4-Hydroxy (methoxy) benzaldehyde, although it did not have this exact chemical name in the era covered by "Tiangong Kaiwu", it also had many important uses at that time in terms of similar substances.
In the dyeing and weaving industry, it can be used as a dye aid. At that time, dyers wanted a bright and long-lasting color, and often looked for natural or synthetic additives to assist. 4-Hydroxy (methoxy) benzaldehyde has a certain chemical activity, or can be combined with fabric fibers to enhance dye adsorption and fixation, making dyeing more uniform and firm, helping craftsmen dye a brilliant color like Suhang satin.
In the field of fragrance production, this substance is of great significance. The ancients pursued a high degree of aroma, and its unique smell can add a unique flavor to the fragrance.
Furthermore, in terms of medicine, traditional medicine attaches great importance to the medicinal use of natural substances. 4-Hydroxy (methoxy) benzaldehyde may have certain pharmacological activity. After traditional processing and compatibility, it can regulate human qi and blood and relieve discomfort. For example, in ancient Langzhong or in the exploration, it was found that drugs containing such ingredients were effective for some diseases. Although there was no modern precise pharmacological cognition, they played their medicinal value by accumulating experience.
In addition, in the preservative process of some traditional handmade products, it may play a role. For example, the production of high-grade paper, calligraphy and painting mounting, etc., in order to prevent moths and preservatives, the use of preparations containing this ingredient can prolong the storage time of products, so that precious calligraphy, painting and ancient books can be passed down for a long time.

4-Cyanogen (cyanomethyl) quinoline, this physical property is strange and worth exploring.
Its color state is often white or yellowish powder, the texture is delicate, and it looks shiny, like a fine pearl. Under normal temperature and pressure, it exists stably, like a lying stone, and does not change easily.
When it comes to the melting point, the melting point is about a specific range. When the temperature rises to this point, it is like ice melting in spring, gradually turning from solid to liquid. The boiling point also has its own number, and when it reaches this high temperature, it will turn into gas and rise.
In terms of solubility, in some organic solvents, such as alcohols and ethers, it can quietly disperse, just like salt melts in water and fuses with the solvent, but in water, it is difficult to find its trace, just like oil falls in water and floats alone.
Furthermore, its density is different from common substances. When held in the hand, it feels light or heavy, depending on its purity and the environment.
In terms of stability, under normal circumstances, it can maintain its original state and does not easily combine with surrounding substances. In case of strong acids and alkalis, or extreme conditions of high temperature and high pressure, it will react instantaneously when it encounters dry wood from a hot fire, generating something different, and its properties will completely change.
As for toxicity, it must not be underestimated. If you accidentally touch or inhale its dust, it may be harmful to human health, like a hidden arrow, quietly hurting people. Therefore, when using it, you must be cautious and strictly follow the procedures to prevent accidents.

The chemical properties of 4-% hydrazine (cyanomethyl) ether are quite stable. In its structure, nitrogen atoms are connected to carbon atoms to form a relatively stable structure.
Looking at its chemical properties, this substance is not prone to violent reactions in many common chemical environments. Under normal temperature and pressure, it can maintain its own structure intact for a long time without obvious decomposition or deterioration.
In organic solvents, 4-% hydrazine (cyanomethyl) ether exhibits a certain solubility, but its solubility is also restricted by solvent properties. In polar organic solvents, such as alcohols and ketones, it can be moderately dissolved; in non-polar solvents, the solubility is relatively limited.
When it comes to reactivity, although its structure is relatively stable, it can still participate in some chemical reactions under certain conditions. For example, in the presence of a catalyst, suitable temperature and pressure environment, it can react with some nucleophiles, and the cyanomethyl part or the hydrogen atom on the nitrogen atom can be replaced to form new compounds. However, such reactions require precise control of the reaction conditions in order to proceed smoothly, which shows that it has certain chemical stability.
In addition, 4-% hydrazine (cyanomethyl) ether also has a certain tolerance to acid-base environments. In weakly acidic or weakly alkaline media, the chemical properties do not change significantly for a short time. Only under the action of strong acid and alkali for a long time, its structure may be damaged and hydrolysis and other reactions occur, but this also indicates that the chemical properties of the substance are stable under common acid and alkali conditions.

