I Have a Research Support System

In the chemical laboratory, time passes very quickly, because there is almost no time to stop, and there is no time to think about the concept of "time". When you are busy, you are really like a "top".

Especially for players like Xu Qiu, who like to deal with multiple reactions at the same time, there is no need to worry that they have nothing to do. In the gap between this reaction, you have to go and see if the other reaction is normal, and then return to continue processing. I have to check again, even if I have time occasionally, I have to deal with the experimental garbage and dirty glass instruments generated by the reaction.

Back at the A501 office, Xu Qiu washed his hands carefully in the sink. Potassium fluoride was used after all, so he had to be a little more cautious. In case some dust got on his hands and he licked them at leisure, he would be tricked .

While washing his hands, Xu Qiu looked at himself in the mirror. Due to wearing a gas mask for a long time, the straps formed a diamond-like mark on his face. He rubbed his face vigorously, and the mark gradually disappeared.

At this time, Xu Qiu heard the notification tone of the mobile phone. He shook his hands, wiped off the remaining water with toilet paper, turned on the mobile phone, and saw many messages from the school girl:

"Brother~"

"Where are people?"

"[Sudden Appearance.jpg]"

"I'm so sleepy, I'm going to take a shower first."

"I'm back, is senior still busy?"

"I can't hold it anymore, I'm going to sleep."

"Send me a message when you're done with the experiment."

Xu Qiu smiled. In the midst of busy experiments, it feels good to have someone who cares about him.

He thought for a while and replied:

"I just finished the experiment, everything is fine, junior girl, go to bed first, good night."

"Then I'll sleep, brother, good night~"

"The other party is typing..."

After waiting for a long time, but no news came, Xu Qiu chuckled, guessing that the junior was planning to send a message, but she fell asleep.

After putting down the phone, Xu Qiu washed up, locked the door, turned off the lights, and began to rest.

...

On Thursday morning, Chen Wanqing was still supplementing the experimental characterization data of her IDT-T(EH)-ICIN system, and she had no time to do the synthesis for the time being.

Wu Shengnan and Han Jiaying took the school bus to Zhangjiang together.

Together with Xu Qiu, the three of them chatted for a while in room A501, making preparations before the experiment, and entered the laboratory.

The school girl is going to post-process H21 and H22 today. The experimental task is relatively easy. It only needs to remove part of the chloroform solvent by rotary evaporation, then use methanol anti-solvent to precipitate the polymer product, and finally dry it.

The experimental tasks of Xu Qiu and Wu Shengnan are relatively heavy. They have a total of five reactions to deal with, and they are all relatively complicated reactions. The synthesis of two D units requires the low-temperature reaction of n-butyllithium. The synthesis of a unit A requires malononitrile to introduce cyano groups. In addition, when purifying small molecules, it is unavoidable to involve columns.

After yesterday's investigation, Xu Qiu judged that Wu Shengnan's experimental operation level is good, and the two responses she voted for were relatively smooth, so today Xu Qiu directly gave the references to Wu Shengnan, and stopped teaching her to do the experiment. Postdoctoral fellow.

Start experimenting.

First of all, the third overnight reaction of ICIN-2Cl/F has been completed, and post-reaction treatment is required, which involves the use of ice-water mixture.

When Xu Qiu was doing "Organic Chemistry Experiments", the school's aging building had a special ice-making room, and ice buckets could be used to hold ice cubes directly. Now Zhang Jiang's laboratory does not have that condition, so he can only prepare ice by himself. The water is gone, that is, buy the cheapest ice dew mineral water directly, and freeze it in the refrigerator for later use.

Xu Qiu opened the freezer of the double-door refrigerator in the laboratory. There were more than 20 bottles of frozen ice water in it. They were all prepared a long time ago. Now they have turned into old ice, which feels cool to the touch...

Take out two bottles of frozen solid ice water, then cut them along the axis with scissors, put them in a plastic basin, and smash them with a metal chisel.

Although it sounds a bit wasteful, the price of a bottle of water is only one yuan, and any gram of materials in the laboratory costs several yuan, tens of yuan, and some materials even tens of thousands. The cost of this mineral water is negligible .

Xu Qiu prepared about 50 ml of ice-water mixture, added 20 ml of concentrated hydrochloric acid, then slowly poured the reactant solution into it, and then raised the temperature to 70 degrees Celsius for one hour.

Xu Qiu judged that the reaction was over. The ice water and concentrated hydrochloric acid were most likely used to treat acetic anhydride and triethylamine respectively, and let the product precipitate by the way.

Afterwards, after filtering and drying, two kinds of solid products IN-2F and IN-2Cl were obtained, the yields were 69% and 74% respectively, and the yield was about 6 grams.

Wu Shengnan also successfully synthesized IN-DM, because she did not split the reaction in half, so she got more products, reaching more than 10 grams.

During the process of processing at 70 degrees Celsius, Xu Qiu and Wu Shengnan also processed the product of the first step of the synthesis reaction of unit D at the same time.

The product was first extracted with dichloromethane, then washed with water, dried over anhydrous magnesium sulfate, and finally the solvent was removed by rotary evaporation to obtain a crude product, which stopped at the step before passing through the column.

This synthesis reaction is a Stille reaction, which is not difficult in itself, but the post-processing of the reaction needs to pass through the column, which is more troublesome.

