Names | |
---|---|
IUPAC name (4-Methylcyclohexyl)methanol | |
Other names
| |
Identifiers | |
3D model (JSmol) | |
ChEBI | |
ChEMBL | |
ChemSpider | |
ECHA InfoCard | 100.131.091 |
EC Number |
|
PubChem CID | |
UNII | |
CompTox Dashboard (EPA) | |
| |
| |
Properties | |
C8H16O | |
Molar mass | 128.215 g·mol−1 |
Appearance | Colourless liquid |
Odor | mint-like, licorice-like (trans) |
Density | 0.9074 g/cm3 |
Boiling point | 202 °C (396 °F; 475 K) [1] |
low | |
Refractive index (nD) | 1.4617 [2] |
Hazards | |
GHS labelling: [3] | |
Warning | |
H315, H319, H335 | |
Flash point | 80 °C (176 °F; 353 K) |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
4-Methylcyclohexanemethanol (MCHM, systematic name 4-methylcyclohexylmethanol) is an organic compound with the formula CH3C6H10CH2OH. Classified as a saturated higher alicyclic primary alcohol. Both cis and trans isomers exist, depending on the relative positions of the methyl (CH3) and hydroxymethyl (CH2OH) groups on the cyclohexane ring. Commercial samples of MCHM consists of a mixture of these isomers as well as other components that vary with the supplier.
It is a colourless oil with a faint mint-like alcohol odor. [4] The trans isomer has a particularly low odor threshold (~7 ppb in water) and a more licorice-like quality which is not associated with the less detectable cis isomer. [5] [6] Like other 8-carbon alcohols, such as 1-octanol, this compound is only slightly soluble in water but highly soluble in many organic solvents. The solubility of 1-octanol in water is 2.3 grams per liter.
It was first prepared in 1908 by Bouveault–Blanc reduction of a methylcyclohexanecarboxylate ester. [4]
It is also produced as a byproduct (ca. 1%) in the production of cyclohexanedimethanol, a commodity chemical, during hydrogenation of dimethyl terephthalate. [7]
It has been patented for use in air fresheners. [8]
U.S. Patent 4915825 describes a froth flotation process for cleaning coal where a mixture of 95% MCHM, 4% water, and 0.1% 4-methylcyclohexanemethanol monoether (such as 4-(methoxymethyl)cyclohexanemethanol) is used as a frothing agent, and finely divided coal particles adhere to air bubbles induced into the agent which rise to the surface. Other cyclohexane-based alcohols can also be used. MCHM has the advantage of being less toxic than previous frothing agents containing 2-ethylhexanol. [9] The original patent owners let the patent expire after eight years for failure to pay maintenance fees. [10]
Reliable information on health and safety of this compound is limited. The ChemSpider entry for MCHM indicates that it has been evaluated for ligand activity via SimBioSys's LASSO analysis, which predicted low to no activity on 40 biologically significant receptors, indicating a low likelihood for significant biological activity on them. [11] Eastman Chemical Company's MSDS for "crude" (unpurified) MCHM, as supplied by NPR, reports an oral LD-50 of 825 mg/kg and a dermal LD-50 greater than 2,000 mg/kg, both in rats. [12] Further data from Eastman's internal studies was released after the Elk River, West Virginia (2014) spill, including the studies upon which the LD-50 estimate was based and one 28-day study of oral toxicity of pure MCHM which concluded that 400 mg/kg doses were associated with erythropoietic, liver, and kidney effects, though these were not considered more than "minor toxicity" and the "no observed effect" level was considered to be 100 mg/kg/day. [13]
A World Health Organization study of the toxicity of alicyclic primary alcohols and related alicyclic carbohydrates (of which MCHM is one type) found that LD-50 values for substances in this class generally "ranged from 890 to 5700 mg/kg bw for rats and > 1000 to 4000 mg/kg bw for mice, demonstrating that the oral acute toxicity of alicyclic primary alcohols, aldehydes, acids and related esters is low". [14] The same study indicated that these alcohols are metabolized primarily to corresponding carboxylic acids, which in the case of MCHM is 4-methylcyclohexanecarboxylic acid (CAS 13064–83–0), a naphthenic acid. The toxicity and environmental properties of these naphthenic acids have been well studied recently due to their occurrence as a major contaminant in water used for extraction of oil from tar sands. [15] Naphthenic acids have both acute and chronic toxicity to fish and other organisms. [15] The methyl ester of this acid is also listed as one of the major impurities in the "crude MCHM" as supplied by Eastman. [12]
The closely related compound cyclohexanedimethanol (CAS 105–08–8) exhibits low toxicity (3.5 g/kg) when fed orally to rats. [16]
Cyclohexanemethanol (or cyclohexylmethanol, CHM, CAS 100–49–2), another closely related compound, which differs only in lacking a methyl substituent, has been found as a naturally occurring fusel alcohol in mango wine at concentrations of 1.45 mg/L, in which it is considered an aroma constituent. [17] LASSO analysis predicts low to no activity on 40 receptors, similarly to MCHM. [18]
CHM with a methylethyl (or isopropyl) substituent group at the same position as the methyl group in 4-methylcyclohexanemethanol (cis-4-(1-methylethyl) cyclohexane methanol, CAS 13828–37–0) is regarded as a flavoring and fragrance agent, sometimes listed under the synonym p-menthan-7-ol, and was the subject of a review article on its toxicological and dermatological properties in 2008. [19] Among other findings, Bhatia et al. reported a 14-day oral toxicity study in rats with doses of 10.0 g/kg by gavage with no deaths or toxic effects observed, nor any abnormalities on necropsy. Dermal application of "neat" (pure, undiluted) cis-p-menthan-7-ol at 2 g/kg bodyweight produced toxic effects in rats and rabbits.
