[tusk]

Hello, I need specific advice on how people find procedures for reactions. I learned a whole lot of reactions in organic chemistry, and there is a whole bunch of mechanisms and other peripheral information written down in my organic chemistry textbook (Wade), but no specific procedures. Nothing they have you study in organic chemistry class tells you how to find the procedure used to perform one of the reactions you were asked to memorize. For instance, I want to do something just really basic (no pun intended). Condensation reaction of an Aldehyde and Ammonia to an imine. I know it's an established reaction, I know it works, I know it's been done a million times. But I have no procedure for HOW to do it. Obviously I am not going to just mix chemicals and heat them willy nilly. I want to have some procedure look at. So I tried the reaction search feature at SciFinder Scholar. All it comes up with are "This is too general" and when I make it specific enough for the program to handle, I get a whole bunch of complicated articles where the structures are apparently so complicated that half of the images are not even showing up. Ive tried restricting the results to before 1970 (I imagine the reaction was discovered a long time ago). Nothing. Ive tried mapping atoms and establishing specific R groups. Nothing. When you want to perform an easy, basic, established reaction, what resource do you use in order to get a procedure for that reaction? It is not enough for me to know that reactions exist and why they happen. I want to know the methods people generally use to perform those reactions. And I want to do that not just for this particular condensation reaction, but for any reaction I come across in my organic chemistry textbook. Once I get practice searching for the really fundamental reactions, then I will feel more confident in using the various tools (be it SciFinder or something else) to look at more complicated reactions and to apply the knowledge generally. *delete me*

[Babcock_Hall]

In olden times one could consult book series, such as Organic Synthesis or Biochemical Preparations.  In addition I have found the book "Reactions and Syntheses in the Organic Chemistry Laboratory" by Tietze and Eicher to be quite useful for simple compounds.  Nowadays I usually use SciFinder to find the synthesis of a particular compound.

[tusk]

Thank you for your reply and those references. Im going to get them. I think they will be helpful!

[rolnor]

If you tell us what aldehyde and what amine you want to condense whe can suggest conditions.
Generally you mix them slowly in presence of a dehydrating agent like molecular sieves.
https://en.wikipedia.org/wiki/Imine

[tusk]

Thank you Rolnor. Most of the aldehydes will be benzaldehydes or aldehydes from other aromatic ring systems, both decorated and undecorated with various substituents like halogens and methyl groups. However, I am most interested in the process of finding out how to answer this question. I want to be able to come up with the procedure for a reaction when I have an idea of what I want to perform. If a substrate needs a nitro group, for example, I want to know how to perform a reaction to nitrate it. Too often my chemistry textbooks just tell you that a reaction exists and why it happens, not exactly how to perform it and safety precautions, etc. I want to have the ability to go a figure out how to perform a reaction I want to do. SciFinder scholar seems to work sometimes. But other times it just gives me trouble. Granted, I am a relatively new user of it. But it seems like there must be a resource where less seasoned chemists can turn to when they want to perform something basic. I'd like to be able to show some initiative in my lab and be able to find procedures to reactions and perform them to improve my synthesis skills. If I have a paper that explains a detailed procedure for how to conduct reactions on an alcohol or amine substituent, but I am not starting with such a substituent, I want to be able to go put those substituents on the substrate so that I can later do what is in the paper. If everyone just uses SciFinder scholar, then I guess I am going to have to just become more skilled with it. But what would you do in my situation? Thanks!

[rolnor]

Aromatic aldehydes are very good substrates for this reaction. Just have a 5% solution av aldehyde in CH2Cl2 with some magnesium sulphate and ad the amine. Its not even nessecary with magnesium sulphate really.
The imine is a bit acid-sensitive so if you purify with silica chromatography you can ad a little triethylamine when you pack the column.
You can look in Marchś advanced organic chemistry to find a reference in Organic Synthesis, its generally very good synthesis description in these.
Generally its better to buy startingmaterial rather then making them by nitration etc. but if you want to learn more Marchś book is a good startingpoint.
If you have Scifinder its a powerfull too, its worth learning, you save time, money and effort.

https://www.amazon.com/Marchs-Advanced-Organic-Chemistry-Mechanisms/dp/1119371805

[Babcock_Hall]

I work with aromatic aldehydes, and I have found SciFinder is extremely valuable in finding protocols.  I doubt that I am tapping its fully potential.

[tusk]

Thank you Rolnor and Babckock_Hall. Rolnor, thank you for that simple procedure for making an imine with an aromatic aldehyde and an amine. I will look up Marchs advanced organic chemistry with the link you gave. It's very valuable for me to learn about references such as these. Noted about buying starting material (actually my PI said that to me too the other day). Babock-Hall, thank you about reinforcing value of SciFinder. I think I just need to get a little better at it. More training videos and a lot more practice

[Babcock_Hall]

Offhand the only thing I can think to say regarding tips is that there are three levels of searching: exact, substructure, and similarity.  All three options can come in handy.