thiophene, 2-(trifluoromethyl)-

What you said about "2- (Sanxiang methyl) -" is a strange expression. In the classics and common sense that I know, such combinations are rarely seen. However, if it is strong to solve it, it is necessary to clarify what "Sanxiang methyl" refers to.
In many ancient books such as the number of tricks, alchemy, and medicinal herbs, obscure words are often used to refer to things. " The regional title of "Sanxiang" already existed in ancient times, but the word "methyl" did not have this chemical concept in ancient times. If it is speculated from the ancient meaning, or it is based on the first and first meaning of "A", or it is related to the armor of "armor", "Sanxiang methyl" may be produced in the land of Sanxiang and involves something with special meaning, and is connected with "2 -", or is related to a certain measurement, orientation, and step.
Its main use, if this is the record of the recipe, or the step identification of the preparation of medicinal pills and the production of utensils, "2 -" or the initial state of a certain stage, subtract "Sanxiang methyl", or to remove or add specific things, in order to achieve the effect desired by the recipe, such as refining longevity medicinal pills need to remove impurities and add special medicinal introductions. If it is geographical or related to the public, or a method for marking the orientation and topography, "2 -" or a certain orientation identification, subtract the land objects involved in "Sanxiang methyl" to clarify the good and bad luck and the veins.
However, this is all speculation, because the information given is too brief and peculiar, it is difficult to accurately analyze. To understand its true meaning, more context and background information are required.

"Tiangong Kaiwu" was written by Song Yingxing in the Ming Dynasty, aiming to explain all kinds of process technology and production experience. However, the chemical expression "2- (triethylmethyl) -" mentioned by you is not something that can be involved in the era of "Tiangong Kaiwu". This is a modern chemical term. However, if only the related physics of "triethylmethyl" is discussed, it can be stated as follows:
"triethylmethyl" Such groups, if they form substances, have quite unique physical properties. In terms of morphology, they may be in a liquid state. Due to their hydrocarbon structure, the intermolecular force is not strong, and it is difficult to be solid at room temperature. Looking at its color, or colorless and transparent, many organic compounds containing such hydrocarbon groups are more so, because there is no chromophore in its structure. Its odor, or has a special hydrocarbon smell, is slightly fragrant but also slightly irritating, due to the characteristics of alkyl groups.
When it comes to volatility, because of its relatively weak intermolecular force, the volatility should not be weak, and it is easy to diffuse in air. In terms of solubility, because it is an organic group, it is lipophilic and easily soluble in many organic solvents, such as ethanol, ether, etc., but it is difficult to dissolve in water. Because water is a polar solvent, it contradicts the structure of non-polar "triethylmethyl" substances. < Br >
Its density is smaller than that of water, and there are many hydrocarbons. The relative mass distribution of the groups composed of carbon and hydrogen atoms in the molecular structure makes the overall density inferior to that of water. And these substances are mostly flammable. Due to the presence of carbon and hydrogen elements, they can burn violently in sufficient oxygen to generate carbon dioxide and water.

The chemical substances involved in "2 - (trichloromethyl) -" are quite complex in nature. This group is introduced into the molecule and often changes the properties of the substance.
In terms of physical properties, those containing this structure have a melting and boiling point that may be unusual. Due to the large mass and steric resistance of trichloromethyl, the intermolecular force changes, and the melting and boiling point may rise or fall. And its solubility also changes. Trichloromethyl has a certain polarity, and its solubility in polar solvents is better than that without this group.
In terms of chemical properties, the chlorine atoms in trichloromethyl have strong electronegativity, which makes the carbon atoms partially positively charged and easy to become targets for nucleophilic reactions. When encountering nucleophilic reagents, such as alcohols and amines, a substitution reaction may occur. The lone pair of electrons of the nucleophilic reagent attacks the positively charged carbon, and the chlorine atom leaves to form a new compound.
At the same time, this structure also has characteristics in redox reactions. When the carbon of trichloromethyl is in a higher oxidation state, it may be reduced by a strong reducing agent, and the chlorine atom is gradually replaced by hydrogen. When encountering oxidizing agents, it is difficult to be oxidized because of its stable structure, but under certain strong oxidation conditions, the carbon-chlorine bond may break, and then oxidation products containing carbonyl groups are formed.
Furthermore, this chemical structure is widely used in the field of organic synthesis. With its unique reactivity, it can build a variety of complex organic molecular structures, providing key intermediates for new drug development, materials science, and many other fields, and promoting the progress and innovation of science and technology.

What is the preparation method of dijia- (Sanchuan methyl) -? This question is related to the addition of specific ingredients in the sugar production process.
The ancient preparation of jelly is quite exquisite. First take high-quality millet or glutinous rice, soak it in water, and make it moisturized. Then drain it and steam it in a retort, so that the rice is cooked and transparent, without sandwiching.
As for "dijia- (Sanchuan methyl) -", it may be a unique additive at that time. Or this is an herb with a unique aroma that can increase the flavor of the taste; or it is a special mineral that can help the condensation of the jelly and make its texture better.
When the rice is steamed, let it cool to a suitable temperature, crush the malt and mix it with the cooked rice. The ratio should be accurate. The malt contains amylase, which can saccharify the starch in the rice. After mixing the two well, put it in a warm place, cover it with a quilt, and let it ferment. During this period, it needs to be checked frequently, and it should not be overheated or too cold.
After a certain period of time, when the saccharification is completed, filter it with a cloth, remove the residue, and leave the juice. Put the juice into a kettle and boil it slowly over low heat. When boiling, stir it frequently to prevent it from being burnt. When the juice is thickened, it should be regarded as amber in color, sticky and can be brushed.
And the addition of "Sanchuan Methyl", either at the beginning of fermentation, uses its properties to promote saccharification; or in the middle of cooking, to increase the color and taste of the taste. Although I don't know what "Sanchuan Methyl" is today, the craftsmen of ancient times have to go through countless attempts to obtain this exquisite formula and pass on this unique skill to future generations.

I look at what you are asking, but I am inquiring about "2 - (Sanxiang methyl) -" in the market price range. Sadly, the name "Sanxiang methyl" has never been heard of in the classics and ordinary things in the world that I know. Either it is a very rare substance, or it is a new and uncommon word.
If it is an ordinary commercial transaction, the market price is often affected by many factors. The abundance of its raw materials is related to the level of cost. If the raw materials are easily available and sufficient, the price may be stable and low; if the raw materials are scarce and difficult to find, the price will be high.
Furthermore, the process of making this thing is also the key. The craftsmanship is simple, it consumes less manpower and material resources, and the price can be close to the people; the craftsmanship is complicated, and exquisite craftsmanship and precious utensils are required, so the price must be high.
And the situation of market supply and demand can also make the price go up and down. Those who ask for it are numerous, and those who supply it are few, the price will go up; those who ask for it are few, and the supply exceeds the demand, and the price will go down.
However, it is uncommon in the name of "Sanxiang Methyl", and it is difficult to know for sure what its price range is in the market. If you want to know its price, you need to investigate the origin, use, and origin of this object in detail, and visit all the parties who know this object, or you can get a clue.