Various patch tests of cis-p-menthan-7-ol on human volunteers with concentrations of 10%, 15%, and 20% produced irritation in one instance, and a "questionable" reaction in another. These both occurred out of a group of 102 volunteers with a 15% concentration in diethyl phthalate and ethanol. However, a longer-term (six-week) repetition of that test as a sensitization study failed to produce any reactions. [19]
A WHO study concluded that p-menthan-7-ol was of "no safety concern" for human consumption at high levels of 2.5 μg/kg of bodyweight and for typical levels in Japan of 0.03 μg/day. [20]
Another CHM derivative, 2,4-dimethylcyclohexanemethanol (CAS 68480–15–9, also dihydrofloralol or floral methanol), which has two methyl substituents instead of one, is frequently marketed as a fragrance or flavor additive. One web site, Fantastic Flavours provides a list of recognized flavor additives for Japan, which includes 2,4-dimethylcyclohexanemethanol by virtue of being in the group of aliphatic higher alcohols. [21]
On 9 January 2014, approximately 10,000 US gal (38,000 L) of impure MCHM leaked from a storage tank near the banks of the Elk River near Charleston, West Virginia (U.S.), from where an undetermined amount entered the river and was taken into the local water system (1,272 gallons were reported recovered). [22] [23] [24] State and federal agencies declared a state of emergency and ordered over 300,000 residents in nine counties—one sixth of West Virginia's population—not to drink or use tap water for any purpose other than flushing toilets. [25] The external affairs manager of West Virginia American Water said that the spill originated with Freedom Industries, a Charleston company. [26]
Fumaric acid or trans-butenedioic acid is an organic compound with the formula HO2CCH=CHCO2H. A white solid, fumaric acid occurs widely in nature. It has a fruit-like taste and has been used as a food additive. Its E number is E297. The salts and esters are known as fumarates. Fumarate can also refer to the C
4H
2O2−
4 ion (in solution). Fumaric acid is the trans isomer of butenedioic acid, while maleic acid is the cis isomer.
Demeton-S-methyl is an organic compound with the molecular formula C6H15O3PS2. It was used as an organothiophosphate acaricide and organothiophosphate insecticide. It is flammable. With prolonged storage, Demeton-S-methyl becomes more toxic due to formation of a sulfonium derivative which has greater affinity to the human form of the acetylcholinesterase enzyme, and this may present a hazard in agricultural use.
2-Butoxyethanol is an organic compound with the chemical formula BuOC2H4OH. This colorless liquid has a sweet, ether-like odor, as it derives from the family of glycol ethers, and is a butyl ether of ethylene glycol. As a relatively nonvolatile, inexpensive solvent, it is used in many domestic and industrial products because of its properties as a surfactant. It is a known respiratory irritant and can be acutely toxic, but animal studies did not find it to be mutagenic, and no studies suggest it is a human carcinogen. A study of 13 classroom air contaminants conducted in Portugal reported a statistically significant association with increased rates of nasal obstruction and a positive association below the level of statistical significance with a higher risk of obese asthma and increased body mass index.
Isobutanol (IUPAC nomenclature: 2-methylpropan-1-ol) is an organic compound with the formula (CH3)2CHCH2OH (sometimes represented as i-BuOH). This colorless, flammable liquid with a characteristic smell is mainly used as a solvent either directly or as its esters. Its isomers are 1-butanol, 2-butanol, and tert-butanol, all of which are important industrially.
4-Methylaminorex is a stimulant drug of the 2-amino-5-aryloxazoline class that was first synthesized in 1960 by McNeil Laboratories. It is also known by its street name "U4Euh" ("Euphoria"). It is banned in many countries as a stimulant.
2-Ethylhexanol is an organic compound with the chemical formula CH3CH2CH2CH2CH(CH2CH3)CH2OH. It is a branched, eight-carbon chiral alcohol. It is a colorless liquid that is poorly soluble in water but soluble in most organic solvents. It is produced on a large scale (>2,000,000,000 kg/y) for use in numerous applications such as solvents, flavors, and fragrances and especially as a precursor for production of other chemicals such as emollients and plasticizers. It is encountered in plants, fruits, and wines. The odor has been reported as "heavy, earthy, and slightly floral" for the R enantiomer and "a light, sweet floral fragrance" for the S enantiomer.
