Sciencemadness Discussion Board

Aniline Reactions

thebean - 2-1-2014 at 15:40

I picked up some aniline thinking maybe I'd use it to make phenol via the Sandmeyer reaction. I then thought about how I could make phenol with more convenient methods (thermal decarboxylation of salicylic acid). So I now am sitting with aniline on hand and nothing to do with it. Anyone have any ideas on interesting reactions? I don't have the most advanced glassware selection but I have access to a fair amount of reagents.

plante1999 - 2-1-2014 at 15:44

Make dyes, or medicines. Aniline is a starting point for many chemical reactions, especially the two I mentioned. Use it as a base in organic reaction, to make phosphines or phosphate ester for example.

HeYBrO - 2-1-2014 at 16:34

There are plenty of reactions using aniline here from the SM library. from page 153 onwards most use aniline. Be careful, as this is an older book so some of the safety considerations are not the same as today.

ParadoxChem126 - 2-1-2014 at 17:45

Prepare phenyldiazonium chloride from the aniline. First, react the aniline with hydrochloric acid. Then, slowly add sodium nitrite solution to the resulting aniline hydrochloride. Be sure to use the diazonium salt immediately as it decomposes very quickly upon storage.

Phenyldiazonium chloride can be used in the Sandmeyer reaction to prepare a variety of monosubstituted benzene compounds (e.g. chlorobenzene, bromobenzene, benzonitrile, etc.). Benzene itself can be prepared from the diazonium salt by reduction with sodium stannite. As plante said, phenyldiazonium chloride can be used in azo coupling reactions to form dyes and medicines. For example, the diazonium salt can be reacted with phenol dissolved in aqueous sodium hydroxide solution to yield p-hydroxyazobenzene, which dissolves in organic solvents to give an impressive orange color. Vogel's Textbook of Practical Organic Chemistry describes several diazonium salt reactions. You can find this book in the Sciencemadness library.

Here is a picture of a dilute solution of p-hydroxyazobenzene in acetone.

Synthesis of p-hydroxyazobenzene.png - 3kB p-hydroxyazobenzene.jpg - 135kB

[Edited on 1-3-2014 by ParadoxChem126]

[Edited on 1-3-2014 by ParadoxChem126]

thebean - 2-1-2014 at 21:49

Quote: Originally posted by HeYBrO  
There are plenty of reactions using aniline here from the SM library. from page 153 onwards most use aniline. Be careful, as this is an older book so some of the safety considerations are not the same as today.


Thanks, I'm looking forward to doing a lot of this!

eidolonicaurum - 3-1-2014 at 01:26

I think you can make HNB from aniline, try this thread: http://www.sciencemadness.org/talk/viewthread.php?tid=259
Providing you're mad enough, of course! :D