Increasing the Yield
If given the opportunity, Shen Qi to join Scientific Expedition Team. He has four places he most wants to go: South Pole, the Arctic, the equator, and Mount Everest.
From an Earth Physics perspective, the polar regions and the equator are very special areas, and various natural data from these regions have far-reaching and far-reaching effects on the entire globe. Mount Everest is the highest peak in the world, and data collected there has extremely important scientific significance.
Going to these four locations and collecting the ideal data is Shen Qi's medium- to long-term plan, something he wants to do.
The purpose of this task was to verify one of Shen Qi's ultimate conjectures.
Shen Qi's physical training continues every day. Scientific expeditions are very physically demanding, and in special circumstances, one also needs to have good explosive power and agile physical reactions.
The CO1C project in the central Chemistry Laboratory has been underway for some time. Old Yan and Cheng Haonan optimized the experimental steps based on the route designed by Shen Qi and synthesized preliminary samples.
However, the overall yield of the sample was only 2%, which is clearly unacceptable.
Only when 2% is multiplied by at least 10 can it be considered a valuable scientific research result.
Shen Qi changed into a lab coat and entered the Chemistry Laboratory to work with Old Yan and Cheng Haonan on a project to improve CO1C yield.
"Project C01C, benzothiazide experiment, ninth time," Old Yan muttered to himself as he wrote in the experiment log.
The main operator was Cheng Haonan, who had excellent hands-on skills. He took 5g of benzothiazide and 12.5g of Potassium Carbonate as starting materials, dissolved them in 250ml of DMF, added the halogenated product while stirring, and stirred for 3 hours.
The mixing is carried out in a mixer, while TCL monitors the process.
TCL, or Thin Layer Chromatography, involves coating a suitable stationary phase onto a silica gel plate for drug identification, impurity testing, content determination, and tracking of reaction progress.
Shen Qi set the route, Old Yan and Cheng Haonan set the drug dosage, specific experimental methods, and operation/monitoring/testing details.
The synthesis of a target compound, from route design to sample production, is a comprehensive task that requires a team to complete.
Organic Synthesis Route Design tests a chemist's strategic vision and deep chemical knowledge, while the actual operation tests the lab technician's patience, meticulousness, and sense of responsibility.
There is a fundamental difference between a chemical lab technician and a chemist. A chemist may be short-tempered and careless, while a lab technician is cautious and meticulous in everything he does.
Ultimately, it is the chemists who will be remembered by the world; those who are cautious and meticulous their whole lives may only ever be able to work as operators.
It's not that patience, meticulousness, and a sense of responsibility are flaws; on the contrary, they are shining qualities of human nature.
A meticulous, patient, and responsible chemistry lab technician, with a little ambition and strategic vision, has the potential to become a chemist.
Of course, ambition and strategic vision require accumulation over time, as well as a bit of luck.
Old Yan had always worked at Yenching University, had a stable income regardless of circumstances. He wasn't particularly ambitious; his biggest wish was to smoke the finest cigarettes every day, without any limit.
Cheng Haonan's ambition was completely exhausted during his five-year career as an organic worker. Compared to the stark reality of life and survival, ambition seemed too distant.
It was Shen Qi who ignited the ambitions buried deep within Old Yan and Cheng Haonan. The C01B patent sold for over a million, which Shen Qi divided by three, and the three of them split it equally.
Material gifts are the most primal means of driving a person's ambition.
Although primitive, it is undeniably effective.
A higher level of motivation than material things is honor.
If one's desires for material possessions and honor are satisfied, then all that remains for a person is their ideals.
Before an ideal is realized, it often exists only as a conjecture.
The stirrer is working, and TCL is monitoring it in real time. This process will last for 3 hours.
At least one person must remain in the lab for at least three hours to monitor the experiment's progress and ensure lab safety.
Therefore, it's perfectly normal that researchers and lab technicians don't have time to go out, flirt, date, or socialize. Scientific research is extremely time-consuming and energy-intensive; diligence leads to mastery, while idleness leads to ruin.
Shen Qi spent three hours in the lab with Old Yan and Cheng Haonan, and they discussed how to improve the overall productivity.
At this point, TCL monitored that the raw material reaction was complete, and the next step was to let it stand at room temperature overnight.
The experimental drugs were stored overnight, and so were the lab technicians. Shen Qi and his two companions went home to spend the night with their respective women. Nothing more was said that night.
The next morning, the three of them arrived at the laboratory. This time, Shen Qi was in charge of the operation, and he also had to practice his practical skills from time to time.
Shen Qi added an equal volume of water to the intermediate product that had been left overnight, extracted it with Ethyl Acetate, combined the organic layers, washed it three times with saturated brine, dried it with anhydrous Sodium Sulfate, and separated it by Silica Gel Column Chromatography to obtain a slightly yellow crystalline compound 2.
"Director Shen's practical skills are very proficient," Cheng Haonan praised.
"I secretly practiced while you two weren't around, you know," Shen Qi said, picking up his previous experimental records and looking at them. "In the previous experiments, the yield of compound 2 was 78% to 82%, which is a very good result."
"The data were all very good up to compound 4, but the problem lies in step 4 to 5." Old Yan began the next step, stirring compound 2, Sodium Hydride, and DMF in a water bath under nitrogen protection.
It is clearly visible that the reaction solution changed from a slightly disgusting pale yellow to a vibrant rose red.
After adding DMC, the first step of extraction, washing, drying, and Silica Gel Column Chromatography was repeated to obtain oily compound 3 with a yield of 68%.
Steps 3 to 4 involve dissolving compound 3 in methanol, adding Hydrazine Hydrate, and letting it stand overnight.
The three men returned to their respective homes and spent the night with their respective women. Another night passed without incident.
The following morning, the three-person chemistry team at the center obtained compound 4 with a yield of 55%.
The two-day, two-night experiment has progressed to this point, and the data is very promising.
"From 4 to 5, the yield plummeted from 55% to 2%, which is a huge problem." Shen Qi has been reviewing the situation for the past two days and has come up with a new plan. "Let's change our approach and replace some of the hydrophobic side chains with hydrophobic aromatic heterocycles. Let's get started. Old Cheng will be the main operator, Old Yan will assist, and I'll just observe and remain silent."
"Is it really appropriate to replace some of the hydrophobic side chains with hydrophobic aromatic heterocycles?" Old Yan asked with some doubt, while Cheng Haonan had no objection at all.
In fact, Shen Qi admired Old Yan's skepticism even more. He said, "Isn't that what experiments are all about? You keep trying and doing. Only by doing it can you know which one is more suitable for you and which one is destined to be just a passerby in your life."
"Practice makes perfect." Old Yan chuckled and said nothing more.
Guided by the new approach, the trio dissolved carboxylic acid in acetonitrile, added HOBT and stirred for 15 minutes, then added EDCI and compound 4, and left it at room temperature overnight.
The organic experiments were conducted day and night. On the morning of the third night, the trio finally obtained the target product with a total yield of 25% through a series of purification operations.
After testing, it was found that the physicochemical constants and spectral data of the target product were all satisfactory.
The structure of the compound designated C01C is benzothiazinone + benzene ring + CH3(CH2)9CH2. What is interesting about this compound structure is the design of the long hydrophobic side chain.
Shen Qi and his team designed the target molecular structure and prepared the sample using a predetermined method.
"25%!"
"It's a success!"
"Another new compound has been born!"
The most fascinating aspect of chemistry is the creation of new substances. Shen Qi, Cheng Haonan, and Old Yan high-fived in celebration, clearly excited.