The Hive > Methods Discourse
from photo developer to potent hallucinogen
phenethyl_man:
That does not seem to be a problem if you run the decarboxylation at a low enough temperature and do it in a two phase mixture (aqueous/toluene). The aldehyde goes into the toluene as it is formed. This is speaking from personal experience.
Oh, and use a crystal or two of sodium nitrite to kick start the decarboxylation reaction if you need to. There is no need to use any hydrochloric acid as is suggested in one patent on the Hive.
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yeah, I noticed one patent used almost 1 mol equiv NaNO2 per mol of substrate but equal yields were obtained in another procedure which didn't utilize any..
the two-phase rxn sounds like a good idea, thou the consensus appears to be that 50 degC is the magic number i.e. as long as the temp doesn't rise above that then only the mandelic acid chain will be attacked..
too bad my friend has no more glyoxylic acid, there's a bunch of 2,5-diMeo-toluene that wants a formyl group real bad. anyone actually tried the oxalic acid al/hg reduction referred to in this Post 427038 (foxy2: "Preparation of Glyoxylic acid", Novel Discourse)? I imagine the post rxn workup is not too friendly..
Maybee will try that modified duff w/TFA, but damn that shit is pricey..
phenethyl_man:
well, since this rxn also involves a photo chemical to phenethylamine (THQ->DOM), I will consider it on topic..
A stirred solution of 4mL formalin, 20mL hydrochloric acid, and 80mL acetic acid was saturated w/HCl gas until it would absorb no more (this took about 5-10 min). 7g of 2,5-dimethoxytoluene was then added dropwise at a moderate rate. The rxn was suprisingly exothermic as hell and HCl gas began to evolve out of the soln as it heated up. Once breathing became difficult the addition was accelerated somewhat so SWIM could get the hell out of there. The addition took about 15 minutes and the exotherm ceased about 5 minutes later. At this point the soln was full of a white precipitate and quenching the reaction in 250mL dH2O caused even more precipitation. The solids were quickly filtered and the area quickly evacuated..
I fear it is the disubstituted product but it seems as if all the 2,5-dimethoxytoluene reacted and there wasn't really enough CH2O to react twice so we will see.. coming soon: a melting point test which should tell the rest of the story.. The plan is to react it w/sodium 2-propanenitronate to give the benzaldehyde which has always given 70%+ yields in the past on alkyl-substituted benzyl halides..
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