Author Topic: ET ---> Lysergic Acid  (Read 475 times)

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nevry

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ET ---> Lysergic Acid
« on: April 03, 2002, 09:08:00 PM »
hello all! below is a paraphrased section of Shulgin's LSD synth. The rest of it is pretty clear, i'm just having a few problem's with the conversion from ET to Lysergic acid

1a) dissolve 10g of ET in a aq soln of KOH(6.7g/100ml) at 75dC over the cource of 1h

wouldn't this temperature damage the alkaloid? Also, what happens when you heat lysergic compunds? Are they isomerized, or do they break down into something else?

1b) continue stirring for 3h, and cool to 10dC

2) acidify to ~3.0(pH) via 2.5N H2SO4(dropwise)(aprox 60ml H2SO4 was needed)

alright, steps 1a and 2 coverted ET to lysergic acid, but why did it fall out of the soln?

3) filter, wash w/ Et2O

4) dissolve solids in ethanolic 15% ammonia, stir for 1h

5) decant, repeat, combine, filter, evaporate

6) dissolve in 1% aq ammonia, acidify as above

7) wash precipitate with Et2O until 'clean'

again, why did it fall out of the soln?

thanks,
- nevry.


Here is the original synth if you don't feel like looking it up:

A solution of 6.7 g KOH in 100 mL H2O, under an inert atmosphere and magnetically stirred, was brought to 75 °C, and 10 g ergotamine tartrate (ET) added. The reaction mixture turned yellow as the ergotamine went into solution over the course of 1 h. The stirring was continued for an additional 3 h. The reaction mixture was cooled to about 10 °C with an external ice bath, and acidified to a pH of about 3.0 by the dropwise addition of 2.5 N H2SO4. White solids started to appear early in the neutralization; approximately 60 mL of sulfuric acid was required. The reaction mixture was cooled overnight, the solids removed by filtration, and the filter cake washed with 10 mL Et2O. The dry solids were transferred to a beaker, suspended in 50 mL 15 % ammonia in anhydrous ethanol, stirred for 1 h, and separated by decantation. This extraction was repeated, and the original decantation and the second extract combined and filtered to remove a few hundred milligrams of unwanted solids. The clear filtrate was stripped of solvent under vacuum, the residual solids dissolved in 50 mL of 1% aqueous ammonia, and this solution was acidified as before with 2.5 N H2SO4. The precipitated solids were removed by filtration and washed with Et2O until free of color. After drying under vacuum to a constant weight, there was obtained 3.5 g of d-lysergic acid hydrate, which should be stored in a dark, sealed container.

terbium

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Same as last month.
« Reply #1 on: April 04, 2002, 12:00:00 AM »
The answer is still the same as when you asked this question a month ago.

Post 273186

(nevry: "LSA ---> Lysergic acid", Tryptamine Chemistry)