月: 2023年4月

What Is Aldol?

Aldol generally refers to compounds containing both an aldehyde and a hydroxy group. Aldol compounds are typically formed through the aldol reaction, which involves the combination of two aldehyde molecules.

3-Hydroxybutanal, an example of such a compound with both an aldehyde and a hydroxy group, is often referred to as aldol. This organic compound is typically a colorless liquid under standard room temperature and pressure conditions.

In a broader sense, aldol refers to compounds like 3-Hydroxybutanal, which are produced by the aldol reaction of simpler aldehydes such as acetaldehyde.

Uses of Aldol

3-Hydroxybutanal was once used as a sleeping pill but is now no longer used.

Aldol, in the broad sense, is a product of the aldol reaction, known as the main reaction that connects two carbon atoms.

The aldol reaction involves synthesizing a hydroxycarbonyl compound from an enolate ion and a ketone, both derived from carbonyl compounds. If the two reactants are both aldehydes, the synthesized compound will have both an aldehyde group and a hydroxy group. In other words, the aldol reaction between aldehydes produces aldol. This property is the origin of the name “aldol reaction.”

What Is Allylamine?

Allylamine is an organic compound with the chemical formula C3H7N and the specific formula CH2=CHCH2NH2.

Its IUPAC nomenclature names are prop-2-ene-1-amine and 3-amino-1-propene; other names include 3-aminopropene, 3-aminopropylene, monoallylamine, 2-propenamine, 2-propen-1-amine, etc. Its CAS registration number is 107-11-9.

It has a molecular weight of 57.09, a melting point of -126.4°F (-88°C), and a boiling point of 131°F (55°C). It is a clear colorless to pale yellow liquid at room temperature. It has a density of 0.76 g/mL and a strong, pungent odor. It is extremely soluble in water, ethanol, and acetone.

It has an extremely low flash point of -18.4°F (-28°C). It is also a highly flammable liquid or vapor.

Uses of Allylamine

Allylamine is used as a raw material for agricultural chemicals, a modifier of polymer compounds, and a pharmaceutical intermediate. Some of its derivatives are also used as allylamine antifungal agents.

For example, terbinafine (trade name Lamisil) is an antifungal agent indicated for the treatment of dermatophytes and dermatomycoses caused by Candida, Sporothrix, and other fungi. One of its derivatives, diallylamine, is used as an important intermediate in industrial synthesis.

Properties of Allylamine

The 2-propenyl group (-CH2CH=CH2) in allylamine is called the allyl group, and the carbon position adjacent to the double bond is called the allyl position. The allyl group is distinct from the aryl group, which denotes an aromatic group, having a different structure.

The allyl group is used as a protecting group for alcohols and amines and is deprotected by palladium catalysts. In allylamine, the allyl group can also be removed by using palladium.

Carbocation, carbo-anion, and radical at the allyl position are stabilized by resonance. Therefore, allylamine tends to polymerize, forming homopolymers (polyallylamine) or copolymers. These polymers are used in reverse osmosis membranes.

Types of Allylamine

Allylamines sold as products are mainly reagent products for research and development and industrial chemicals. Reagent products are available in capacities of 25 ml, 50 ml, 500 ml, 5 g, 25 g, etc. These reagent products can be handled at room temperature.

Related compounds, such as allylamine hydrochloride and poly(allylamine) solution, are also available as reagent products. Various derivatives such as diallylamine and N-allylmethylamine are also sold as reagent products for organic synthesis in many compounds.

Other Information on Allylamine

1. Synthesis of Allylamine

Mixtures of allylamine (monoallylamine), diallylamine, and triallylamine are obtained by treating allyl chloride with aqueous ammonia or hexamine. Pure allylamine can also be synthesized by hydrolysis of allyl isothiocyanate.

2. Chemical Reaction of Allylamine

Allylamine reacts with nitrous acid to give allyl alcohol. It can also be methylated with methyl iodide to form N-allylmethylamine. Reaction with bromine in an acidic solution leads to an addition reaction to alkenes, yielding 2,3-dibromopropylamine.

3. Regulatory Information on Allylamine

Allylamine is designated as a toxic substance. Handling in compliance with laws and regulations is required.

What Is an Allyl Radical?

An allyl radical is an organic compound with the chemical formula C3H5 and is known for its high stability due to the delocalization of radicals to the three carbons in the compound by resonance. Although the name originally refers to a single compound, it is generally used as a generic term for compounds with radicals on the allylic carbon, rather than the compound itself.

Although more stable than ordinary radicals, they are not isolated and exist only as reaction intermediates. Therefore, there is no GHS classification or legal requirement for allyl radicals themselves. Therefore, it is necessary to check the starting material, the allyl compound, and its reaction products.

