月: 2023年4月

What Is Chloroethane?

Chloroethane, also known as monochloroethane or ethyl chloride, is an alkyl halide with the chemical formula C2H5Cl. It is a type of organochlorine compound characterized by the replacement of one hydrogen atom in ethane with a chlorine atom.

Chloroethane is a colorless gas with an ethereal odor at room temperature and pressure. It has a melting point of -139°C, a boiling point of 12.3°C, and a density of 0.92 g/cm3. It is soluble in ethanol and acetone but insoluble in water.

Uses of Chloroethane

Historically, Chloroethane was primarily used as a raw material for tetraethyl lead, an anti-combustion agent in gasoline. Its use has declined due to environmental concerns. Other past uses included applications as a refrigerant, anesthetic, aerosol atomizer, and styrofoam blowing agent.

Currently, it is used industrially in the synthesis of ethylcellulose, a thickener, and binder in paints and cosmetics.

Properties of Chloroethane

Chloroethane is a white to pale yellow crystal or crystalline powder. It is flammable and classified as a metal corrosive, skin corrosive/irritant, and eye irritant under the GHS classification.

Structure of Chloroethane

The differential formula of Chloroethane is CH3CH2Cl, with a molar mass of 64.51 g/mol.

Other Information on Chloroethane

1. Synthesis of Chloroethane

Chloroethane was first synthesized by reacting ethanol with hydrochloric acid or zinc chloride. It can also be produced by adding hydrogen chloride to ethylene, using an aluminum chloride catalyst at high temperature and pressure. Additionally, Chloroethane is a byproduct in the manufacture of polyvinyl chloride.

2. Reaction of Chloroethane

Chloroethane can react with a lead-sodium alloy to synthesize tetraethyllead, an anti-knock agent in engines. Tetraethyllead is a colorless, volatile liquid with a peculiar odor, flammable, and highly neurotoxic.

3. Hazards of Chloroethane

While Chloroethane is the least toxic of the chloroethanes, it can still depress the central nervous system. Inhalation of high concentrations can cause symptoms similar to alcohol intoxication, and prolonged exposure can be fatal. It is recommended to remove victims from exposure areas to regain consciousness, and prolonged exposure may require hydration and nutritional support for recovery.

What Is a Chlorophenol?

Figure 1. Structure of Monochlorophenol

Chlorophenol is an aromatic compound consisting of phenol bonded with chlorine.

It is classified into monochlorophenol, dichlorophenol, trichlorophenol, tetrachlorophenol, and pentachlorophenol according to the number of chlorine atoms. Monochlorophenol has three isomers: o-chlorophenol, m-chlorophenol, and p-chlorophenol. Taking into account positional isomers, there are a total of 19 chlorophenols.

Most chlorophenols are solid at room temperature and have a strong medicinal taste and aroma. They are generally available as herbicides, insecticides, and disinfectants. Chlorophenol is an endocrine disruptor and is regulated by law because it affects the thyroid gland and other organs.

Uses of Chlorophenols

Chlorophenol is mainly used as an intermediate in agrochemicals, pharmaceuticals, and dyes.

• o-chlorophenol is used as an intermediate in dyes and as a raw material for agricultural chemicals.
• m-chlorophenol is available as an intermediate in pharmaceuticals and agrochemicals, for dyeing nitrogen-containing fibers, and as a raw material for adhesives and heat-resistant resins.
• p-chlorophenol is used as an intermediate in dyes, as a disinfectant, and as a preservative in cosmetics. It was previously used as a preservative in textile and leather goods.

Properties of Chlorophenols

O-chlorophenol, also called 2-chlorophenol or 2-chloro-1-hydroxybenzene, is a colorless to light red liquid. It is insoluble in water and very soluble in ethanol and acetone.

m-chlorophenol, also called 3-chlorophenol or 3-chloro-1-hydroxybenzene, is a colorless to yellowish-brown liquid. It is almost insoluble in water, but soluble in ethanol and acetone.

p-chlorophenol, also called 4-chlorophenol or 4-chloro-1-hydroxybenzene, is a white to light brown mass or liquid. It has a characteristic odor and is insoluble in water, but soluble in ethanol.

