fardoubt - 2-5-2006 at 10:00
I've been searching for a suitably high boiling solvent for an amino acid decarboxylation for some time now. I ran across a pet supplement that has a
sufficiently high boiling point. It is comprised of near pure dimethylsulfone. Might this be an acceptable alternative for a nonpolar solvent, such as
napthalene or diphenylmethane? Or is the nonpolar nature and presence of phenyls on these other solvents the precise trait that makes them suitable
for this sort of application with aminos such as tyrosine?
-FarDoubt
solo - 2-5-2006 at 16:22
Did you google and miss this?......solo
Excerp....Decarboxylation in Diphenyl Ether1 DL-Tryptophan (1.0 g) and diphenyl ether (50 ml) were heated at reflux for 1 hour in an
atmosphere of nitrogen. The mixture was cooled and extracted with 2N aqueous hydrochloric acid (3x40ml). This extract was washed with ether, basified
(6N NaOH), and extracted with ether (5x50ml). This extract was washed with water and brine, dried over sodium sulfate, and the solvent removed in
vacuo, leaving a residue which was recrystallized from benzene to give pale yellow prisms (530mg), mp 113-114°C. Sublimation afforded a colorless
crystalline solid (450mg, 57%), mp 114-115°C.
The use of freshly distilled tetralin as the solvent for decarboxylation led to a yield of only 36%. With commercial tetralin the yield was reduced to
20%. No tryptamine was isolated from experiments which employed diphenylamine or dimethylsulfoxide in place of diphenyl ether.
.................source,
http://designer-drugs.com/pte/12.162.180.114/dcd/chemistry/t...
[Edited on 3-5-2006 by solo]
fardoubt - 2-5-2006 at 17:07
I actually have perused that very source and found that most of the successful decarboxylations dealt with non-OTC solvents. That source indeed states
that dimethylsulfoxide (BP=196 C) does not work in the reaction. Dimethylsulfone has a sulfonyl rather than one double bonded oxygen. Its boiling
point is 236 C, about 40 degrees higher than that of DMSO. Since this is a thermal decarboxylation, is there any rational in giving this a try because
of this higher boiling point?
I've also uncoverd a source for biphenyl (BP=255 C) which seems to me to be a great possibility for this experiment, although I have found no
references with regard to it in any literature.
solo - 3-5-2006 at 03:22
Have you looked at the thermal decarboxylation thread regarding decarboxylation using Iron......................solo
https://sciencemadness.org/talk/viewthread.php?tid=3459