Why is the Garbrecht synthesis favoured by many chemists? I always thought that the Jacobs et al or the Shulgin methods wore the clandestine chemist favourites.
In this post it isn't even mentioned
Post 250385
(halfapint: "Re: First LSD Synth Post", Tryptamine Chemistry)
Re: First LSD Synth Post Bookmark
responding to the TOTSE site LSD synth question
There are three LSD synths there. (These, and more, are at Rhodium's.) The first is Hofmann's original method, hydrazide to azide, which yields a racemate which then has to bee rectified, not fun, low yields. The second uses unobtainable reagents and unrealistic conditions. If you got any trifluoroacetic anhydride on you, grab a quick shower. The third is the shits, Garbrecht's synthesis, high yields, fast and easy.
The problem is that the procedure given does not contain enough information to successfully carry it out. Nor does the Garbrecht synthesis on Rhodium's page. Both lack the crucial information that the synthesis is extremely sensitive to the exact equivalents of SO3 to lysergic acid. You must have precisely 3 equivalents, or you're spinning your wheels; yield falls to near nothing, if your measurement is off the slightest bit.
About those yields. This paper says that Garbrechts method yields 50%.
Post 450823 (missing)
(Aurelius: "Cland Drug Labs J. For Sci 15,1, 51-64 (1970)", General Discourse)
Cland Drug Labs J. For Sci 15,1, 51-64 (1970)
Lysergic acid diethylamide: Conversion of d-lysergic acid to LSD can be accomplished, theoretically by any common procedures for the formation of amides. The procedure described by Garbrecht (3) appears to be most favored. In this method, 9g of d-lysergic acid monohydrate will have a theoretical yield of 10g of the tartrate salts of LSD. [/red]The actual yield is about 50% of theoretical.[/red]
In Valentines psychedelic book the yields of Garbrechts method are suddenly higher then 50%
The following methods all proceed from lysergic acid (I). Methods 1, 2, 4, and 6 give less than 20% iso-LSD in the product but methods 2, 5, and 9 seem to have the highest total yield (about 80%) of LSD plus iso-LSD. Since unreacted lysergic acid can be recovered and run through the synthesis again, and iso-LSD isomerized to LSD as described here, it is probably best to use the simplest methods. These comparative yields come mostly from the reference to method 9.
In which the Garbrecht method is method 2.
What yield can I get with the Garbrecht method. When it is 50 % the it's better th do the POCl3 method because that also yields 50 % only it's alot faster and easier.
What is true!!?? I getting really confused here and everytime I find something, something new appears that makes me even more confused.
By the way. How big-scale can you go with the POCl3 method. Is 300 gram LSA in 1 reaction a problem for this method?
