hi
i'm going to do a reaction between Carboxylic acids and amine.
is there any body who can introduce some papers or something to find out that we need how much of each component ?? and what is needed condition ??such as Temperature, solvent , and condition for removing solvent , catalist like DCC ...
There are several very good reviews on amide formation:
C Montalbetti and V Falque, Tetrahedron, 2005, 10827-10852
E Valeur and M Bradley, Chem Soc Rev, 2009, 606-631
When you use the cabodiimide reagents (DCC, DIC, EDC), you can add catalysts such as DMAP or HOBt. The reactions can be done in DCM, THF, DMF. You might want to be careful of racemisation though.
You can activate your acid to acyl chloride with oxalyl chloride and catalytic DMF.
Other excellent reagents such as the phosphonium salts (BOP, PyBOP, PyAOP...) need DIEA or TEA.
finally, the uronium salts (HATU, TBTU, HBTU...) are also very effective.
the phosphonium and the uronium salts can be a bit expensive, the carbodiimides (DCC in particular) can be a bit difficult to purify and may lead to partial racemisation of amino acids. I like to use the acyl chlorides but the conditions can be a bit harsh.
I hope this helps
Solvents must be dry! You either should buy fresh anhydrous solvents for this reaction or should dry them yourself following a known procedure for drying.
If you use a tertiary amine as an auxiliary base in this reaction I would recommend drying that too.
numerous method exists pl check protective group in organic synthesis by theodora green
You can use T3P solution:
https://www.organic-chemistry.org/abstracts/lit3/412.shtm
One of the best solutions include EDC/NHS zero length activator/coupling agent. The media could be aqueous and temperature recommend between 2-6 C degrees. Noticeable; Amine I (NH2) could activate through this pathway.
Greg Petruncio ok, can you help me to dry procedure ?!
I mean how to dry it ?
when i wanted to remove my solvent that was DMF, I put my material in vacuum oven to exit its solvent
it depends on the solvent. you can purchase a small bottle of the dry solvent you want to use and give it a try
One of my best procedure to synthesize amide by reacting carboxylic acid with amine is the following:
Carboxylic acid ( 1 equiv.), amine (1 equiv.), EDC HCl (1 equiv.) and HOBt (catalyst). Solubilize Carboxylic acid in DMF at 0 °C and add EDC and HOBt. Let stir in the same conditions for 15 min, then add the amine and let the mixture to stir at room temperature overnight. In my experience, dry solvents are better, but also normal DMF works well; the yield in this case is just reduced by a 10-15%.
In addition with these reactives also the purification will be quite easier. After the reaction is finished, just dilute the mixture with ethylacetate and wash the organic phase with Na2CO3 saturated solution (to remove unreacted cooh and HOBt), then with NH4Cl saturated solution (to remove the unreacted amine and EDCU) and finally with brine (to remove DMF). Dry the ethylacetate phase over anhydrous Na2SO4 and concentrate. Usually the crude obtained contains your amide almost pure and it will be easier to purify by crystallization or chromatography. Of course, it will depend in addition by the chemical characteristics of your subtrates and product.
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