the growth yield 2.5 fold compared with the control. Acute toxicities after 24 and 96 hr exposures to seven alicyclic hexanes including cyclohexane were determined for striped bass and one of their major food organisms, the bay shrimp, Crangon franciscorum. The 96 hr LC50 for striped bass and bay shrimp ranged from 3.2 to 9.3 uL/L and from 1.0 to 6.2 uL/L, respectively.
Petroleum distillates are aspiration hazards and may cause pulmonary damage, central nervous system depression, and cardiac effects such as cardiac arrhythmias. They may also affect the blood, immune system, liver, and kidney. (A600, L1297)
来源:Toxin and Toxin Target Database (T3DB)
毒理性
暴露途径
该物质可以通过吸入其蒸汽和摄入进入人体。
The substance can be absorbed into the body by inhalation of its vapour and by ingestion.
来源:ILO-WHO International Chemical Safety Cards (ICSCs)
Studies from the exposure of the general population to cyclohexane revealed that human milk from five of eight mothers contained cyclohexane (concentrations not determined). /It was/ suggested that the cyclohexane in the milk resulted from the mothers' exposure to environmental pollutants since they resided near chemical manufacturing plants or industrial user facilities.
...Measures of brain metabolism, RNA, glutathione, and glutathione peroxidase activity were not affected by cyclohexane exposure. However, the cyclohexane dose increased, brain azoreductase activity decreased significantly and was still well below control levels after a recovery period. Activation of the mixed-function oxidase system has been found to inhibit azo reduction. /The results suggest/ that although increased blood circulation in the brain compared to fatty tissue enhances cyclohexane elimination from the brain, the activation of a liver mixed-function oxidase system is the primary vehicle for decreasing the cyclohexane concentration in the body as a whole.
Seventy-two hours after a single intravenous dose of 10 mg/kg [(14)C]cyclohexane or a single oral dose of 200 mg/kg to adult male Fischer 344 rats, the concentration of radioactivity in adipose was 16 times greater than that in blood. At higher oral doses (1,000 or 2,000 mg/kg), the adipose tissue-to-blood ratio of radioactivity approximately 45. Although radioactivity in adipose tissues was primarily cyclohexane (79-84%), in muscle, liver and skin, only 2-18% of the (14)C was identified as cyclohexane. Cyclohexane, cyclohexanol, and cyclohexanone were present in all tissues...
There are two major pathways in the elimination of cyclohexane: (1) cyclohexane (unmetabolized) is present in expired air, and (2) oxidative products e.g., cyclohexanol as free or bound, are present in the urine. Biomonitoring of cyclohexane exposure include the measurement of cyclohexane in alveolar air specimens or cyclohexanol (free or bound) in the urine.
<i>N</i>-Ammonium Ylide Mediators for Electrochemical C–H Oxidation
作者：Masato Saito、Yu Kawamata、Michael Meanwell、Rafael Navratil、Debora Chiodi、Ethan Carlson、Pengfei Hu、Longrui Chen、Sagar Udyavara、Cian Kingston、Mayank Tanwar、Sameer Tyagi、Bruce P. McKillican、Moses G. Gichinga、Michael A. Schmidt、Martin D. Eastgate、Massimiliano Lamberto、Chi He、Tianhua Tang、Christian A. Malapit、Matthew S. Sigman、Shelley D. Minteer、Matthew Neurock、Phil S. Baran
DOI：10.1021/jacs.1c03780
日期：2021.5.26
taking a first-principles approach guided by computation, these new mediators were identified and rapidly expanded into a library using ubiquitous buildingblocks and trivial synthesis techniques. The ylide-based approach to C–H oxidation exhibits tunable selectivity that is often exclusive to this class of oxidants and can be applied to real-world problems in the agricultural and pharmaceutical sectors
Facile Approach for C(sp3)–H Bond Thioetherification of Isochroman
作者：Chun Cai、Jie Feng、Guoping Lu、Meifang Lv
DOI：10.1055/s-0034-1380125
日期：——
An unprecedented C–S formation protocol via the direct oxidative C(sp3 )–H bond thioesterification of isochroman under metal-free conditions was developed. A series of isochroman derivatives could be afforded efficiently by the green, simple, and atom-economical method.
Heteroscorpionate ligands of the bis(pyrazolyl)methane family have been applied in the stabilisation of terminal copper tosyl nitrenes. These species are highly active intermediates in the copper‐catalysed direct C−H amination and nitrene transfer. Novel perfluoroalkyl‐pyrazolyl‐ and pyridinyl‐containing ligands were synthesized to coordinate to a reactive copper nitrene centre. Four distinct copper
Silica–Dendrimer Core–Shell Microspheres with Encapsulated Ultrasmall Palladium Nanoparticles: Efficient and Easily Recyclable Heterogeneous Nanocatalysts
作者：Ankush V. Biradar、Archana A. Biradar、Tewodros Asefa
DOI：10.1021/la203066d
日期：2011.12.6
We report the synthesis, characterization, and catalytic properties of novel monodisperse SiO2@Pd-PAMAM core–shell microspheres containing SiO2 microsphere cores and PAMAM dendrimer-encapsulated Pd nanoparticle (Pd-PAMAM) shells. First, SiO2 microspheres, which were prepared by the Stöber method, were functionalized with vinyl groups by grafting their surfaces with vinyltriethoxysilane (VTS). The vinyl
Nitrogen-enriched porous carbon supported Pd-nanoparticles as an efficient catalyst for the transfer hydrogenation of alkenes
作者：Jie Li、Xin Zhou、Ning-Zhao Shang、Cheng Feng、Shu-Tao Gao、Chun Wang
DOI：10.1039/c8nj03656j
日期：——
g-C3N4 as a nitrogen source and a self-sacrificial template. The prepared Pd@NPC exhibited superior catalytic activity and chemoselectivity for the catalytic transferhydrogenation of alkenes under mild conditions with formic acid as a hydrogen donor. Moreover, the catalyst displays high structure stability, and can be reused for five runs without any significant decrease of its catalytic activity and
将超细钯纳米颗粒固定在富氮多孔碳纳米片（NPC）上，该碳纳米片是用gC 3 N 4作为氮源和自牺牲模板制备的。所制得的Pd @ NPC在温和条件下，以甲酸为氢供体，对烯烃进行催化转移加氢显示出优异的催化活性和化学选择性。而且，该催化剂显示出高的结构稳定性，并且可以重复使用五次而不会显着降低其催化活性和明显的Pd浸出。这项工作提供了一种简便可行的方法来制造富氮碳纳米片，并构造高级钯负载的多相催化剂以实现高催化活性。
