I Have a Research Support System

After dinner, Wu Shengnan's experiment had been completed. She was not in a hurry to return to Handan, and stayed in Zhangjiang to continue writing her two articles, a review that she planned to submit to AFM, and an experimental work that she planned to submit to ACSAMI.

Generally, friends who come to Zhangjiang like to catch the last bus to go back at night. On the one hand, the earlier school bus will be blocked due to the evening rush hour, which may take more than half an hour; Jiang won't be caught by Mr. Wei, and it doesn't matter to paddle occasionally.

Xu Qiu still has an experimental plan in the evening. He wants to submit two synthetic reactions, the third-step reaction of ICIN-2F and ICIN-2Cl. Today he has no plan to return to Handan. He plans to stay in Zhangjiang for another night. He thought about it carefully. It seems that Xu Qiu and senior sister Chen Wanqing slept together in Zhang Jiang's bed. This can be regarded as "sleeping together in the same bed" in the literal sense, but not at the same time.

Speaking of which, apart from Mr. Wei's research group in the whole building of Zhangjiang Micro-analysis Building, Wanyousheng's research group is relatively active, but there are no beds in Wanyousheng's laboratory, although some of their students have stayed in the Zhangjiang campus for a long time. , but they applied for a dormitory in the Zhangjiang campus, so they don't need to sleep in the laboratory building.

In other words, in most cases, there is only one living person in this building at night.

At night, in an unknown experimental building, the corridors exuding green light, the air is filled with an inexplicable smell, and there is only one living person around, resting here for a night, it is quite exciting to think about it.

While Xu Qiu was thinking wildly, he suddenly received a WeChat voice call request from his junior. Wu Shengnan heard the sound and looked in his direction.

Xu Qiu picked up the phone and pointed to the screen. Wu Shengnan nodded, expressing that he didn't mind, and he answered the call from the school girl with earphones on.

"Brother, did today's experiment go well?"

"Everything is normal at present. We have helped to deal with your two reactions H21 and H22, and now they are undergoing chloroform Soxhlet extraction."

"That's great~"

"By the way, didn't you want to try the PBDB-T system before, why didn't you do it later?"

"When I was buying monomer raw materials, Shencheng said it was temporarily out of stock, and asked me to contact them after a while."

"Okay, then don't forget to follow up, the school girl is looking for me... is it about the article?"

"Yeah, I've finished writing the reply document for review comments. Mr. Wei asked me to send it to you first."

"Send it here, don't hang up the phone, I'll help you change it online directly."

"Okay~"

Xu Qiu's computer was connected to the WeChat version, and he soon received the file from the school girl. He downloaded the file, clicked to start viewing it, and then revised it one by one while explaining to her:

"First of all, the ways of thanking should be diversified, so that the reviewers can feel our sincerity..."

"Since we have answered the fourth question of the first reviewer in such detail, we can completely modify this answer and put it in the main text. After all, the core role of the reviewer's opinion is to improve it. In our article, if the questions they raise can be implemented in the article, we should try to reflect it in the article..."

"The second reviewer's third question, their statement is wrong, you can argue (argument) with them, you don't need to follow the reviewer's meaning completely, well, here is a reference to a document, I will look for it... ...I found it, the DOI number is anie.201210944, I marked it directly in the WORD file..."

Xu Qiu made several suggestions in a row, and Han Jiaying kept responding with "um", "um".

When it comes to replying to review comments, Mr. Wei usually has stricter requirements and more urgent reminders, which he calls "the last battle before dawn".

Xu Qiu estimated that Mr. Wei would ask for it tonight, so he didn't chat with Han Jiaying much, and hung up the phone after sending the revised WORD file back to the school girl.

At around 9 o'clock in the evening, Wu Shengnan put on his schoolbag and boarded the school bus back to Handan, while Xu Qiu continued the experiment and dealt with the second step reaction of ICIN-2F unit synthesis.

The post-treatment of this fluorination reaction is relatively complicated, and the solvent needs to be distilled out, and the reaction product will be distilled out simultaneously with the solvent.

