2-Bromo-3-methyl-5-chloropyridine

Although 2-% arsine-3-methyl-5-mercaptopyridine did not exist in the era mentioned in "Tiangong Kaiwu", its use can be deduced from the perspective of ancient classical Chinese, or it can be discussed from the properties of similar substances and traditional process ideas.
In the field of alchemy and pharmaceuticals, traditional alchemy is often involved in the refining of gold and stone medicines. Substances containing arsenic, sulfur and other elements have many applications. 2-% arsine-3-methyl-5-mercaptopyridine contains arsenic (arsenyl) and sulfur (thiol) related structures, and alchemists may be interested in it. Arsenic compounds were sometimes regarded as raw materials that could be "enchanted" and pursue longevity in ancient alchemy. Although there was no scientific basis for this understanding, from the tradition of alchemy, they might try to incorporate them into the alchemy process to explore whether they could refine the so-called "magic pill".
In metallurgy and metal processing, ancient times had some knowledge of the reaction between metals and sulfur-containing and arsenic-containing substances. Some sulfides and arsenides can participate in the reaction during metal smelting and affect the properties of metals. For example, in ancient copper smelting, the appropriate sulfur content can adjust the fluidity of copper liquid. If 2-% arsenic-3-methyl-5-mercaptopyridine is introduced into metallurgy, the sulfur and arsenic components may react with metals in a complex manner, changing the texture and color of metals. It may be used to make alloys of special colors or properties to meet the needs of process decoration or special utensils manufacturing, such as the manufacture of unique color cauldrons, weapons, etc.
From the perspective of agriculture and insect control, some sulfur and arsenic-containing substances were known to have insect repellent and antiseptic effects in ancient times. For example, realgar (containing arsenic) is used to repel insects and ward off evil spirits, and lime sulfur mixture is used for insect control of fruit trees. The sulfur and arsenic structure of 2-% arsine-3-methyl-5-mercaptopyridine may make it have similar insect repellent and antibacterial properties. The ancients may try to use it for storage and insect control to protect grain; or for smearing trees to prevent pests and ensure agricultural production and material preservation.

To prepare 2-bromo-3-methyl-5-nitropyridine, you can follow the following ancient methods.
First, take an appropriate amount of pyridine as the base, add a specific catalyst in a suitable reactor, control the temperature in a certain range, and slowly introduce brominating reagents. This process requires careful attention to the process of the reaction. Due to the different activities of hydrogen atoms on the pyridine ring, bromine atoms tend to replace hydrogen at a specific position. After this operation, bromine-containing pyridine derivatives can be obtained. Then, the resulting product is separated and purified to achieve higher purity.
Next, move the purified bromopyridine derivative to another reaction vessel, add a methylating reagent, and react in an alkaline environment and at an appropriate temperature. This step aims to introduce methyl at a suitable position. The amount of methylating reagent and reaction conditions must be precisely controlled, otherwise side reactions will easily occur. After the reaction is completed, the method of separation and purification is carried out to obtain 2-bromo-3-methylpyridine.
Finally, take 2-bromo-3-methylpyridine and place it in a strong nitrifying environment. Usually, a mixed acid of concentrated nitric acid and concentrated sulfuric acid is used as the nitrifying reagent. During the reaction, the temperature and reaction time are strictly controlled, because the introduction of nitro groups will change the electron cloud density of the pyridine ring and affect the subsequent reaction. After nitration, the product is separated and refined to obtain 2-bromo-3-methyl-5-nitropyridine.
Second, pyridine can be methylated first, then brominated, and finally nitrified. That is, pyridine is first reacted with methylating reagents under specific conditions to obtain 3-methylpyridine. After separation and purification, it is reacted with brominating reagents to obtain 2-bromo-3-methylpyridine, and finally nitrified to obtain the target product.
No matter what method is used, each step of the reaction requires attention to the precise control of the reaction conditions, and the operation of separation and purification is also crucial, which is related to the purity and yield of the final product.

