Bubbleplate (Hive Bee)
09-19-04 20:42
No 532189
       Diethylamine - What Molar Amounts Required?     

In the original "N,N-Carbonyl diimidazole" process for making LSD, (see Post 395675 (Rhodium: "English translation (Yield of LSD freebase 57.5%)", Tryptamine Chemistry) ) almost equi-molar amounts of Lysergic Acid and Diethylamine were used:
"(5mmol) anhydrous D-Lysergic Acid... was mixed with… a solution of 0.40g (5.5mmol) Diethylamine in 5ml DMF”.
Yet, the same procedure listed in various new Patents (see Patent US6476199 and Patent US6063908 )specify a 10x molar ratio of Diethylamine to Lysergic Acid, quite a large difference!
Is there any good solid reason to use such a large ratio of Diethylamine?
Other procedures, such as the "POCl3-Shulgin" method only use 5x amounts of Diethylamine.
Any comments? Thanks. 		 
 
 
 
    Bubbleplate
(Hive Bee)
09-21-04 13:22
No 532481
       OK... Can Someone at least post the reaction     

Could someone lay out what occurs in the N,N-Carbonyl diimidazole procedure? I'm a cook, not a chemist!wink 		 
 
 
 
    n00dle
(Hive Bee)
09-21-04 16:35
No 532499
       Not sure if the CDI method is like the peptide     

Not sure if the CDI method is like the peptide coupling methods, but in peptide coupling methods only about 2 times excess amine to be reacted is utilized. The CDI overkill excess amine could possibly be to make sure that all of it reacts, as it's better to have leftover worthless amine rather than unreacted product, eh? (all methods have some ratio of over-excess amine, for this purpose, SWIM thinks.) 		 
 
 
 
    Rhodium
(Chief Bee)
09-22-04 05:30
No 532624
       CDI & DCC Coupling Mechanism     



Source: http://www.cem.msu.edu/~reusch/VirtualText4/special2.htm#top3
The Hive - Clandestine Chemists Without Borders 		 
 
 
 
    Bubbleplate
(Hive Bee)
09-23-04 03:36
No 532769
       Here's a Peptide Coupling Reagent Web Site     

Good info and References:
http://www.albmolecular.com/features/tekreps/vol04/no01/ 		 
 
 
 
    Bubbleplate
(Hive Bee)
10-09-04 14:28
No 535084
       Another Question Regarding Solvent For Reaction
(Rated as: good read) 		    

A few articles I've run across regarding Peptide Coupling Agents, (for instance http://www.peptide-and-dna.com/marder.pdf )
it is suggested that Choloroform or DCM may be better solvents  to carry out the reaction in. The above article says "If the activation is carried out in a solvent of low dielectric constant such as CHCl3 or CH2Cl2, the formation of {the carbodiimide} occurs instaneously...... However, if the activation is carried out in a more Polar solvent such as DMF, no immediate reaction can be detected and a complex mixture..."
My question is, while the article is about Peptide coupling, would this also be applicable to the Lysergic Acid/N,N-Carbonyldiimidazole reaction?