Moreover, the reaction uses TT units substituted by monotrimethyltin, and the tin reagent is relatively expensive. Although the structure of TT is relatively simple, it costs several hundred per gram. After throwing about 1 gram, the yield of the crude product that has not passed through the column is about 85%, which is not bad.

Generally, as long as you can get about 200 mg of the product, it is enough to publish an article. If you use it sparingly, 100 mg is even enough.

This is mainly due to the "spraying method" developed by Xu Qiu. This method greatly reduces the amount of solution required for coating. To prepare 1 ml of solution, consume about 10 mg of material, and theoretically 50 tablets can be coated. device.

The experiment in the morning ended smoothly without any accidents.

The three people put the processed product into a vacuum oven to dry, or put it into a special reagent tank, and store it in a nitrogen atmosphere away from light.

In the afternoon, Han Jiaying had successfully obtained the H21 and H22 products. Xu Qiu copied them into the simulation laboratory and arranged for device performance testing.

The school girl had no experiments to do, so she was arranged to go out to run errands to drink liquid nitrogen.

It is worth mentioning that because Chen Wanqing often used liquid nitrogen before, he felt that the eight-pound bottle was inconvenient and unsafe, so he used a ten-liter liquid nitrogen container.

The liquid nitrogen container is like a small gas tank with a hollow interior, a thermal insulation layer, a cover on the top, and two spoon-like things that can scoop out the liquid nitrogen in the container.

With the liquid nitrogen container, you can use the cart to take the liquid nitrogen. Unless the cart is overturned, there is generally no risk of liquid nitrogen being dumped out, and the liquid nitrogen inside can also be stored for a longer period of time. As for missing it all.

Xu Qiu continued the final step of the synthesis reaction of ICIN-2Cl/F, that is, the reaction of IN-2Cl/F with malononitrile under the conditions of sodium acetate and ethanol.

The process of this reaction is not difficult, but the toxicity of malononitrile is relatively severe.

Xu Qiu has inquired that malononitrile is highly toxic, and the toxicity is similar to cyanide. The specific role of cyanide is to inhibit cellular respiration and cause tissue hypoxia. Rats were subcutaneously injected with a near-lethal dose of this product, and dyspnea, cyanosis and convulsions occurred, and the excretion of thiocyanate in urine increased.

"This is the key reaction to introduce the cyano group, and it cannot be circumvented. Senior sister has done a similar reaction before, and she is still alive, so don't worry."

After comforting himself, Xu Qiu arranged for himself and Wu Shengnan to wear gas masks, polyethylene protective clothing, and three-layer gloves. Take out the reagent bottle of malononitrile in the reagent cabinet.

Theoretically, this kind of high-risk experimental drug must be "double-locked", that is, two designated security officers are arranged, and two locks are arranged. Only two security officers can be used at the same time, but now the school is not strict. In other words, no one checked at all, so such a system was not implemented in the laboratory...

The starting point of many rules and regulations is good, but it is very difficult to implement them.

For example, Wu Feifei and Chen Wanqing are two security officers (Xu Qiu and Han Jiaying are undergraduates, and strictly speaking they cannot be regarded as Teacher Wei’s students, so they cannot be security officers, and Wu Shengnan hasn’t come here before, so it doesn’t count). Wu Feifei had to come here for the dangerous experiment. The commuting time on the road was more than two hours, and she tossed about two or three times a week. Wu Feifei didn't want to do the experiment.

You must know that malononitrile is not the only high-risk drug. In theory, fluoride and tin reagents in the laboratory are also highly toxic. One of these three is suffocating, one makes bones hurt, and the other can cause hair loss...

It is now June, and the outdoor temperature in Shanghai is not low, but the indoor temperature is maintained at about 20 degrees Celsius under the action of the air conditioner, so malononitrile, which has a melting point of 32-34 degrees Celsius, is still in the state of white crystals.

Xu Qiu carefully weighed 2 times the equivalent of malononitrile, dissolved it with IN-2Cl/F with absolute ethanol, and then added anhydrous sodium acetate.

The expected reaction conditions are stirring at room temperature for 1 hour, and then reacting in an oil bath at 60 degrees Celsius for 3 hours.

After completing the experiment, Xu Qiu felt his body's functions. Apart from feeling a burst of rapid heartbeat, there was no other abnormality. It should be that he was not poisoned.

Fortunately, this kind of cyano group experiment does not need to be done many times, and it can be used for a long time after one synthesis, otherwise it is really too much.

PS: Qidian modified the monthly ticket rules in January. You can get more than 200 monthly tickets as long as you update steadily every month, and the pressure of adding more is a lot more... In addition, there are monthly tickets that exceed 1000, and the bonus can be shared in the next month. So let's set a small goal this month, 1000 monthly tickets, I don't know if it can be achieved, the high probability is a little hanging...

PS2: Now is the double monthly ticket period, one vote is worth two votes, and re-voting after the expiration date is only counted as one vote, please ask for a wave of guaranteed monthly tickets.

PS3: There is no way to update during the New Year's Day. After the holiday, the number of words owed will be paid off together. Currently, there are about five or six thousand words owed.

PS4: The plot of the synthesis experiment may be rather boring, but it’s not good to write it in one stroke. You can’t say “Xu Qiu waved his hand, and the materials will be synthesized.” I’ll try to make it interesting. In fact, if it is a repeated experiment, I seldom mention it, and I only mention it briefly. Most of the experiments written in detail now are new experiments.