To prepare tetrahydroxy (hydroxymethyl) furfural, the methods are as follows:
First, choose the appropriate raw materials. Usually start with carbohydrate-rich substances, such as sugars, monosaccharides such as glucose and fructose, and polysaccharides such as sucrose and starch. Because sugars can be converted into this substance through a series of reactions. If fructose is used, its structure makes the conversion easier and can improve the yield.
Second, choose a suitable catalyst. Acid catalysts are quite commonly used, such as inorganic acids (sulfuric acid, hydrochloric acid, etc.), which can promote the reaction, reduce the activation energy of the reaction, and increase the reaction rate. However, it has strong corrosion to equipment. There are also solid acid catalysts, such as sulfonic acid ion exchange resins, which are easy to separate and reusable, and can reduce damage to equipment. In addition, metal salt catalysts can also be used, such as chromium salts, zinc salts, etc., which can efficiently catalyze this reaction under specific conditions.
Third, control the appropriate reaction conditions. The temperature is very critical, generally between 100 and 200 ° C. Low temperature, slow reaction, low yield; high temperature, increased side reactions, and reduced product selectivity. The reaction time also needs to be accurately controlled, depending on the raw materials and catalysts, usually hours to ten hours. In addition, the choice of reaction solvents is also heavy. Polar organic solvents, such as dimethyl sulfoxide, N, N-dimethylformamide, etc., are used as soluble raw materials and catalysts to facilitate mass and heat transfer in the reaction.
Fourth, adopt a suitable separation and purification method. After the reaction, the product contains impurities and needs to be separated and purified. Distillation can be used first to steam out some low-boiling impurities according to the difference in boiling point of each component. After that, an extraction method is used to select a suitable extractant to improve the purity of the target product. Column chromatography can also be used to separate the product from impurities by means of a fixed phase and a mobile phase to obtain high-purity tetrahydroxy (hydroxymethyl) furfural.

In the storage and transportation of 4-hydroxymethyl furfural, the following matters should be paid attention to:
First, temperature control is essential. This substance is quite sensitive to temperature, and high temperature is easy to cause it to decompose or deteriorate. Therefore, when storing, it should be placed in a cool place, and the warehouse temperature should be strictly controlled below 25 ° C. During transportation, it is also necessary to avoid direct sunlight and close to heat sources. If it is transported during the high temperature season in summer, refrigerated transportation tools should be used to maintain its stability.
Second, moisture resistance should not be ignored. 4-hydroxymethyl furfural has certain hygroscopicity, and the quality is easily affected after being damp. The storage environment must be kept dry, and the humidity should be controlled below 60%. The packaging should be tight, often sealed barrels or sealed bags to prevent the intrusion of external water vapor. During transportation, the carriage should also be kept dry, and a desiccant can be placed if necessary.
Third, anti-oxidation needs to be treated with caution. The substance is easily oxidized in the air, thereby changing its chemical properties. When storing, it can be filled with inert gases such as nitrogen to isolate the air and inhibit the oxidation process. The transportation package should also minimize contact with air, and the transportation time should not be too long, and it should be delivered to the destination as soon as possible.
Fourth, avoid contact with incompatible substances. 4-Hydroxy (hydroxymethyl) furfural cannot be stored or transported together with strong oxidants, strong alkalis and other substances. Because of its encounter with strong oxidizing agents, it is easy to cause violent chemical reactions, and even the risk of explosion; contact with strong alkalis will also cause chemical reactions, resulting in its failure. Before storage and transportation, be sure to clarify the chemical properties of other substances in contact with it to prevent danger.
Fifth, storage and transportation equipment should be dedicated. In order to prevent cross-contamination, storage and transportation of 4-hydroxymethyl (hydroxymethyl) furfural equipment should be dedicated, and it should be thoroughly cleaned and dried before and after use to avoid residual other substances affecting its quality.