Structure of Chlorophenols

Chlorophenol is an organic chloride of phenol containing one or more covalently bonded chlorine atoms. Chlorophenol is formed by electrophilic halogenation of phenol with chlorine.

Except for the carbon atom to which the hydroxy group is attached, chlorine atoms are attached to five carbon atoms of the benzene ring of the phenol molecule, making a total of 19 types of chlorophenol.

There are three types of monochlorophenol, in which one hydrogen atom of phenol is replaced by a chlorine atom.

Other Information on Chlorophenol

1. Structure of Dichlorophenol

Figure 2. Structure of Dichlorophenol

Dichlorophenol is a compound in which two hydrogen atoms of phenol are replaced by chlorine atoms. There are six isomers of dichlorophenol: 2,3-dichlorophenol, 2,4-dichlorophenol, 2,5-dichlorophenol, 2,6-dichlorophenol, 3,4-dichlorophenol and 3,5-dichlorophenol.

2. Other Isomers of Chlorophenol

Figure 3. Structure of Chlorophenol

Trichlorophenol is a compound in which three hydrogen atoms of phenol are replaced by chlorine atoms. 6 isomers exist: 2,3,4-trichlorophenol, 2,3,5-trichlorophenol, 2,3,6-trichlorophenol, 2,4,5-trichlorophenol, 2,4,6 -trichlorophenol, and 3,4,5-trichlorophenol.

Tetrachlorophenol is a compound in which the four hydrogen atoms of phenol are replaced by chlorine atoms. 3 isomers exist: 2,3,4,5-tetrachlorophenol, 2,3,4,6-tetrachlorophenol and 2,3,5,6-tetrachlorophenol.

Pentachlorophenol is a compound in which the five hydrogen atoms of phenol are replaced by chlorine atoms. Because all five hydrogen atoms of phenol have been replaced by chlorine atoms, there is only one structure of pentachlorophenol.

What Is Chlorocyclohexane?

Chlorocyclohexane is an organochlorine compound in which one hydrogen atom of cyclohexane is replaced by chlorine. Its chemical formula is C6H11Cl.

It is also called cyclohexyl chloride and exists as a liquid state with a pungent odor at room temperature.

Uses of Chlorocyclohexane

Chlorocyclohexane has various uses as an intermediate compound for agrochemical raw materials, rubber raw materials, and pharmaceuticals. The following is an example of one of these uses as a synthetic material for rubber raw materials.

Chlorocyclohexane is used to produce a substance called N-cyclohexylthiophthalimide. The phenomenon in which rubber hardens during storage or molding and becomes difficult to process is called the scorch phenomenon. N-Cyclohexylthiofthalimide acts as a scorch inhibitor in rubber processing.

Properties of Chlorocyclohexane

1. Flammability

Chlorocyclohexane is extremely flammable and is easily ignited by flame, heat or sparks. Because chlorocyclohexane contains chlorine in its composition, it can produce an irritating odor and toxic chlorine-containing gases when it burns.

Cyclocyclohexane is also highly flammable, and chlorocyclohexane, which is similar in structure to cyclohexane, is also highly flammable.

Chlorocyclohexane is less flammable than cyclohexane because of the chlorine bond. In fact, lindane, in which six of cyclohexane’s hydrogens are replaced by chlorine, is nonflammable.

2. Solubility

Chlorocyclohexane is virtually insoluble in water. Quantitative solubility is 500ml per liter of water. It is very soluble in ethanol and acetone.

3. Toxicity

Chlorocyclohexane is toxic to animals and plants, including humans. This property is used as a raw material for pesticides and insecticides.

Chlorocyclohexane is a type of organochlorine compound. Organochlorine compounds are a general term for organic compounds that contain chlorine in their molecules. Most organochlorine compounds are artificially synthesized and rarely found in nature.

Most organochlorine compounds are highly toxic, and it is said that there is no organochlorine compound that is not toxic.

The use and emission of chlorofluorocarbons (CFCs), which destroy the ozone layer, and dioxin and trihalomethane, which have attracted attention for their environmental problems, are regulated by law.

