月: 2023年4月

What Is Menthone?

Menthone is a saturated cyclic terpene ketone, appearing as a clear, colorless liquid typically found in plant essential oils, notably peppermint oil and hackberry dehiscent oil. It mainly exists as l-menthone, known in IUPAC nomenclature as (2S,5R)-trans-2-isopropyl-5-methylcyclohexan-1-one, and is characterized by its peppermint-like aroma. L-menthone is extracted through fractional distillation of de-oiled peppermint oil.

Uses of Menthone

Menthone is used primarily as a synthetic fragrance material, commonly in mint scents. It’s also used in compounding agents for other fragrances like lavender, rose, and geranium, and in food flavorings and cosmetics. In the perfume industry, menthone contributes to the distinctive aroma of geranium oil, resembling that of rose oil. It’s also used in aromatherapy, often claimed to have blood pressure-lowering effects. Its pest-repelling effect makes it useful in pesticides and serves as a raw material in various organic syntheses.

Properties of Menthone

Menthone is slightly soluble in water but readily soluble in organic solvents like alcohol and benzene. It has a density of 0.893 g/cm3, a melting point of -6°C, and a boiling point of 207-210°C. Its molecular formula is C10H18O, and its molecular weight is 154.25. Menthone is a monoterpene with a carbonyl group, structurally similar to menthol but with a carbonyl group replacing the hydroxy group of menthol or added to p-menthane. There are four geometric and optical isomers of menthone due to the presence of two chiral carbons in the molecule.

Other Information on Menthone

1. Menthone Synthesis

Menthone can be synthesized through the oxidation of menthol using chromic acid. Like many secondary alcohols, menthol is susceptible to a variety of reactions.

2. Isomers of Menthone

L-menthone, also known as (-)-menthone, and its optical isomer d-menthone, or (+)-menthone, are two of the isomers of menthone. The geometric isomers, (-)-isomenthone (l-isomenthone) and (+)-isomenthone (d-isomenthone), are also derived from menthone.

3. Applications of Menthone

Menthone has been significant in the field of organic chemistry. Ernst Otto Beckmann demonstrated that dissolving menthone in concentrated sulfuric acid produced a ketone with a size similar to the raw material but with opposite optical rotation. He proposed a mechanism involving stereo inversion at the chiral carbon atom via an enol tautomer as an intermediate, providing an early example of theorizing the formation process of a product with nearly undetectable intermediates in the reaction mechanism.

What Is Anisol?

Anisol, with the chemical formula C₇H₈O, is also known as methyl phenyl ether or anisole. This organic compound is recognized for its role as an insect pheromone and is characterized by its sweet aniseed scent.

For safe storage, anisol should be kept tightly sealed in a cool, well-ventilated area, away from direct sunlight, high temperatures, sparks, flames, and static electricity. It is advisable to avoid mixing with strong oxidizing agents. Anisol is classified as a hazardous and flammable substance.

Uses of Anisol

Anisol serves multiple purposes, including as an organic solvent, synthetic intermediate, anthelmintic, soap, industrial fragrance, and raw material for economical fragrances. Its ortho- and para-directive reactivity with acetic anhydride to produce p-methoxyacetophenone, a compound used for its floral fragrance or flavor, is particularly notable.

Furthermore, anisol can react with disulfuric dirine pentasulfide to produce Lawson’s reagent, a sulfidizing agent capable of replacing oxygen atoms with sulfur atoms in organic compounds, with the chemical formula [(CH₃OC₆H₄)PS₂]₂.

Properties of Anisol

Anisol, a colorless liquid with a pleasant aroma, has a melting point of -37.5°C and boils at 155.5°C. It mixes well with ethanol and diethyl ether but is nearly insoluble in water. Its relatively low toxicity, with an LD50 in rats of 3,700 mg/kg, contrasts with its main hazard of flammability, highlighted by a low flash point of 52°C.

