"Tiangong Kaiwu" says: "2 + -Jiang-4-cyanoacetohydrazide is an organic compound. Its properties are diverse.
Looking at its physical properties, it is mostly white or off-white crystalline powder under normal conditions, with fine quality. It can be slightly soluble in water, but it has a slightly better degree of solubility in organic solvents such as ethanol and acetone. Its melting point is in a specific range, so that it can be identified as pure hetero.
When it comes to chemical properties, cyanoacetohydrazide has cyano and hydrazine groups, both of which are active groups. Cyanyl groups can cause nucleophilic addition reactions, and can combine with many electrophilic reagents to form different organic structures. Hydrazine groups are highly reducible. Under suitable conditions, they can react violently with oxidants, and can also participate in condensation reactions. They interact with compounds such as aldodes and ketones to produce nitrogen-containing heterocyclic substances.
And because there are active hydrogen atoms in its structure, it can complex with metal ions to form a stable complex, which is quite useful in some chemical processes and analytical assays. It is widely used in the field of organic synthesis. It can be a key intermediate. After a series of reactions, a variety of fine chemicals such as drugs, pesticides, and dyes can be prepared. However, this substance is also toxic to a certain extent. When used and stored, it should be strictly regulated to prevent harm to people and the environment. "

"Tiangong Kaiwu" says: "Mercury is natural but does not coagulate, and soars in case of fire. It is a material, like silver and flowing, like water and strong." 2 + -Mercury-4-aminobenzoate ethyl ester, among which mercury is a chemical substance, its physical properties are unique.
Mercury is liquid at room temperature, and is the only liquid metal. Its appearance is silver-white and shiny, just like flowing silver, with a dazzling luster. Its fluidity is very good, it drops on the plane, rolls freely, and is difficult to condense. And it has a high density and feels heavy. If it is held in a container, it can feel that its weight is different from that of normal liquid.
The melting point of mercury is extremely low, only -38.87 ° C, and it turns into a flowing state when heated. The boiling point is also not high, at 356.6 ° C. It is volatile when heated and turns into mercury vapor. This mercury vapor is colorless and odorless, but it is toxic. It is invisible and easy to be ignored by the world, but it is very harmful.
The surface tension of mercury is quite high. It drops on the plane and often aggregates into a bead shape, similar to mercury beads. It is round and smooth. Its thermal conductivity is good, and it is also considerable among many metals.
As for ethyl 4-aminobenzoate, it is a white crystalline powder, odorless and slightly bitter in taste. Melting point of about 91-94 ℃, insoluble in water, soluble in ethanol, ether and other organic solvents. Its properties are stable, at room temperature and pressure, not easy to react with common substances.

"Tiangong Kaiwu" has a saying: "Where gunpowder, sulfur is pure yang, nitrate is pure yin, and the two essences are forced together to form sound and change, and this universe hallucinates a god." And "sulfur-sulphur-4-nitrobenzene, methyl ether" and other substances, although their main uses are not directly mentioned in many ancient books, they can be deduced from today's scientific understanding combined with ancient chemical principles.
Sulfur was mostly used in alchemy and pharmaceuticals, metallurgy and gunpowder production in ancient times. In gunpowder, sulfur provides a combustible material, laying the foundation for violent reactions. As recorded in the gunpowder formula in the "Remarks", sulfur is the key ingredient.
Saltpeter was also an important chemical raw material in ancient times. It appeared frequently in alchemy and could provide oxygen in gunpowder, causing gunpowder to burn violently. The "Compendium of Materia Medica" has many records on its properties and uses.
"Nitroanisole" Although rare in ancient literature, if anisole substances contain nitro groups, from the perspective of modern chemistry, nitro groups have strong oxidizing properties, or can be used in the field of organic synthesis. Analogous to ancient times, it may participate in some violent reaction systems like saltpeter, providing a special chemical environment for the reaction. And because its structure contains benzene rings, or can be used to make special fragrances and dye precursors. In ancient times, the production of fragrances and dyes was related to people's livelihood and trade. If this substance was available at that time, it might play a unique role in these fields, creating different aromas or colors with its special structure.
However, the ancient chemical technology was limited, and it was difficult to precisely prepare and utilize such complex organic substances, but its principles and the spirit of exploring material properties are the same in ancient times and modern times.