Structure of Chlorocyclohexane

1. Stereo Conformation of Chlorocyclohexane

The cyclohexane ring has a strain-free three-dimensional structure called a chair conformation. It is called chair conformation because it is shaped like a lounge chair with a backrest, a seat, and a footrest. The chair-shaped cyclohexane ring has all C-C-C bond angles of 111.5°, close to the most stable tetrahedral angle of 109.5°.

In addition to the chair configuration, the cyclohexane ring has another stereo configuration called the ship-shaped configuration. This boat-shaped configuration has no angular strain, but it does have torsional strain due to the overlapping electron orbitals of the C-H bonds between adjacent carbon atoms. Therefore, it is more unstable than the chair-shaped configuration.

2. Axial and Equatorial Bonds in Chlorocyclohexane

Chlorine attached to the cyclohexane ring can take two different positions: axial and equatorial.

The axial position is parallel to the ring axis, i.e., perpendicular to the ring, while the equatorial position is around the equator of the ring, approximately in the same plane as the ring.

The equatorial position is more stable because the chlorine at the axial position is torsionally distorted due to interference with the hydrogen at the axial position.

Other Information on Chlorocyclohexane

1. Production of Chlorocyclohexane

Chlorocyclohexane is produced by chlorination of cyclohexane or by heating cyclohexanol with hydrochloric acid.

What Is a Chloride?

Chloride refers to chloride, a generic term for compounds in which chlorine forms with a more positive atom or group of atoms.

In nomenclature, compounds with chlorine atoms are denoted either by prefixing “chloride” or “chloro” or by suffixing “chloride. Chlorine Cl₂ can react with almost any element except Group 18 elements to form chlorides, and if the chlorine bond is ionic, it readily liberates the chloride ion Cl⁻.

Inorganic chlorides containing chlorine atoms are in most cases ionically bonded. In water, they ionize into chloride ions and inorganic cations and readily dissolve in water.

Uses of Chlorides

Chlorides (chlorides), which are compounds of chlorine, are used throughout our daily lives.

1. Hydrogen Chloride

Hydrogen chloride is a substance with the molecular formula HCl. It is a gas at room temperature, soluble in water, and its aqueous solution is highly acidic. Taking advantage of this feature, hydrochloric acid is used not only as a catalyst and neutralizer in many chemical reactions, but also in acid catalytic reactions, neutralization of alkaline substances, and in the formation process of sodium hydroxide (caustic soda). In addition, it is sometimes used industrially to clean and remove corrosion from metal surfaces.

2. Oxoacid

Oxoacids are acids that contain oxygen atoms in their molecules. There are four types: hypochlorous acid HClO, chlorous acid HClO₂, chloric acid HClO₃, and perchloric acid HClO₄. Aqueous solutions of HClO hypochlorite have bleaching and disinfecting properties and are used to bleach clothes and disinfect tap water. Of these salts, potassium chlorate KClO₃ has strong oxidizing properties. It is therefore used as an oxidizing agent in matches and gunpowder.

3. Halogen Salts

Halogen salts are salts in which halogens are compounded with metallic elements such as sodium and potassium. Most of them are easily soluble in water, but silver halide and lead(II) halide, other than fluorine, are insoluble in water.

Silver halide is photosensitive to light, absorbing light energy when exposed to light and changing into silver ions and halide ions. This is the mechanism by which dark and light areas are formed on photographic film and photosensitive paper.

4. Organic Chlorides

Organic chlorides containing chlorine atoms are stable covalent compounds in which the chlorine atom is bonded to the sp3 carbon. chloro groups substituted on the sp3 and sp2 carbons are easily desorbed, and such organic chlorides are used as substrates for desorption reactions. In nucleophilic substitution reactions such as Williamson synthesis, the chloro group on the sp3 carbon is also used as a leaving group.

For example, benzyl chloride (benzyl chloride) is used in organic synthesis to replace the hydrogen of the OH group of alcohols, carboxylic acids, and phenols with a benzyl group. This is one method of protecting the OH group with a benzyl group (benzyl protection).

Properties of Chlorides

Chlorides are based on the properties of chlorine alone and its compound, Chloride.

1. Properties of Chlorine

Chlorine, also called halogen, is a group of 17 elements on the periodic table. The word halogen comes from the Greek words halos (salt) and Gennaro (to make).