The reaction solvent is sulfolane, and its boiling point is as high as 285 degrees Celsius, so ordinary rotary evaporators cannot be used.

On the one hand, the temperature of the water bath in the rotary evaporator can only reach 100 degrees Celsius, and the temperature is too low, and the boiling point of sulfolane may not be reached even under reduced pressure; on the other hand, the vacuum pump used in the rotary evaporator has a poor vacuum effect , unable to provide high vacuum.

Therefore, it is necessary to manually set up the distillation device, use a mechanical pump to increase the high vacuum degree, and use an oil bath/electric heating mantle to provide a high temperature. At the same time, the temperature cannot be raised to a particularly high level. If it exceeds 220 degrees Celsius, sulfolane will quickly decompose. This produces black polymers and sulfur dioxide.

"The fluoridation reaction is troublesome." Xu Qiu sighed and started to work.

The distillation device is not difficult. He learned about the distilled water device when he was in junior high school chemistry. The device that Xu Qiu builds now is similar to the one at that time, but there is an extra decompression system.

Xu Qiu builds installations in the order of "bottom-up, left-to-right".

On the lower left is an oil bath, on which a distillation flask is fixed with iron clips;

The top of the distillation flask is connected with a glass tube with a branch nozzle, and a thermometer is inserted in the middle of the glass tube, and inserted directly into the liquid level of the distillation flask, but does not touch the wall of the bottle;

The branch pipe port is connected to the right with a condensation pipe, and the condensate pipe is connected with condensed water in the way of "bottom in and top out", and at the same time, it is connected obliquely downward to a horn pipe with a branch pipe port;

A small flask is connected below the horn tube as a liquid contact bottle, and the branch port of the horn tube is connected to a mechanical pump to provide a vacuum atmosphere.

After setting up, start the vacuum distillation experiment.

Turn on the condensate, and the liquid flow of tap water flows slowly in the condensate pipe.

Turn on the mechanical pump, the vacuum degree of the system decreases, and the boiling point of sulfolane decreases thereupon.

Set the temperature of the oil bath to the previous reaction temperature, which is 185 degrees Celsius. At this temperature, sulfolane will not decompose for a while.

The thermometer in the distillation flask detects the real-time temperature of the solution, which is rising steadily.

Afterwards, it is necessary to wait for the vapor of sulfolane to come out of the distillation flask engulfed by the reaction product, and become liquid at the condenser tube, and then enter the liquid contact bottle along the condenser tube and horn tube under the action of gravity.

Xu Qiu predicted that the entire distillation process would be relatively slow.

On the one hand, the amount of reactants in this step is relatively large, involving nearly 10 grams of reaction, so a total of 50 ml of sulfolane solvent was added before, and the distillation process usually comes out drop by drop, and a drop of water is 0.04- The volume of about 0.05 ml, other types of liquids, the volume level of each droplet is also around this value, and the second speed of distillation is about 1-2 drops per second;

On the other hand, the preheating process also takes a lot of time. It is impossible to rise to 185 degrees Celsius all at once, and it takes time for the temperature to be transmitted to the entire interior of the retort.

To put it in perspective, rounding is taking... a long time.

But Xu Qiu is not in a hurry, he has already planned to take advantage of this gap in distillation to start another reaction, which is the synthesis of ICIN-2Cl.

The first step reaction of ICIN-2F before is the reaction of reactant A and acetic anhydride to generate reactant B; the second step reaction is the reaction of reactant B and potassium fluoride to generate reactant C; the third step reaction , is the reaction of reactant B or reactant C under the conditions of acetic anhydride, triethylamine and tert-butyl acetoacetate to generate IN-2Cl or IN-2F respectively; finally, the fourth step reaction, IN-2Cl or IN- 2F reacts with malononitrile under the conditions of ethanol and sodium acetate to generate ICIN-2Cl or ICIN-2F.

What is being distilled now is the reactant C, and the reaction that Xu Qiu wants to start is to use the remaining half of the reactant B to carry out the third step reaction to obtain IN-2Cl.