2-% hydroxyl-3-methyl-5-nitropyridine This substance is strong and active, and it is unique among all chemical lines.
Its color is often light yellow, or crystalline, or in the shape of powder. It looks like normal, but it contains heterogeneity. Its melting degree is quite high, about [X] degrees Celsius, and it melts when heated. It is like mercury flowing out, but it is not smooth like water, but has a strong state. The boiling point is also extraordinary. It boils to [X] degrees Celsius and turns into gas. However, the gas has a pungent smell and is uncomfortable to smell.
When it comes to solubility, it is difficult to dissolve in water, such as stone sinking into the abyss, and cannot be melted. However, in organic solvents, such as alcohols and ethers, it can gradually dissolve, like ice and snow melting with warmth, and fuse into one. This property makes it participate in various chemical reactions with organic solvents as a medium.
Chemical activity is particularly strong, the presence of nitro groups makes it oxidizing, just like fire, it can combine with many reducing agents, causing violent changes. Methyl and hydroxyl groups also show their own abilities. Hydroxyl groups are hydrophilic, and can also be esterified with acids, such as silk threads intertwined to form new compounds. Methyl groups affect the spatial structure of their molecules and the distribution of electron clouds, making their reactivity and selectivity unique.
Because of its strong and active nature, it is widely used in the field of synthetic chemistry. It can be used as a raw material to make fine chemicals such as medicines and pesticides. However, because of its strong activity, when operating, one must be cautious, like walking on thin ice in the abyss, to prevent its sudden changes and cause disasters in an instant.

2-% hydroxyl-3-methyl-5-nitropyridine, the physical properties are:
Its shape is mostly crystalline powder, the color is white or nearly white, and it is stable at room temperature and pressure. In case of hot topic, open flame or strong oxidant, there is a risk of explosion. The melting point is about a specific value, which is an important indicator when identifying its purity. Its solubility, in organic solvents, such as ethanol and acetone, has a certain solubility, but slightly soluble in water.
On chemical activity, because its structure contains nitro, hydroxyl and methyl groups, nitro has strong electron-absorbing properties, causing the electron cloud density of the pyridine ring to drop, making the electrophilic substitution reaction on the ring difficult and nucleophilic substitution reaction easy. Hydroxyl groups can participate in esterification and ether formation reactions, while methyl groups affect the molecular space structure and electron cloud distribution, and also play a role in reactivity.
In the field of organic synthesis, it is a key intermediate. Nitro can be converted to amino groups through reduction reaction to obtain aminopyridine-containing derivatives. This derivative is widely used in the creation of medicine and pesticides, such as the preparation of antibacterial, antiviral drugs, or pesticides with specific biological activities. It can also use hydroxyl reactions to introduce various functional groups and expand the structure types of compounds to meet the needs of different fields.

There are currently 2-hydroxy- 3-methyl-5-bromopyridine, and I would like to know its price range in the market. This product has a wide range of uses in the field of medicine and chemical industry. It is either a key intermediate for the synthesis of specific drugs, or an important role in the preparation of fine chemical products.
Looking at its price, it is actually affected by many factors. First, the cost of raw materials is important. If the starting material required for the synthesis of this 2-hydroxy- 3-methyl-5-bromopyridine is scarce, difficult to purchase, and the price must be high, which will then push up the price of the finished product. Second, the preparation process is complicated and simple, which also has an impact. If it needs to go through a multi-step reaction, and the reaction conditions of each step are harsh, the equipment and technical requirements are very high, so the production cost will increase greatly, and the price will also rise. Furthermore, the market supply and demand situation is crucial. If there are many people who want it, but there are few products, the supply is in short supply, and the price will rise; on the contrary, if the market is saturated, the supply will exceed the demand, and the price may decline.
In general, in the chemical raw material market, if this 2-hydroxy- 3-methyl-5-bromopyridine is of industrial quality, the purity is slightly lower, and the price per kilogram may be in the hundreds of yuan. If it is of high purity and reaches the medical grade standard, it is more difficult to prepare due to the strict control of impurities, and the price per kilogram may exceed 1,000 yuan, or even higher, up to several thousand yuan. However, this is only a rough guess, and the actual price depends on the current market conditions. Inquire with various suppliers to get an accurate number.