It has a valence electron number of 7 and a high electron affinity, making it easy to form a monovalent anion. In nature, it does not exist by itself but exists as a compound.

Molecular Formula	Cl2
Stand-alone state (At Room Temperature and Pressure)	Yellow-green gas
Molecular Weight	71
Boiling Point (°C)	−101
Oxidizing Power	Strong

 

Chlorine is highly oxidizing, so when dissolved in water, some of it reacts to form hydrogen chloride HCl and hypochlorous acid HClO. These substances are typical Chlorides.

2. Properties of Chlorides

Chlorides are compounds with a single chlorine atom as the anion. The chloride ion is a monovalent anion without charge. They generally combine with metals to form ionic crystals, but some compounds contain carbon and hydrogen, such as organic chlorides.

Chlorides occur in many forms in nature and are well known to be a major component of salt in seawater. Sodium chloride (salt) is another example of chloride. Chlorides play an important role in many chemical reactions and industrial processes.

For example, hydrogen chloride (hydrochloric acid) is widely used as a strong acid, and alkyl chloride is used in organic synthesis. In addition, iron chloride is useful as a rust inhibitor and pigment.

Other Information on Chlorides

Utilization of Chlorides

Some chlorides are used as ingredients in shampoo and treatment products. Ingredients in shampoo formulations include detergents, surfactants, water, and fragrance. Some chlorides are included as surfactants.

Because our hair is negatively charged, chlorides used as surfactants are strongly adsorbed and highly persistent. Some of the most commonly used are behentrimonium chloride, steartrimonium chloride, and distearyldimonium chloride.

Recent studies have shown that these substances have a negative effect on hair quality because they have a strong protein denaturing effect and are difficult to wash out.

What Is a Creatine?

Creatine is an odorless, white, crystalline powder.

Its chemical formula is C₄H₉N₃O₂, molecular weight is 131.13, and its CAS number is 57-00-1, it is also called 2-(1-Methylguanidino)acetic Acid. Creatine occurs naturally in the human body, with more than 90% found in muscle and some in the brain.

The body’s total creatine stores are estimated to be about 120 g for an adult weighing 70 kg. Creatine is synthesized in the body from three amino acids (arginine, glycine, and methionine), mainly in the liver and kidneys.

The body synthesizes only about half of the daily requirement of creatine, and any deficiency must be obtained from food or supplements. Creatine is abundant in raw meat and fish, but its content is reduced by cooking.

Uses of Creatines

Creatine is used to resynthesize ATP (a substance found in cells that is necessary to store and use energy used in vital activities), which is the energy used by muscles to contract and is present in muscles as creatine phosphate.

During exercise, the energy generated when ATP is broken down is used, but because there is a limit to the amount of ATP, the resynthesis of ATP by creatine phosphate is necessary for continued exercise. Creatine has the effect of increasing endurance and muscle strength during exercise and other physical activities, so creatine’s ability to increase athletic performance is useful mainly during repetitive, short, intense exercise.

In addition to athletes, the effects of creatine on the athletic performance of the elderly are also being studied, and the use of creatine to maintain muscle strength and rehabilitation of the elderly is being investigated.

Properties of Creatines

Creatine has a melting point (decomposition temperature) of 303°C and is slightly soluble in water, but not in ether. Creatine is found in vertebrates and facilitates the recycling of adenosine triphosphate (ATP), primarily in muscle and brain tissue.

Recycling is accomplished by converting adenosine diphosphate (ADP) back to ATP through the donation of phosphate groups. Creatine also acts as a buffer.

Other Information About Creatines

1. Biosynthesis of Creatines

Creatine is an amino acid derivative that is naturally produced in the human body from the amino acids glycine and arginine. In the first step of biosynthesis, the enzyme arginine (glycine amidinotransferase, AGAT) mediates the reaction of glycine and arginine to form guanidinoacetic acid.

This product is then methylated by guanidinoacetic acid N-methyltransferase (GAMT) using S-adenosylmethionine as the methyl donor. Creatine is phosphorylated by creatine kinase to form creatine phosphate, which is used as an energy buffer for skeletal muscle and the brain. A cyclic form of creatine called creatinine exists in equilibrium with its tautomer and creatine.