Due to the electron-donating methoxy group’s resonance effect, anisol exhibits a high electron density on the benzene ring, favoring ortho-para orientation in electrophilic reactions. The Hammett constants are -0.268 for the para effect and +0.115 for the meta effect.

Structure of Anisol

Anisol’s structure features a benzene ring with one hydrogen atom replaced by a methoxy group (–OCH₃), combining a methyl group (-CH₃) and a phenyl group (-C₆H₅) through an ether bond (-O-). Its molar mass is 108.14 g/mol, with a density of 0.995 g/mL.

Other Information on Anisol

1. Synthesis of Anisol

Anisol can be synthesized through the reaction of dimethyl sulfate with phenol in an alkaline solution, or via the Williamson synthesis involving sodium phenoxide and a methyl halide.

2. Reactions Involving Anisol

Besides forming p-methoxyacetophenone when reacted with acetic anhydride, anisol can engage in various chemical reactions, including the formation of π-complexes with metal carbonyls and the production of Lawson reagent through the reaction with diphosphorus pentasulfide (P₄S₁₀). The stability of anisol’s ether bond contrasts with the methyl group’s susceptibility to removal by hydroiodic acid, and its Birch reduction yields 1-methoxycyclohexa-1,4-dienes.

What Is Mequinol?

Mequinol is an organic compound formed when one hydrogen atom of phenol is replaced by a methoxy group. It is a type of phenol, also known as hydroxyanisole. There are three isomers: p-mequinol, o-mequinol, and m-mequinol, corresponding to the para-, ortho-, and meta-positions of the methoxy group on the phenol ring. Each isomer has a molecular formula of C7H8O2 and a molecular weight of 124.14.

Uses of Mequinol

1. P-Mequinol

P-Mequinol is used in organic synthesis, as an inhibitor of radical polymerization for monomers like acrylic acid esters and acrylonitrile, and as an antioxidant for fats, oils, fatty acids, and soaps. It is also utilized in fragrances and cosmetics for its antioxidative properties and pigmentation benefits.

2. O-Mequinol

O-Mequinol is used in the synthesis of organic compounds, as an antiseptic and disinfectant, and in the production of vanillin. It has applications as an antiseptic germicide, dental disinfectant, pain reliever, and intestinal fermentation inhibitor.

3. M-Mequinol

M-Mequinol is used as a catalyst and building block in organic compound synthesis, particularly as an antioxidant. It is also employed as a standard in gas chromatography analysis.

Properties of Mequinol

1. P-Mequinol

P-Mequinol is a white or light-yellow crystal, slightly soluble in water but soluble in ethanol and ether. It has a density of 1.55 g/cm3, a melting point of 126.5°F (52.5°C), and a boiling point of 469.4°F (243°C). P-Mequinol can be synthesized through the free radical reaction of methanol and 1,4-benzoquinone.

2. O-Mequinol

O-Mequinol is a slightly yellowish-white crystal with a characteristic odor. It is slightly soluble in water, but soluble in ethanol and acetone. O-Mequinol has a density of 1.112 g/cm3, a melting point of 82.4°F (28°C), and a boiling point of 399-403°F (204-206°C). It is produced through the thermal decomposition of lignin.

3. M-Mequinol

M-Mequinol is a clear, colorless to reddish-brown liquid, extremely soluble in ethanol and acetone but virtually insoluble in water. Its density is 1.143-1.148 g/cm3, with a melting point of 1.4°F (-17°C), and a boiling point of 471°F (244°C).

Structure of Mequinol

1. P-Mequinol

P-Mequinol, also known as 4-mequinol or 4-hydroxyanisole, contains a methoxy group at the 4-position of phenol.

2. O-Mequinol

O-Mequinol, also known as 2-mequinol or guaiacol, has a methoxy group at the 2-position of phenol.

3. M-Mequinol

M-Mequinol, also referred to as 3-mequinol or resorcinol monomethyl ether features a methoxy group in the 3-position of phenol.

What Is Methyl Mercaptan?