1-Butanol, also known as butan-1-ol or n-butanol, is a primary alcohol with the chemical formula C4H9OH and a linear structure. Isomers of 1-butanol are isobutanol, butan-2-ol and tert-butanol. The unmodified term butanol usually refers to the straight chain isomer.
Crotonaldehyde is a chemical compound with the formula CH3CH=CHCHO. The compound is usually sold as a mixture of the E- and Z-isomers, which differ with respect to the relative position of the methyl and formyl groups. The E-isomer is more common (data given in Table is for the E-isomer). This lachrymatory liquid is moderately soluble in water and miscible in organic solvents. As an unsaturated aldehyde, crotonaldehyde is a versatile intermediate in organic synthesis. It occurs in a variety of foodstuffs, e.g. soybean oils.
Naphthenic acids (NAs) are mixtures of several cyclopentyl and cyclohexyl carboxylic acids with molecular weights of 120 to well over 700 atomic mass units. The main fractions are carboxylic acids with a carbon backbone of 9 to 20 carbons. McKee et al. claim that "naphthenic acids (NAs) are primarily cycloaliphatic carboxylic acids with 10 to 16 carbons", although acids containing up to 50 carbons have been identified in heavy petroleum.
Cyhalothrin is an organic compound that, in specific isomeric forms, is used as a pesticide. It is a pyrethroid, a class of synthetic insecticides that mimic the structure and properties of the naturally occurring insecticide pyrethrin which is present in the flowers of Chrysanthemum cinerariifolium. Pyrethroids, such as cyhalothrin, are often preferred as an active ingredient in agricultural insecticides because they are more cost-effective and longer acting than natural pyrethrins. λ-and γ-cyhalothrin are now used to control insects and spider mites in crops including cotton, cereals, potatoes and vegetables.
Dinoseb is a common industry name for 6-sec-butyl-2,4-dinitrophenol, a herbicide in the dinitrophenol family. It is a crystalline orange solid which does not readily dissolve in water. Dinoseb is banned as an herbicide in the European Union (EU) and the United States because of its toxicity.
Cyclohexanedimethanol (CHDM) is a mixture of isomeric organic compounds with formula C6H10(CH2OH)2. It is a colorless low-melting solid used in the production of polyester resins. Commercial samples consist of a mixture of cis and trans isomers. It is a di-substituted derivative of cyclohexane and is classified as a diol, meaning that it has two OH functional groups. Commercial CHDM typically has a cis/trans ratio of 30:70.
Imazaquin is an imidazolinone herbicide, so named because it contains an imidazolinone core. This organic compound is used to control a broad spectrum of weed species. It is a colorless or white solid, although commercial samples can appear brown or tan.
Decenoic acid is any mono-carboxylic acid with an unbranched chain of ten carbons connected by eight single bonds and one double bond; that is, a chemical compound with formula HO(O=)C–(CH
2)
k–CH=CH–(CH
2)
7-k–H, where k is between 0 and 7 inclusive.
EA-3990 is a deadly carbamate nerve agent. It is lethal because it inhibits acetylcholinesterase. Inhibition causes an overly high accumulation of acetylcholine between the nerve and muscle cells. This paralyzes the muscles by preventing their relaxation. The paralyzed muscles include the muscles used for breathing.
EA-4056 is a deadly carbamate nerve agent. It is lethal because it inhibits acetylcholinesterase. Inhibition causes an overly high accumulation of acetylcholine between the nerve and muscle cells. This paralyzes the muscles by preventing their relaxation. The paralyzed muscles includes the muscles used for breathing.
Methyl fluoroacetate (MFA) is an organic compound with the chemical formula FCH2CO2CH3. It is the extremely toxic methyl ester of fluoroacetic acid. It is a colorless, odorless liquid at room temperature. It is used as a laboratory chemical and as a rodenticide. Because of its extreme toxicity, MFA was studied for potential use as a chemical weapon.
Methyl isonicotinate is a toxic compound, which is used as a semiochemical. Other names for this compound are 4-pyridine carboxylic acid, and isonicotinic acid methyl ester. This compound is slightly toxic to the human body. It has an irritating effect on the eyes, skin, and respiratory tract. Moreover, the compound is used as the active ingredient in several sticky thrip traps to monitor and catch thrips in greenhouses.
1,4-Cyclohexanedimethanol diglycidyl ether is an organic chemical in the glycidyl ether family. Its formula is C14H24O4 and the IUPAC name is 2-[[4-(oxiran-2-ylmethoxymethyl)cyclohexyl]methoxymethyl]oxirane. It has the CAS number of 14228-73-0 and is REACH registered in Europe. An industrial chemical, a key use is in the reduction of the viscosity of epoxy resin systems functioning as a reactive diluent.