Uses of Allyl Radical

Allyl radicals are used in various ways, including as stable reaction intermediates. Compounds with radicals on carbon atoms exist as intermediates in various reactions. Allyl radicals, like benzyl radicals, are stable intermediates that facilitate the progress of reactions.

Specifically, it is present as an intermediate in the well-known Wall-Ziegler reaction, a bromine addition reaction to a double bond, and is known to affect the regioselectivity of the bromine addition.

What Is an Allyl Cation?

An allyl cation is an organic compound with the chemical formula C3H5, and is known for its high stability due to the delocalization of positive charges to the three carbons in the compound by resonance. Although the name originally refers to a single compound, it is sometimes used as a generic term for carbocations with a positive charge on the allylic carbon, rather than the compound itself.

In either case, allyl cation is more stabilized than other carbocations. However, they are usually not isolated and exist as reaction intermediates. Therefore, there is no GHS classification or regulatory requirement for allyl cations themselves. As a result, it is necessary to check the starting material, the allyl compound, and its reaction products.

Uses of Allyl Cation

Allyl cations are used in various ways, including as stable reaction intermediates. Carbocations with a positive charge on a carbon atom exist as intermediates in various reactions, among which allyl cations are stable intermediates that facilitate the progress of reactions. Specifically, they are present as intermediates in the addition reaction of hydrogen halides to allyl compounds and are known to affect the regioselectivity of the addition.

Since allyl cations are polymerizable, the development of allyl cationic polymers using allyl cations themselves as monomers is underway, and these are also uses of the stability of allyl cations themselves.

What Is Aminosilane?

Aminosilane is a general term referring to silicon compounds with amino groups.

An amino group is a functional group represented by the general formula -NH₂, -NHR, -NRR’. In many cases, it is used as a generic term for silane coupling agents with an amino group as a functional group (amino silane coupling agents).

Uses of Aminosilane

Aminosilane compounds are mainly used in semiconductor manufacturing and as silane coupling agents.

1. Semiconductor Manufacturing

Aminosilanes are used in semiconductor manufacturing for the deposition of silicon oxide films using chemical vapor deposition (CVD). Examples of such substances include tris-dimethylaminosilane (3DMAS), diisopropylaminosilane, and bis(tert -butylamino)silane (BTBAS).

2. Amino Silane Coupling Agent

The main applications of amino silane coupling agents are surface treatment agents for glass fibers, resin modifiers, and adhesion aids. In particular, in the surface treatment of glass fibers, there is hardening that improves mechanical strength, heat resistance, water resistance, and electrical properties by chemically bonding glass fibers and resin.

Examples of specific substances include 3-aminopropyltriethoxysilane and N-benzyltrimethylsilylamine.

3. Others

Applications of aminosilanes other than semiconductors and coupling agents include additives and primers for paints, adhesives, and coatings. They are useful as additives to phenolic resin binders and as additives to phenolic, furan, and melamine resins, which are foundry resins.

In the field of synthetic chemistry, it is sometimes used in synthetic materials, as are other organosilicon compounds.

Properties of Aminosilanes

3-Aminopropyltriethoxysilane (CAS No. 919-30-2), a typical aminosilane, has a molecular weight of 221.372, a melting point of -70°C, a boiling point of 119°C, and a liquid appearance at room temperature.

It has a density of 0.964 g/mL and a flash point of 96°C. It is soluble in water, ethanol, and acetone.

Types of Aminosilanes

Aminosilane compounds are mainly sold as R&D reagent products and silane coupling agents.

1. Reagent Products for Research and Development

Many substances are sold as reagent products for R&D, including 3-aminopropyltriethoxysilane and N-benzyltrimethylsilylamine, which are representative substances. They are available in volumes that are easy to handle in the laboratory. Depending on the substance, they are sold in relatively large volumes, such as 100g or 500g, or in smaller volumes, such as 1g or 5g. Normally, they are supposed to be stored in the dark.

2. Silane Coupling Agent

Aminosilane is sold in many products as an industrial silane coupling agent. Various types of packing and capacities are available, including 1 kg, 5 kg, 16 kg, 180 kg, 190 kg, and 950 kg. Typical substances include 3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, and 3-(N-phenyl)aminopropyltrimethoxysilane.

Other Information on Aminosilanes

Toxicological Information on 3-Aminopropyltrimethoxysilane

3-Aminopropyltriethoxysilane, a typical aminosilane, is a substance that is hazardous to the human body and is classified by the GHS classification as follows

• Acute toxicity (oral): Category 4
• Skin corrosion/irritation: Category 1
• Serious eye damage/eye irritation: Category 1
• Skin sensitization: Category 1
• Specific target organ systemic toxicity (single exposure): Category 3 (airway irritation, anesthetic effect)
• Specific target organ systemic toxicity (repeated exposure): Category 2 (respiratory)

When handling, appropriate local exhaust ventilation and general ventilation should be provided, and personal protective equipment such as protective clothing and protective goggles should be used.