Methyl mercaptan (CH₃SH), known as mercaptomethane or methanethiol, is a thiol. This colorless gas, with its distinctive rotten cabbage smell, is a colorless gas at room temperature. It is flammable and releases toxic SOx gases upon decomposition.

It is recognized as a hazardous substance, requiring labeled notification, and risk assessment, and identified as a toxic substance. Additionally, it contributes to the odors of bad breath and flatulence.

Uses of Methyl Mercaptan

As a precursor to methionine, an essential amino acid, methyl mercaptan plays a vital role in the body’s synthesis of glutathione and taurine, substances linked to cholesterol decomposition and immunity enhancement.

Its applications extend to modifying catalytic activity in plastics, as an intermediate in organic synthesis, and in various industries including pharmaceuticals, pesticides, and jet fuel. It also serves as a detectable additive in odorless gases to facilitate leak identification.

Properties of Methyl Mercaptan

This organosulfur compound is soluble in polar solvents and exhibits reducing properties, reacting with oxygen and acids to form various compounds. Its potent odor, likened to mold, rotting food, and decaying proteins, is notable.

Its utility spans rubber and plastic sulfurization, synthetic chemistry intermediates, pharmaceutical synthesis, and gas leak detection additives due to these characteristics.

Structure of Methyl Mercaptan

Characterized by a tetrahedral structure, methyl mercaptan features a methane molecule with a substituted sulfur atom for a hydrogen atom. Its thiol group, more reactive than a hydroxyl group, imparts a strong odor, establishing it as a foundational organosulfur compound.

Other Information on Methyl Mercaptan

How Methyl Mercaptan Is Produced

Two prevalent production methods are:

1. Using Thioacetone as a Raw Material: This process involves reducing thioacetone with lithium aluminum hydride to produce methyl mercaptan.

2. Using Thiourea and Methyl Halides: A common laboratory and industrial method, this reaction replaces the halogen atom in methyl halides with a sulfur atom from thiourea, yielding methyl mercaptan.

This approach is favored due to the availability of raw materials and straightforward reaction conditions.

What Is Methyl Hesperidin?

Methyl hesperidin is a water-soluble form of hesperidin, a primary component of vitamin P, enhancing its application in various fields.

The IUPAC name is (2S)-2-(3,4-dimethoxyphenyl)-5-hydroxy-7- { [(2S,3R,4S,5S,6R)-3,4,5-trihydroxy-6- ( { [(2R,3R,4R,5R,6S)-3,4,5-trihydroxy-6-methyloxan-2-yl]oxy} [methyl) oxan-2-yl] oxy} -3,4-dihydro-2H-1-benzopyran-4-one (English: (2S) -2- (3,4-dimethoxyphenyl) -5-hydroxy-7- [ (2S,3R,4S,5S,6R) -3,4,5-trihydroxy-6- [ [ (2R ,3R,4R,5R,6S) -3,4,5-trihydroxy-6-methyloxan-2-yl] oxymethyl] oxy-2,3-dihydrochromen-4-one).

Uses of Methyl Hesperidin

As a flavonoid found in citrus fruits, hesperidin boasts physiological benefits, including supporting vitamin C effects, strengthening capillaries, and improving blood circulation. Its potential in antioxidant and antiallergic activities further underscores its versatility.

However, hesperidin’s water insolubility challenges its direct use, paving the way for methyl hesperidin’s development.

1. Cosmetic Additives

Methyl hesperidin, utilized in anti-aging cosmetics, targets melanin synthesis inhibition, glycation prevention, and blood flow enhancement. Its anti-glycation property is particularly noted for combating skin aging signs, thereby maintaining skin elasticity and transparency.

Furthermore, methyl hesperidin and vitamin C synergistically amplify each other’s effects, whether applied orally or transdermally.

2. Other Applications

Beyond cosmetics, methyl hesperidin is beneficial in nutritional foods and dietary supplements, attributed to its comprehensive health-promoting properties.