2. Handling and Storage Precautions

Precautions for handling and storage are as follows

• Keep the container tightly closed and store it in a dry, cool, dark place.
• Use only outdoors or in well-ventilated areas.
• Store away from oxidizing agents and other incompatible materials.
• Be aware that decomposition produces carbon monoxide, carbon dioxide, nitrogen oxides, and other gases.
• Wear protective gloves, eye protection, protective clothing, and protective masks when using.
• Take care not to inhale dust or aerosol.
• Wash hands thoroughly after handling.
• In case of skin contact, flush immediately with water.
• In case of eye contact, rinse cautiously with water for several minutes.

What Is Coumaric Acid?

Figure 1. Basic Information on p-Coumaric Acid

Coumaric acid is a hydroxy derivative of cinnamic acid, not silicylic acid as previously mentioned. It includes three isomers: p-coumaric acid, m-coumaric acid, and o-coumaric acid, depending on the hydroxy group’s position on the phenyl group. p-Coumaric acid, the most abundant naturally occurring form among these, is found in various edible plants such as tomatoes, peanuts, garlic, and carrots. It is also referred to as 4-hydroxycinnamic acid or β-(4-hydroxyphenyl)acrylic acid.

Uses of Coumaric Acid

Coumaric acid is primarily used as a reagent in chemical research. It serves as a component in chemiluminescent substrates for protein detection in western blotting. Additionally, coumaric acid inhibits the formation of nitrosamines, carcinogens formed by the reaction of amines with nitrites in food additives. This inhibition is particularly relevant to reducing the risk of stomach cancer, making p-coumaric acid a subject of ongoing research.

Properties of Coumaric Acid

p-Coumaric acid is a crystalline solid with a melting point of 410-415.4°F (210-213°C) and a boiling point of 449°F (231.61°C). It is insoluble in water but dissolves well in diethyl ether and ethanol.

Structure of Coumaric Acid

Figure 2. Structure of Coumaric Acid

The molar mass of coumaric acid is 164.16 g/mol, with a chemical formula of C₉H₈O₃. It features a structure of a hydroxy group bonded to a phenyl group. Among its forms, trans-p-coumaric acid is a major component of lignin. p-Coumaric acid derivatives, such as p-coumaric acid glucoside, are found in various natural products, including bread containing ama seeds and carnauba wax.

Other Information on Coumaric Acid

1. Synthesis of p-Coumaric Acid

Figure 3. p-Coumaric Acid Synthesis

p-Coumaric acid is produced by the cytochrome P450-dependent enzyme trans-cinnamic acid-4-monooxygenase from cinnamic acid and from L-tyrosine by tyrosine ammonia lyase.

2. p-Coumaric Acid Reaction

p-Coumaric acid is a precursor to 4-ethylphenol in wine, produced by Brettanomyces yeast. It is converted from coumaric acid to 4-vinylphenol by 4-hydroxycinnamic acid decarboxylase and then reduced to 4-ethylphenol by vinylphenol reductase. Additionally, cis-p-coumaric acid glucosyltransferase synthesizes p-coumaric acid glucoside from cis-p-coumaric acid and UDP-glucose.

3. Characteristics of m-Coumaric Acid and o-Coumaric Acid

m-Coumaric acid and o-coumaric acid, found in vinegar, are produced through various metabolic pathways involving enzymes like 2-coumaric reductase, which is involved in phenylalanine metabolism.

What Is Quinoxaline?

Figure 1. Quinoxaline and Its Isomers

Quinoxaline is a heterocyclic compound with the chemical formula C₈H₆N₂, consisting of a benzene ring fused to a pyrazine ring. It is also known as benzopyrazine, and its CAS registration number is 91-19-0. Quinoxaline differs from its isomers — quinazoline, cynnoline, and phthalazine — and does not fall under any specific GHS classification.

It is not subject to regulation under the Industrial Safety and Health Law, the Labor Standards Law, the PRTR Law, or the Poisonous and Deleterious Substances Control Law.

Uses of Quinoxaline

Quinoxaline is widely used as a dye, but also as a functional material in applications such as photoreceptors for electrophotography. Additionally, it serves as an intermediate and starting material in the pharmaceutical and agrochemical industries. Compounds featuring the quinoxaline structure can inhibit enzyme activity by capturing metal ions involved in metabolic processes, leading to its use in fungicides, acaricides, and antibiotics such as ethinomycin, levomycin, and actinoleutin.

