3-Pyridinecarboxaldehyde,5-methoxy-

The physical properties of 3-pentyne, 5-methyl-ethynyl are as follows:
###3-pentyne
1. ** Appearance and odor **: At room temperature and pressure, 3-pentyne is usually a colorless liquid with a special odor similar to acetylene. Because its molecular structure contains carbon-carbon triple bonds, the existence of this unsaturated bond makes it have a certain characteristic odor, which is significantly different from the odor of saturated hydrocarbons.
2. ** Boiling point **: The boiling point is about 39 ° C. The boiling point is relatively low, which is mainly due to its intermolecular forces. 3-Pentyne mainly has a weak van der Waals force between molecules. Compared with compounds with stronger intermolecular forces (such as hydrogen bonds), it requires less energy to overcome the attraction between molecules, thus changing from liquid to gaseous, so the boiling point is lower.
3. ** Melting point **: The melting point is about -90 ° C. The lower melting point is also related to the intermolecular force. In a low temperature environment, the thermal motion of molecules is weakened. When the temperature is reduced to a certain extent, the relative position between molecules is fixed, and the substance changes from liquid to solid. 3-Pentyne The intermolecular force is not strong, so that it can solidify at relatively low temperatures.
4. ** Solubility **: Slightly soluble in water, easily soluble in organic solvents, such as ethanol, ether, benzene, etc. This is because 3-pentyne belongs to non-polar or weakly polar molecules. According to the principle of "similar miscibility", it has good compatibility with non-polar or weakly polar organic solvents. Water is a solvent with strong polarity. The interaction between it and 3-pentyne molecules is weak, resulting in its low solubility in water.
5. ** Density **: The density is less than that of water, about 0.69 g/cm ³. Its molecular relative mass is small, and the intermolecular arrangement is relatively loose, so that the mass per unit volume is less than that of water, so it will float on the water surface.
###5 -methyl-ethynyl
1. ** Appearance **: 5-methyl-ethynyl is not an independent stable substance, it is usually used as a structural fragment in organic compounds. If the common organic compounds containing this structural fragment are taken into account, due to the different complexity of the structure, the appearance may be diverse, which may be liquid or solid. But in general, due to the presence of unsaturated acetynyl groups in its structure, such compounds often have a certain characteristic appearance of unsaturated compounds. For example, some liquids may appear clear and transparent.
2. ** Related properties **: Due to the presence of ethynyl groups, compounds containing 5-methyl-ethynyl structures have higher reactivity. Indirectly reflected in physical properties, for example, in solubility, similar to 3-pentyne, due to the non-polarity of ethynyl groups and methyl groups, compounds containing this structure are generally soluble in organic solvents. At the same time, in terms of boiling point and melting point, it will be affected by the entire molecular structure, but unsaturated ethynyl groups will cause intermolecular forces to be different compared to saturated structures, generally reducing the degree of compactness between molecules, which will affect the melting boiling point. Usually, the melting boiling point is not too high, but the specific value needs to be accurately determined according to the overall molecular structure.

3-Aminopentanitrile and 5-amino-pentanol, both of which are organic compounds, each with unique chemical properties.
Let's talk about 3-aminopentanitrile first, which contains cyano (-CN) and amino (-NH2O) in its molecules. Cyano has high reactivity and is prone to hydrolysis. Under acid or base catalysis, cyano can be gradually converted into carboxyl (-COOH) to generate 3-aminopentanoic acid. This reaction is often used in organic synthesis to construct carboxylic acid compounds. At the same time, amino groups are basic and can neutralize with acids to form corresponding salts. For example, when reacted with hydrochloric acid, 3-aminopentanitrile hydrochloride can be formed. In addition, the amino group can also participate in the nucleophilic substitution reaction. When it encounters the halogenated hydrocarbon, the nitrogen atom in the amino group will attack the carbon atom of the halogenated hydrocarbon, and the halogen atom will leave, thus forming a new carbon-nitrogen bond, which realizes the modification and expansion of the molecular structure.
Looking at 5-aminopentanol, this compound has both a hydroxyl group (-OH) and an amino group in the molecule. The presence of the hydroxyl group makes it have the typical properties of alcohols, and it can undergo esterification reaction. Under the catalysis of concentrated sulfuric acid and heating conditions, it can react with carboxylic acids to form esters and water, such as 5-aminopentyl acetate. Hydroxyl groups can also be oxidized, and can be oxidized to aldehyde (-CHO) or carboxyl groups depending on the strength of the oxidi Amino groups can also exhibit alkalinity and react with acids to form salts. Not only that, amino groups and hydroxyl groups may also undergo intramolecular or intermolecular condensation reactions to form cyclic or chain-like polymers, which is of great significance in the synthesis of some polymer materials with special structures.

