1,3-dibromopropane is a crucial raw material in organic synthesis. Although it is not directly mentioned in "Tiangong Kaiji", its main use can be known from the development of ancient chemical processes and the concept of organic synthesis.
In the field of organic synthesis, 1,3-dibromopropane can be used as a key intermediate. Because the bromine atom in the molecule has high reactivity, it can be substituted with many nucleophiles. For example, it can react with nucleophiles such as alkoxides and amines to form various carbon-heteroatomic bonds, thereby synthesizing organic compounds with diverse structures. Considering the organic synthesis in ancient times, although the technology and understanding at that time were not as good as today, such reaction principles may have been applied in some simple organic synthesis. For example, in the process of preparing specific fragrances and medicinal ingredients, or with the help of intermediates such as 1,3-dibromopropane, through ingenious chemical reactions, to achieve the synthesis of desired compounds.
In addition, 1,3-dibromopropane may have potential uses in material modification. In ancient times, although there was no modern advanced material science, in fabrics, leather and other treatment processes, or try to use it to participate in the reaction to change the surface properties of materials. Because bromine atoms can introduce polar groups, or improve the hydrophilicity and antistatic properties of materials. For example, in the process of fabric dyeing, 1,3-dibromopropane may participate in some pretreatment steps to make the fabric more easily adsorbed dyes, thereby improving the dyeing effect and fastness.
Furthermore, in the preparation of fine chemical products, 1,3-dibromopropane may also play an important role. Although the concept of fine chemical in ancient times was not as clear as it is today, in the preparation of products such as special oils and waxes, 1,3-dibromopropane or as a reaction raw material, through a specific reaction path, to generate fine chemical products with special properties to meet the specific needs of life and production at that time.

1,3-Dibromopropane is an organic compound, and its physical properties are as follows:
Under normal temperature and pressure, 1,3-dibromopropane is a colorless to light yellow transparent liquid, which visually presents a clear, impurity-free state and has a certain fluidity. Its color is pure, and there is no obvious variegation or turbidity.
Smell it, it has a special irritating odor. This odor is quite strong. If you smell it closely, it can stimulate the sense of smell. This irritating odor is given by the chemical structure of the substance, and you need to pay attention when actually touching and handling it.
Touch it, its density is higher than that of water, about 2.02g/cm ³. Touching a container containing 1,3-dibromopropane with your hand will perceive it to be heavier than a container of the same volume of water. It will sink to the bottom in water due to density differences.
Measured, the boiling point is about 167 ° C. Under normal pressure, when 1,3-dibromopropane is continuously heated to 167 ° C, the substance will change from liquid to gaseous and begin to boil and evaporate. The melting point is about -34 ° C, that is, in an environment below -34 ° C, 1,3-dibromopropane will solidify from liquid to solid. In addition, 1,3-dibromopropane is slightly soluble in water and has a low solubility in water. When dropped into water, it will disperse in water in the form of droplets, making it difficult to mix uniformly with water, but it can be miscible with organic solvents such as ethanol and ether. It can dissolve with these organic solvents in any proportion to form a uniform and stable solution system.

1% 2C3-dibromopropane is also an organic compound. Its properties are as follows:
Looking at its shape, it is a colorless to light yellow transparent liquid under normal circumstances. It smells like chloroform and is volatile.
In terms of its solubility, it can be soluble in most organic solvents, such as ethanol, ether, acetone, etc., but almost insoluble in water.
Its chemical properties are active, and it is prone to substitution reactions due to the presence of bromine atoms. Under appropriate conditions, bromine atoms can be replaced by other atoms or groups, such as hydroxyl groups, amino groups, etc. This property makes it widely used in the field of organic synthesis. At the same time, in a strong alkali environment, elimination reactions can occur to form unsaturated hydrocarbon compounds.
Furthermore, 1% 2C3-dibromopropane is flammable, can burn in open flames and hot topics, and emits toxic fumes containing bromine when burned. Due to the existence of carbon-bromine bonds in its chemical structure, the compound is relatively stable, but it can exhibit active reactivity under specific chemical reaction conditions, so it is often used as an intermediate in the organic synthesis industry, providing an important starting material for the preparation of various organic compounds.

The preparation method of 1,3-dibromopropane is to add propylene and hydrogen bromide to obtain 1-bromopropane, and then react 1-bromopropane with bromine under light or heating conditions to obtain 1,3-dibromopropane. The steps are as follows:
First take an appropriate amount of propylene, place it in a suitable reaction vessel, and introduce hydrogen bromide gas. Propylene has unsaturated double bonds and can be added to hydrogen bromide. This reaction follows the Markov rule. Hydrogen atoms are added to double-bonded carbon atoms containing more hydrogen, and bromine atoms are added to double-bonded carbon atoms containing less hydrogen to generate 1-bromopropane. The chemical reaction equation is: $CH_2 = CHCH_3 + HBr\ longrightarrow CH_3CH_2CH_2Br $.
The obtained 1-bromopropane is placed in an environment with sufficient light or heating, and an appropriate amount of bromine is added. At this time, the hydrogen atom on the ortho-carbon atom of the carbon atom connected to the bromine atom in the 1-bromopropane molecule is enhanced by the influence of the bromine atom. Under light or heating conditions, the bromine molecule is split into bromine radicals, and the bromine radicals attack the hydrogen atom on the ortho-carbon atom of 1-bromopropane, triggering a free radical substitution reaction to generate 1,3-dibromopropane. The chemical reaction equation is: $CH_3CH_2CH_2Br + Br_2\ xrightarrow {light or heat} CH_2BrCH_2CH_2Br + HBr $.
This is a common preparation method of 1,3-dibromopropane. By reasonably controlling the reaction conditions and the ratio of raw materials, a higher yield product can be obtained.

When storing and transporting 1% 2C3-dibromopropane, all kinds of precautions are very important.
When storing, the first warehouse conditions. A cool and ventilated warehouse must be selected, away from fire and heat sources. Because 1% 2C3-dibromopropane is flammable, if it encounters an open flame or hot topic, it is easy to cause the risk of combustion and explosion. The warehouse temperature should be controlled within a suitable range to prevent its volatilization from intensifying or chemical reaction due to excessive temperature.
Furthermore, storage should be separated from oxidants, acids, alkalis, etc., and should not be mixed. Because of its active chemical nature, contact with these substances or react violently, endangering safety. And the warehouse should be equipped with suitable containment materials to prevent accidental leakage and deal with it in time to reduce the harm.
When transporting, do not slack off. The transportation vehicle must be equipped with the corresponding variety and quantity of fire fighting equipment and leakage emergency treatment equipment. Summer transportation should be selected in the morning and evening to avoid the hot sun to prevent the pressure inside the vehicle from increasing due to the increase in temperature and causing danger.
During transportation, make sure that the container does not leak, collapse, fall or damage. The speed should not be too fast, and avoid sudden braking to prevent the goods from colliding and being damaged, resulting in the leakage of 1% 2C3-dibromopropane. And the transportation process should be kept away from sensitive areas such as densely populated areas and water sources to reduce the impact on the public and the environment in the event of an accident. Escort personnel must be fully supervised and familiar with emergency handling methods. In the event of an emergency, they can respond promptly and properly to ensure transportation safety.