To prepare ethyl 2-hydroxy-4-aminobutyrate, the methods are as follows:
First, gamma-butyrolactone is used as the starting material. First, the alcoholysis reaction of gamma-butyrolactone and ethanol under acid catalyst can obtain ethyl 4-hydroxybutyrate. Then, 4-hydroxybutyrate ethyl ester is reacted with ammonia under appropriate conditions, and the hydroxyl group is replaced by the amino group to obtain 2-hydroxy-4-aminobutyrate ethyl ester. The raw materials are common in this way, and the steps are still simple, but the ammonolysis step may require strict conditions and special equipment. The reaction is roughly as follows: γ-butyrolactone + ethanol (acid catalyst) → ethyl 4-hydroxybutyrate, ethyl 4-hydroxybutyrate + ammonia → ethyl 2-hydroxy-4-aminobutyrate.
Second, start with 2-bromo-4-nitrobutyrate ethyl ester. First, 2-bromo-4-nitrobutyrate ethyl ester is converted to amino group by a suitable reducing agent such as iron and hydrochloric acid or catalytic hydrogenation method to obtain 2-bromo-4-aminobutyrate ethyl ester. Then treated with alkali solution, the bromine atom is replaced by a hydroxyl group, and the final product is obtained. The reaction steps of this diameter are relatively easy to control, but the raw material 2-bromo-4-nitrobutyrate ethyl ester may be difficult to prepare. The reaction process is: 2-bromo-4-nitrobutyrate ethyl ester + reducing agent → 2-bromo-4-aminobutyrate ethyl ester, 2-bromo-4-aminobutyrate ethyl ester + base → 2-hydroxy-4-aminobutyrate ethyl ester.
Third, the diethyl malonate method is adopted. Diethyl malonate is first reacted with haloethanol under the action of alkali to introduce hydroxyl-containing side chains. Then 4-hydroxybutyric acid is obtained by hydrolysis and decarboxylation. Then 4-hydroxybutyric acid is esterified to 4-hydroxybutyrate ethyl ester, and finally the amino group is introduced by reaction with ammonia. This step is slightly complicated, but the selectivity of each step is good, and the product purity is higher. The series of reactions are: diethyl malonate + halogenated ethanol (base) → hydroxyl side chain products, hydrolyzed and decarboxylated → 4-hydroxybutyric acid, 4-hydroxybutyric acid + ethanol (esterification) → 4-hydroxybutyrate ethyl ester, 4-hydroxybutyrate ethyl ester + ammonia → 2-hydroxy-4-aminobutyrate ethyl ester.

In the storage and transportation of 2 + -Jiang-4-aminobenzoate, the following things should be paid attention to:
First, the control of temperature is crucial. This substance is quite sensitive to temperature, and excessive temperature can easily cause its chemical properties to change, or it may decompose or deteriorate. Therefore, it is recommended to maintain a cool and constant temperature in the storage place, usually 2-8 ° C. In this way, the quality can be guaranteed to be stable and the storage period can be extended.
Second, the influence of humidity should not be underestimated. High humidity environment easily makes 2 + -Jiang-4-aminobenzoate hygroscopic, which in turn affects its purity and stability. In the storage place, when kept dry, a desiccant can be placed next to it to absorb excess water vapor and avoid the worry of moisture.
Third, light will affect it. If the substance is exposed to light for a long time, especially strong direct light, it is easy to cause photochemical reactions and damage its quality. Therefore, when storing, it should be protected from light or packed in an opaque container to protect it from light.
Fourth, when transporting, it is necessary to ensure that the packaging is intact. This substance has a certain chemical activity. If the packaging is damaged or reacts in contact with external substances, it will not only endanger the safety of transportation but also damage its quality. Therefore, the packaging material should be solid and well sealed to resist bumps and collisions during transportation.
Fifth, 2 + -Jiang-4-aminobenzoate ethyl ester may be toxic, and relevant safety regulations must be followed during storage and transportation. Staff should wear protective equipment to avoid direct contact, and storage and transportation places should be well ventilated to prevent the accumulation of harmful gases and ensure the safety of personnel and the environment.