Properties of Methyl Hesperidin

With the chemical formula C₂₉H₃₆O₁₅ and a molecular weight of 624.59, methyl hesperidin’s solubility in water and dimethyl sulfoxide contrasts with its ethanol insolubility. Its CAS number is 11013-97-1.

This compound appears as a light yellow to brown crystalline solid, demonstrating its distinct physical characteristics.

Other Information on Methyl Hesperidin

1. Production Process

The production of methyl hesperidin involves methylation, desalting, and lyophilization, resulting in its crystalline form.

2. Precautions for Handling and Storage

Handling Precautions
To mitigate risks associated with its oxidizing nature, appropriate safety measures, including protective gear and handling practices, are recommended.

Utilize a draft chamber for safe use and ensure thorough post-use hygiene practices.

In Case of Fire
Address fire hazards with suitable extinguishers and firefighter equipment, mindful of potential toxic emissions.

Storage Recommendations
Emphasize secure, cool, and protected storage conditions to preserve methyl hesperidin’s integrity.

What Is Methyl Vinyl Ketone?

Methyl vinyl ketone (MVK) is a colorless to yellowish-brown liquid organic compound, known for its peculiar odor and tearing properties. It has a chemical structure consisting of a methyl group, a vinyl group, and a carbonyl group. The compound is highly reactive, soluble in water, and miscible in ethanol, diethyl ether, and acetone. MVK has a chemical formula of C4H6O, structural formula CH3COCH=CH2, molecular weight of 70.09, and CAS number 78-94-4. Its melting point is 19.4°F (-7°C), boiling point 178°F (81°C), and flash point 19.4°F (-7°C) in a closed system.

Uses of Methyl Vinyl Ketone

Methyl vinyl ketone is a versatile chemical intermediate used in the manufacture of resins, paints, and adhesives. It is also used as a starting material for synthesizing various organic compounds. It is particularly used in the production of acrylic and vinyl resins for paints and coatings, offering high adhesion, chemical resistance, and weather resistance. In the production of epoxy adhesives, MVK acts as a reactive diluent, enhancing flexibility and adhesive properties.

Properties of Methyl Vinyl Ketone

MVK is a colorless, flammable liquid with a strong pungent odor. Its molecular formula is CH3COCH=CH2 and it has a molecular weight of 70.09 g/mol. It is highly reactive, soluble in water, alcohols, ethers, and most organic solvents, and undergoes addition reactions with nucleophiles such as alcohols and amines. It can also polymerize with other monomers like styrene, acrylonitrile, and butadiene. MVK is toxic and irritating to the skin, eyes, and respiratory tract, and long-term exposure can cause liver and kidney damage.

Structure of Methyl Vinyl Ketone

The structure of MVK consists of a methyl group (-CH3), a vinyl group (-CH=CH2), and a carbonyl group (-C=O). The vinyl group’s double bond and the polar carbonyl group make the molecule highly reactive and soluble in polar solvents.

Other Information on Methyl Vinyl Ketone

Methyl Vinyl Ketone Production Process

MVK can be synthesized through various methods, including oxidation of isobutylene, dehydration of tertiary butyl alcohol, and dehydrogenation of 3-pentanone. The most common industrial method is the dehydrogenation of isopropyl alcohol using a copper or silver catalyst. This process occurs in the gas phase, where isopropyl alcohol is vaporized and fed into a reactor with a catalyst at 482-752°F (250-400°C). The resulting product is MVK, along with hydrogen gas as a byproduct. Post-reaction, MVK is separated from byproducts and unreacted isopropyl alcohol through distillation or other separation techniques.

What Is Glycidyl Methacrylate?

Glycidyl methacrylate (GMA), known scientifically as “2,3-epoxypropyl methacrylate,” is a versatile organic compound characterized by a clear colorless liquid form and a pungent odor. With properties including a melting point of -41.5°C and a boiling point of 189°C, GMA is recognized for its significant reactivity and utility in various industrial applications.