Properties of Quinoxaline

Figure 2. Basic Information on Quinoxaline

Quinoxaline has a molecular weight of 130.15, a melting point of 84-90 °F (29-32 °C), a boiling point of 428-433 °F (220-223 °C), and takes the form of a white or yellow crystal or mass at room temperature. It has a density of 1.124 g/mL and a flash point of 208 °F (98 °C). Quinoxaline is soluble in water and ethanol.

Types of Quinoxaline

Quinoxaline, primarily sold as a reagent for research and development, is available in quantities suited for laboratory use, such as 25g. Due to its low melting point, it is often stored at refrigerated temperatures of 32-50 °F (0-10 °C).

Other Information on Quinoxaline

1. Synthesis of Quinoxaline

Figure 3. Example of Synthesis of Quinoxaline

Quinoxaline synthesis typically involves reacting o-diamines with diketones. Unsubstituted quinoxaline can be produced by reacting o-phenylenediamine with glyoxal. Other methods include the synthesis of quinoxaline derivatives from o-phenylenediamine and benzyl, using 2-iodoxybenzoic acid (IBX) as a catalyst. Various functional groups can be introduced into the quinoxaline structure using substituents such as α-keto acids, α-chloroketones, α-aldehyde alcohols, and α-ketone alcohols as diketones.

2. Reactivity of Quinoxaline

Quinoxaline is stable under normal storage conditions but is considered a flammable organic substance. If finely dispersed, a dust explosion may occur, although no hazardous interactions have been specifically identified.

3. Derivatives of Quinoxaline

Available derivatives of quinoxaline include quinoxaline-2,3-dithiol, quinoxaline-2,3-diol, quinoxaline-2-carboxyaldehyde, quinoxaline-5-ol, quinoxaline-6-methyl carboxylate, and carboxylic acid-6-amine, all sold for research and development purposes.

4. Precautions for Handling Quinoxaline

Although not classified under the GHS, quinoxaline should be handled with care due to potential skin and eye irritation risks. Personal protective equipment such as gloves, eye protection, and face protection is recommended. In case of skin or eye contact, rinse thoroughly with water. If wearing contact lenses, remove them if possible, and continue rinsing.

What Is Quinuclidine?

Quinuclidine is a heterocyclic amine with the chemical formula C₇H₁₃N. It is also known as 1,4-ethanopiperidine. Its molecular weight is 111.18, CAS number is 100-76-5, density is 1.025 g/cm³, and melting point is 158°C (316°F).

Its IUPAC name is 1-azabicyclo[2.2.2]octane. It is a sublimable, colorless to milky solid. As a natural product, quinuclidine is categorized as an alkaloid, prominently featured in the molecular structure of quinine, a well-known anti-malarial alkaloid.

Uses of Quinuclidines

1. Starting Material

Quinuclidine serves as a foundational material for pharmaceuticals and functional materials, embodying many natural products that incorporate the quinuclidine structure. A prime example is quinine, celebrated for its anti-malarial properties.

Quinine, commonly administered as quinine hydrochloride or quinine sulfate to enhance solubility in water, exhibits specific toxicity towards Plasmodium falciparum. This parasite metabolizes hemoglobin in erythrocytes for nutrition. However, the resultant heme is toxic to the parasite, which it counteracts by polymerizing heme into a nontoxic form using heme polymerase. Quinine’s anti-malarial action is theorized to stem from its inhibition of heme polymerase.

Beyond quinine, numerous natural products featuring the quinuclidine structure exhibit diverse bioactivities. Recent years have seen significant interest in their asymmetric synthesis, with quinuclidine utilized as a key starting material.

2. Catalyst

Quinuclidine’s strong nucleophilic properties make it a valuable catalyst in chemical reactions, such as the addition of alkenes to aldehydes in the Morita-Baylis-Hillman reaction. The potential for functionalization to introduce a chiral point into compounds underscores its significance in the development of asymmetric synthetic catalysts.

