Hi. Is the reaction between primary amine and Si-OH possible or not?

I am using this procedure for my experiment since they used the same solvent and catalyst (fluoro-benzoyl chloride and pyridine), but I do not know if I am doing these steps right, can someone elaborate for me?

1. Does quench mean that I can drop ice-H2O in the mixture?

2. Does evaporating the solvent (pyridine) mean I can use the rotovap to get rid of it and then pour toulene into the mixture and use the rotovap again?

3. How can you tell how much mL (EtOAc and H2O) do I use for the partition (separatory funnel?

4. Can I wash the organic phase with sodium carbonate and water? Instead of sodium bicarbonate.

What parameters play a role in the ability of amines to be protonated in water? Can the base strength of amines be a sufficient measure to compare the protonation ability of two amines? For example, is the protonation ability of n-butylamine more than morpholine?

Thank you

Folks involved in the synthesis of organic compounds or anyone with organic lab setup expertise:

Would you recommend buying a chiller over a submersible water pump (a cheaper option-can buy a few for the same price for rotovap and distillation setup)

Thank you.

Hello, folks

I am looking for a way to link an aldehyde group (CHO) of a compound with an amine group (NH2) of an amino acid to form an imine (Shiff-base)-containing product. Unfortunately, I could not make it though I tried it by changing many parameters such as pH (2~9), temperature (25~80 C), solvents (DMSO~ethanol), reaction time (3~24 h), and so on...

I have also followed some recipes in the references regarding the reaction, but it was not so successful at this time.

Are there any one who is experienced in this experiment and what kind of solution would it be possible? Your kind advise would be pretty much appreciated !

Best Regards,

JH.

Hello dear colleagues, right now i'm a research fellow at the Environmental research center in Annaba-Algeria, and I'm lookin for any type of collaboration in the field of organic or medicinal chemistry. Please if there is any possibility contact me. I'll be very happy to work with you.

Hi,

I am setting up an esterification reaction using EDC/DMAP for R-OH and R'-COOH conjugation in water. However, one of my reactants R' also has an amine (-NH2) group. I am curious as to how the reaction would proceed with EDC and DMAP? And the conjugation would be between R-OH and R'-COOH, and not between R'-COOH and R'-NH2.

Thanks in advance,

Aazam

I'm looking forward to modify this molecule for the sake of enhacing the biological activities.

Could you suggest me any proposition?

Dear Researchgate Community,

I am currently trying to couple taurine to a protein via EDC reaction. I have already tried the following attempts:

1) Direct coupling at either pH 5 - 6, by only using EDC

2) Direct coupling in a two-step reaction with the aid of NHS

3) Succinylation of the lysine residues of the protein, then coupling by EDC only at pH 6

For all attempts, I have used around 7-fold molar excess of EDC to expected -COOH groups of the protein, and around 9-fold molar excess of taurine, if not even up to 20-fold.

The way I analyze "coupling efficiency" is by measuring the zeta potential of the dialyzed product at different pH, in hopes that since taurine "masks" lysine residues and offers a sulfonic acid instead, the IEP must drift to more acidic pH values. After succinylation alone, such a drift could be observed, but after EDC reaction, I keep finding an IEP that is been even more basic than my native protein, which could be caused by side-reactions due to EDC. After EDC/NHS reaction, the IEP is unchanged compared to the native protein.

I have found a paper (doi: 10.1007/bf01046841) in which taurine was succesfully coupled to succinylated ovalbumin and couldn't find anything that I did differently in terms of pH and amounts of reagents. My only "weak points" would be the total volume I'm working with. Judging by this, I have always used more concentrated solutions of protein, taurine and EDC (by using less water). I wouldn't expect this to impact the reaction, but I might be very mistaken. Does anyone have experience or knowledge about this?

I would be very much thankful for any help. Could it really be the reaction volumes? Am I using too much EDC, facilitating the reaction to N-acyl-urea derivates (although I have found similar amounts of EDC in literature, and have used the same amount to successfully couple ethylenediamine to the same protein before)? Am I overlooking something vital?

Thank you in advance.

Hi, I want to esterify triglycine, the methodology I'm trying to follow indicates the use of thionyl chloride reagent. The thing is this is not sold in my country so I'm looking for a substitute. I would appreciate your recommendations