Xu Qiu feels that the synthesis reactions he is now exposed to are becoming more and more complicated, but he is not interested in the specific reaction mechanism for the time being. Since there are existing literature reporting the synthesis of similar structures, and there are wheels made by others, just use them directly, etc. When the literature is not effective, then study it yourself.

After all, in this era of information explosion, knowledge is vast, and it is impossible to expect to master all knowledge with the power of ordinary people. It is already very rare to be able to achieve the ultimate in a small field.

Including the fluorination reaction using potassium fluoride, Xu Qiu is not sure what the use of the added polyethylene glycol monomethyl ether (mPEG) is, but this does not affect his use.

As for the triethylamine used in this reaction, he probably understood its function, which should be to provide an alkaline atmosphere.

After a little recall of the experimental procedures, Xu Qiu started the experiment.

First, use 30 ml of acetic anhydride and 15 ml of triethylamine to prepare a mixed solvent for the reaction, and connect a nitrogen balloon to provide a nitrogen protective atmosphere.

According to the MSDS, triethylamine is a colorless oily liquid that is irritating and toxic. If swallowed by mistake, it will cause poisoning and burn the skin. Its vapor will strongly irritate the eyelids and mucous membranes. It may cause combustion and explosion hazards when exposed to open flames, high temperatures, and strong oxidants. Has a strong ammonia odor.

"It's sour and smelly, why did I think of snail noodles..."

Xu Qiu complained, and then decisively used the gas mask, one acetic anhydride is enough to sour, now another one.

He is not interested in experiencing the "strong ammonia smell" for himself. He still remembers that during a high school chemistry experiment, a classmate overturned the ammonia water, and then the smell filled the entire room, and the students were evacuated urgently...

In comparison, microwave-baked durians and pressure cooker stewed *, this level of biological and chemical weapons are really too low.

Xu Qiu also didn't know why dangerous reagents such as ammonia water and concentrated sulfuric acid were used in high school chemistry experiments. He felt that random color changes, or reactions such as the formation of beautiful precipitates, would not be very good to attract students' interest. Well, why do you have to play with these dangerous things such as acid, alkali and alkali.

Moreover, some chemistry teachers are relatively vigorous in doing experiments, because in a certain special era, there was a gap in talent, and many old teachers in N-tier cities rushed to work without good training.

He heard that a teacher was conducting a teaching experiment in the classroom, and then turned over the alcohol lamp. The eyebrows of the students at the front table were all burned off, but fortunately they were not disfigured.

In fact, the problems of chemistry teachers are generally not big, after all, there are still a small number of problems.

The more serious problem is the English teachers. The pronunciation of many primary school English teachers is not standard, and the students they teach naturally have dialect accents, and some local elementary schools do not even have English courses.

There is no way to speed up subjects like language, and English is one of the subjects of the college entrance examination. Students from backward areas are born with a shortcoming in this area.

After preparing the mixed solvent of acetic anhydride and triethylamine, Xu Qiu added the remaining few grams of reactant B into it, leaving only 100 mg for characterization.

Next, Xu Qiu maintained the nitrogen atmosphere in the reaction bottle, injected tert-butyl acetoacetate through a rubber stopper into the reaction bottle of the two-necked flask with a disposable syringe, and then stirred overnight at room temperature.

At this time, the vacuum distillation device on the other side was also going about the same, the distillation flask had bottomed out, and there was almost no distillate on the horn tube.

It took a little less time than expected, less than an hour.

Xu Qiu added a small amount of water to the liquid-receiving bottle, white crystals precipitated out, and reactant C was obtained by filtration.

Judging from the shape of the product, the fluorination reaction should be a success. After all, the previous reactant B was pale red, and now the reactant C has turned into a white crystal.

The yield of this step is about 60%, which is acceptable, because he knows that there must be a lot of reactants left in the sulfolane solvent.

Xu Qiu quickly dried the reactant C in a vacuum oven, and then put the reactant C into the third step reaction in the same way as the reactant B.

After much tossing, by the time Xu Qiu cleaned up the mess in the laboratory, closed the laboratory and returned to the A501 office, it was already twelve o'clock in the morning.