Uses of Glycidyl Methacrylate

Primarily utilized in the polymer industry, GMA is an effective monomer that copolymerizes with a wide range of other monomers, such as styrene, vinyl chloride, and acrylic acid, to create polymers with unique properties. These copolymers find applications in coating resins for acrylic powder paints, solvent-based paints, epoxy resin adhesives, vinyl chloride stabilizers, ion exchange resins, and printing inks. The presence of glycidyl (epoxy) groups allows for cross-linking reactions, enhancing the functionality of the resulting polymers.

Properties of Glycidyl Methacrylate

GMA exhibits dual functionality due to its polymerizable double bond and ring-opening glycidyl group. This unique structure enables it to be integrated into acrylic polymers, adding reactive capabilities for further chemical bonding, particularly with hydroxy groups (-OH) of other compounds, thus becoming a part of reactive acrylic polymers.

Structure of Glycidyl Methacrylate

The molecular structure of GMA combines the polymerizable double bond of methacrylic acid with the cyclic ether (3-membered ring) of glycidyl alcohol, making it capable of undergoing radical polymerization and ring-opening reactions. This dual functionality contributes to its wide range of applications in creating advanced polymer materials.

Other Information on Glycidyl Methacrylate

Glycidyl Groups of Glycidyl Methacrylate

The glycidyl group in GMA is akin to an epoxy group but contains an additional carbon atom. This structural distinction allows the glycidyl group to engage in ring-opening reactions, further broadening the scope of GMA’s applications in polymer chemistry.

What Is Metaldehyde?

Metaldehyde is an organic compound, specifically a tetramer of acetaldehyde. Its CAS registration number is 108-62-3, and it is commonly known as “metaacetaldehyde” or by its IUPAC name, “2,4,6,8-tetramethyl-1,3,5,7-tetraoxocane.” Classified under various regulations as both a poisonous and deleterious substance and as a designated combustible material, metaldehyde requires careful handling.

Uses of Metaldehyde

Metaldehyde’s primary application is as an insecticide, targeting slugs, snails, and certain other gastropods. It works by inducing paralysis and causing the pests to secrete mucus excessively, leading to dehydration and death. Metaldehyde is also used in camping and outdoor activities as a component of portable solid fuels.

Properties of Metaldehyde

With a molecular formula of C₈H₁₆O₄ and a molecular weight of 176.2, metaldehyde is a white solid with a distinctive menthol odor at room temperature. It has a melting point of 246.2°C, a sublimation point of 112°C, a density of 1.27 g/mL, and a flash point of 36°C. Although it is insoluble in water, it dissolves easily in organic solvents like toluene, methanol, benzene, and chloroform.

Types of Metaldehyde

Available primarily for research and development, metaldehyde is sold as a pure substance or polymer with the molecular formula (CH₃CHO)_n, and CAS registration number 9002-91-9. It is offered in various quantities suitable for laboratory use and may require specific storage conditions, such as refrigeration or room temperature.

Other Information on Metaldehyde

1. Synthesis of Metaldehyde

Metaldehyde can be synthesized through reactions involving acetaldehyde with calcium bromide and hydrogen bromide at 0°C or with calcium chloride and hydrochloric acid.

2. Chemical Reaction of Metaldehyde

As a colorless, needle-like crystal, metaldehyde can gradually convert to paraldehyde upon heating, decomposing to produce irritating smoke and gases starting at 80°C.

3. Basic Information on Metaldehyde With Degree of Polymerization N

As a polymer, metaldehyde is handled as a white crystalline powder with a melting point of 246.2°C and a flash point of 55°C. It is a flammable solid, soluble in hot chloroform, and mostly insoluble in water, ethanol, and acetone.

4. Toxicological Information on Metaldehyde

Metaldehyde poses risks of oral toxicity, eye irritation, and potential damage to the nervous system, liver, and testes upon long-term or repeated exposure. Ingestion can lead to a range of symptoms from mild to severe, including drooling, vomiting, diarrhea, high fever, and convulsions, necessitating cautious handling in compliance with safety regulations.