Properties of Quinuclidines

1. Physical Properties

The [2.2.2]bicyclooctane ring endows quinuclidine with distinctive physical properties, enhancing its solubility compared to conventional amine compounds due to its unique structure.

2. Chemical Properties

Quinuclidine exhibits unique chemical behaviors not common to typical amides, including increased reactivity due to its steric structure. This structure limits electron pair conjugation with the pi orbitals of carbonyl carbon and oxygen, rendering the carbonyl carbon more susceptible to nucleophilic attack. Its pronounced nucleophilicity can be attributed to the fixed position of the non-covalent electron pair by the ring structure and the minimal steric hindrance around the nitrogen atom.

Other Information on Quinuclidines

Hazards of Quinuclidines

Despite its acute toxicity and potential to cause skin and eye irritation, quinuclidine is not subject to regulation under major safety and health legislations. Its handling requires careful consideration of its hazardous properties.

What Is Quinazoline?

Quinazoline is an organic compound with the molecular formula C8H6N2, known for its role in organic synthesis and pharmaceutical applications. It is a colorless to pale yellow crystalline powder with a characteristic odor, soluble in ethanol and acetone but insoluble in water.

The CAS number of quinazoline is 253-82-7. It has a molecular weight of 130.15, a melting point of 120-122°F (49-50°C), a boiling point of 469.4°F (243°C), and a density of 1.351 g/cm3. Its flash point is 222.8°F (106°C), and it has an acid dissociation constant (pKa) of 3.51.

Uses of Quinazoline

Quinazoline and its derivatives are primarily used in organic synthesis. In medicine, these compounds serve as anti-malarial agents, and treatments for brain tumors, and other cancers. Quinazoline rings are also integral to antihypertensive drugs like doxazosin. Additionally, quinazoline compounds find applications in electronics, particularly in organic light-emitting diode (OLED) materials for displays.

Properties of Quinazoline

Quinazoline is prone to various addition reactions, particularly at the N3 position, and undergoes hydrolysis in acidic or alkaline solutions. The decomposition products include 2-aminobenzaldehyde, formic acid, and ammonia. Its benzene ring is more reactive to electrophilic substitution reactions compared to the pyrimidine ring.

Types of Quinazoline

Available mainly for research and development purposes, quinazoline is sold in small quantities like 1 g or 5 g, and is considered a relatively expensive reagent. It is commonly handled at room temperature. Derivatives of quinazoline available commercially include 4-chloroquinazoline and quinazoline-2-carboxylic acid hydrochloride, among others.

Other Information on Quinazoline

1. Synthesis of Quinazoline

Quinazoline can be synthesized through various methods, including the Niementowski quinazoline synthesis, which involves the reaction of anthranilic acid with amino acids. Another efficient method includes the introduction and removal of a tosylhydrazide group to 4-chloroquinazoline.

2. Derivatives of Quinazolines

Derivatives of quinazoline, such as tyrosine kinase inhibitors, are used in molecular targeted therapies. Examples include gefitinib, erlotinib, afatinib, and lapatinib, which are used for treating various cancers.

What Is Camphor?

Camphor is an organic compound with the chemical formula C₁₀H₁₆O. It is a bicyclic monoterpene that belongs to the norbornane family, characterized by three added methyl groups. This substance forms colorless hexagonal platelet crystals and is known for its fragrant, penetrating odor. Camphor is sublimable, meaning it can transition directly from a solid to a gas under certain conditions.

While not typically handled as a standalone product, camphor is often sold as camphor acid chloride for use as a reagent. Under the Globally Harmonized System (GHS) of Classification and Labelling of Chemicals, camphor is classified as a substance that is corrosive to metals and an irritant to the skin and eyes.

Uses of Camphor

Camphor, as a well-known bicyclic monoterpene skeleton, is the basis for many naturally occurring compounds. Its various physiological effects, such as enhancing blood circulation, providing analgesia, and reducing inflammation, are noteworthy. These properties are attributed to the bicyclic monoterpene compounds derived from the camphor skeleton.

Although the direct use of camphor in its pure form is quite limited, significant research has been conducted on its derivatives, including norbornene and norbornane compounds, and other monoterpene compounds. These studies focus on exploring their diverse bioactivities and potential applications.