Vibrating_Lights (Hive Addict)
03-21-03 01:03
No 419738
      Diethylation and Debenzylation with acetylation  Bookmark   

To di methylate tryptamine we use Formaldehyde and NaCNBH4.  If you wanted to diethylate the tryptamine what aldehyde do you use.  Way newbee question.  Also in the psilocin synth on rhodiums site It appears that sodium acetate is employed during the De-benzylation to make the acetyl.  Is acetic anhydride not needed here?

4-Acetoxy-N,N-dimethyltryptamines fumarate (2)

In a 250 mL Parr hydrogenation bottle was placed 0.25 g of 10% palladium on charcoal followed by anhyd sodium acetate (1.50 g, 18 mmol). Benzene (50 mL) was added, followed by 4 benzyloxNNdimetnyltryptamine(0.50 g, 1.7 mmol). The mixture was shaken under 60 psig of hydrogen for 4 h. After the uptake of hydrogen had ceased the hydrogenation bottle was removed from the apparatus, the mixture was diluted with THF (25 mL), and the catalyst was removed by filtration through a pad of Celite 545. The catalyst was washed repeatedly with isopropanol (3 x 50 mL). The washings and mother liquor were collected separately because of unreacted Ac2O in the filtrate. The mother liquor was concentrated under vacuum to about one half the original volume, then toluene (50 mL) was added. The solution was again concentrated by rotary evaporation. The isopropanol washes were combined with the residue and also concentrated. The residue was then dissolved in anhyd MeOH (50 mL). Fumaric acid (0.198 g, 1.7 mmol) was dissolved in MeOH (10 mL) and added to the stirred methanolic solution of the residue. After stirring for 10 minutes, toluene (50 mL) was added and the solution was concentrated to dryness by rotary evaporation. Absolute EtOH was added to the residue and a white precipitate of 2 fumarate (0.290 g, 0.8 mmol) formed and was collected by filtration. The filtrate was evaporated and the residue was dissolved in a minimum amount of MeOH. EtOAc was added and clear crystals began to form. After storing the solution in a freezer at -10C, 0.170 g of additional product was collected for a total yield of 0.460 g (74.8%); mp 172-173C.
I was under the impression that Acetic anhydride was needed here.  will the sodium acetate work???
If so could thte debenzylation be done with the NaACOh with THF as the solvent????

Start thinking more like a chemist and less like a criminal
 
 
 
 
    Lilienthal
(Moderator)
03-21-03 07:20
No 419823
      Formaldehyde, acetaldehyde, propionaldehyde,...  Bookmark   

Formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, valeraldehyde... (C1 - C5 aldehydes)

quote:

The washings and mother liquor were collected separately because of unreacted Ac2O in the filtrate.


 
 
 
 
    Rhodium
(Chief Bee)
06-03-03 15:32
No 437637
      Correction to the article - Ac2O left out  Bookmark   

http://www.thieme-chemistry.com/thieme-chemistry/journals/info/show_pdf.html?thieme-chemistry/journals/info/include/pdf/synthesis/errata_ss_9906.pdf