What Is Anole?

Anole is one of the phenols represented by the structure of CH3-CH=CH-CH2-Ph-OH.

Other names include 4-(1-propenyl)phenol, β-methyl-p-hydroxystyrene, and 4-hydroxy-1-(1-propenyl)benzene.

In vitro, it is produced by heating anethole with potassium hydroxide.

In vivo, it is converted from trans-anole to trans-anethole by the action of phenylpropene O-methyltransferase (reversible reaction).

Uses of Anole

This protein is involved in the phenylpropanoid biosynthetic pathway, which is part of the metabolism of aromatic compounds and has important biochemical roles. The phenylpropanoid biosynthetic pathway (≈shikimic acid pathway) is a biosynthetic pathway for aromatic amino acids (phenylalanine, tyrosine, tryptophan) in plants and bacteria.

Note that the abbreviation “anole” is sometimes used to refer to cyclohexanol, an intermediate in nylon synthesis.

What Is Aniline Hydrochloride?

Aniline hydrochloride is an organic compound with the chemical formula C₆H₈ClN and is classified as an aromatic ammonium salt.

The CAS registration number is 142-04-1. Other names include aniline hydrochloride, benzeneamine hydrochloride, phenylamine hydrochloride, aniline chloride, aniline salt, and phenylammonium aniline chloride hydrochloride.

The name according to IUPAC nomenclature is anilinium chloride. Aniline hydrochloride is designated as a deleterious substance under the Poisonous and Deleterious Substances Control Law.

Uses of Aniline Hydrochloride

Aniline hydrochloride is mainly used as a raw material for dyes and organic synthesis. Aniline hydrochloride is known to oxidize to an insoluble black dye called aniline black, and this reaction is used to dye textiles.

In addition, the reaction of aniline hydrochloride with nitrous acid at temperatures below 5°C produces benzenediazonium chloride. This benzenediazonium chloride is a substance that causes diazo coupling when mixed with phenol salts.

The product of diazo coupling is a red-to-yellow dye, which is used for dyeing. Aniline hydrochloride is also a substance used as an intermediate in aniline synthesis.

Properties of Aniline Hydrochloride

Aniline hydrochloride has a molecular weight of 129.59, a melting point of 198°C, and a boiling point of 245°C (decomposition).

It turns dark when exposed to air and light. Its density is 1.22 g/mL and its solubility in water is 107 g/100 mL (at 20°C). It is soluble in ether and ethanol as well as water. It is insoluble in benzene.

Types of Aniline Hydrochloride

Aniline hydrochloride is sold mainly as a reagent product for research and development and as an industrial chemical. Potential applications for industrial chemicals include raw materials for pharmaceuticals, flux, and organic synthesis.

R&D reagent products are available in 25g, 100g, 500g, and other capacities. Generally, they are provided in capacities that are easy to handle in the laboratory. They are stored at refrigerated or room temperature.

Other Information on Aniline Hydrochloride

1. Synthesis of Aniline Hydrochloride

Aniline hydrochloride is obtained by adding concentrated hydrochloric acid to aniline. In the method of aniline synthesis in which nitrobenzene is reduced with tin and hydrochloric acid, the resulting aniline may react with excess hydrochloric acid to give aniline hydrochloride.

2. Chemical Reaction of Aniline Hydrochloride

Since aniline hydrochloride is a weak base, the addition of a strong base, such as sodium hydroxide, liberates aniline. Another important chemical reaction of aniline is the synthesis of benzenediazonium chloride.

The reaction of aniline hydrochloride with nitrous acid at temperatures below 5°C gives benzenediazonium chloride. Benzene diazonium chloride reacts with phenol salts in a diazo coupling reaction to give various diazo compounds. In general, diazo compounds are useful as dyes and dyestuffs.

3. Reactivity of Aniline Hydrochloride

Aniline hydrochloride is stable under normal handling conditions, but is flammable and decomposes upon heating or contact with acids. It reacts vigorously, especially with oxidizing agents, producing toxic and corrosive fumes containing aniline, nitrogen oxides, and hydrogen chloride. 

4. Aniline Hydrochloride Hazard and Regulatory Information

Aniline hydrochloride is classified by the GHS classification as having the following hazards

• Acute toxicity (oral): Category 4
• Germ cell mutagenicity: Category 2
• Carcinogenicity: Category 1B
• Reproductive toxicity: Category 2
• Specific target organ toxicity (single exposure): Category 1 (blood system, nervous system)
• Specific target organ toxicity (repeated exposure): Category 1 (blood system, nervous system)

Due to these hazards, aniline hydrochloride is classified as a deleterious substance under the Poisonous and Deleterious Substances Control Law. It is important to handle it correctly in compliance with the law.