3-Alkyl, 5-amino-pentanoic acid, both of which have important uses in many fields.
Let's talk about 3-alkyl first, which plays a key role in the field of organic synthesis. Alkyl groups can act as key structural fragments when building complex organic molecular architectures. For example, in the process of preparing natural product analogs with specific physiological activities, the introduction of suitable 3-alkyl groups can effectively adjust the spatial configuration and electron cloud distribution of molecules, thereby significantly changing the physical, chemical and biological activities of the compound. In the field of polymer material synthesis, 3-alkyl groups, as side chain structures, can greatly affect the properties of polymer polymers, such as solubility, thermal stability and mechanical properties. When the carbon chain length and degree of branching of the 3-alkyl group change, the glass transition temperature and crystallization properties of the polymer will also change, making the material suitable for application needs in different scenarios.
As for 5-amino-valeric acid, in the field of biochemistry, it is a key intermediate for the synthesis of a variety of biologically active substances. For example, in the synthesis of certain neurotransmitter analogs, 5-amino-valeric acid can be used as a starting material to construct compounds similar in structure to natural neurotransmitters through a series of chemical reactions, providing an important material basis for the study of neurotransmission mechanisms and the development of neurological drugs. In the field of medicine, 5-amino-valeric acid participates in the synthesis of drugs, some can be used to regulate human metabolism, and some have a certain corrective effect on metabolic disorders caused by certain diseases. At the same time, in materials science, 5-amino-valeric acid can be used to prepare functional materials, such as its polymerization with specific monomers, which can generate polymer materials with biocompatibility and amino activity check points, and show good application prospects in biosensors, drug sustained-release carriers, etc.

To prepare 3-alkylpentanitrile and 5-aminopentanitrile, the method is as follows:
The preparation of 3-alkylpentanitrile can be obtained by reacting 3-halopentane and sodium cyanide in a suitable solvent at an appropriate temperature. The halogen atom of halopentane has high activity, and the cyanyl group in sodium cyanide has strong nucleophilicity. When the two meet, the halogen atom is replaced by a cyanyl group, so 3-alkylpentanitrile is obtained. For example, 3-bromopentane and sodium cyanide are heated in an ethanol solution and refluxed. After a period of reaction, after separation and purification, pure 3-alkylpentanitrile can be obtained. The method of separation can first remove the solvent by distillation, and then use column chromatography to separate the unreacted raw materials and products for the purpose of purification.
As for the preparation of 5-aminovaleronitrile, glutaric anhydride can be reacted with ammonia to obtain glutaramide. Glutaric anhydride has the activity of acid anhydride, and ammonia is a nucleophilic agent. The two react to form glutaramide. Then, glutaramide and sodium hypobromite solution are subjected to Hoffman degradation reaction under basic conditions. In this reaction, the amide group is rearranged under the action of sodium hypobromite and base, and the carbonyl group is decarbonylated to form a primary amine with one less carbon atom, namely 5-aminovaleronitrile. After the reaction is completed, the pH value of the reaction solution is adjusted to neutral, the product is extracted with organic solvent, and then the solvent is removed by distillation for further purification, and the pure product of 5-aminovaleronitrile can be obtained. In this way, the required 3-alkyl valeronitrile and 5-aminovaleronitrile can be obtained.

3 - to its methyl ether, 5 - methoxy - In storage and transportation, many matters need to be paid attention to. Both are chemical substances. The storage and transportation of chemical substances are related to safety, quality and many other key aspects, and should not be ignored.
Let's talk about storage first. First, it needs to be placed in a cool and well-ventilated place. Because it may be volatile, high temperature is prone to increased volatilization, or even cause danger. And good ventilation can avoid gas accumulation and reduce latent risk. Second, keep away from fires and heat sources. Such substances are flammable, and they are easily flammable and explosive in case of open flames and hot topics. Therefore, fireworks are strictly prohibited in storage places, and electrical equipment should also meet explosion-proof requirements. Third, it should be stored separately from oxidizing agents, acids, etc. Due to the active chemical properties of 3-dimethyl ether and 5-methoxy group, contact with oxidizing agents, acids, etc., or violent chemical reactions occur, resulting in dangerous conditions. Fourth, the storage container must be well sealed. To prevent its leakage, one is to avoid material loss, and the other is to prevent harm to the environment and people after leakage.
As for transportation, the first heavy packaging. The packaging material must be strong and sealed, and can withstand certain pressure and vibration to prevent damage and leakage during transportation. Transportation vehicles should also meet safety standards and be equipped with corresponding fire-fighting equipment and leakage emergency treatment equipment. During transportation, the speed should not be too fast, so avoid sudden braking to prevent packaging damage due to collisions and bumps. And transport personnel must be professionally trained, familiar with the nature of the transported substances and emergency treatment methods. In case of leakage, corresponding measures should be taken immediately to evacuate the crowd and prevent the expansion of the accident.
In short, when storing and transporting 3-dimethyl ether and 5-methoxy, every detail is related to safety, and must strictly follow the relevant regulations and requirements and be treated with caution.