This quite a complex and tedious old procedure here.
The most convenient approach would depend on the temperature envisioned for the conversion process. At low to moderate temperature (<100c), p-TSA could be pre-dried b boiling in a solvent above 105c, using either a dean stark to collect water, or a solvent which boils at higher temp and just letting the water escape.
For higher temperature process (>100c) p-TSA could simply be oven dried for few hours, then the melt directly added to the material.
I think you guys are confusing anhydrous PTSA (letâs call it Nonohydrate) and its anhydride just like @Dr_Jebril did.
Anhydrides are not Brønsted acids.
You might sure get some CBD isomerization when using PTSA anhydride due to PTSA Nonohydrate being formed from the reacted anhydride, but youâre going to lose a stoichiometric amount of CBD to tosylation. Either way, using PTSA anhydride is a stupid idea when PTSA Nonohydrate will do the trick and youâre losing half the anhydride and equal amount of CBD to tosylation.
I took offense at the use of the word stupid, kinda put your whole explanation in a bad light.
I dont think it was a stupid thing to try. And even after your explanation it doesnât seem stupid.
Edit: Uneducated would have been an acceptable alternative I believe, and really more accurate.
If it is only the monohydrate that is causing conversion, At least the Anhydride is acting as a buffer to tie up any water that may be in/or enter the rxn.
Losing half a percent of CBD to tosylation seems like an acceptable loss to make the task of working in dry conditions easier.
Would tosylated CBD be toxic? Would it be removable using ab/dsorbents or distillation?
I like you because youâre smart man. But you can also sound condescending. Just keep it in mind, because you will see Iâm not an overly opinionated guy and will listen but the delivery has to be on point.
is that when ur dogging yer girl from behind and she got hair on her back? merry xmas brah
i explicitly called the idea stupid, not anyone trying it, and even explained why in the very same sentence.
Also because PTSA anhydride is 20x the price of PTSA and the same outcome can be had for way less money and a little bit more preparatory work.
Thereâs the Monohydrate, thereâs the Nonohydrate (=Anhydrous acid), and thereâs the Anhydride (which unlike the other two is not a Brønsted acid).
The former two catalyze isomerization, the latter doesnât do so directly, but only by reacting with water or hydroxy group bearing substrates and the subsequently released anhydrous acid.
Not knowing that, can you still say with certainty that itâs not a stupid idea to use PTSA Anhydride?
This additional work is negating the questionable advantage of using PTSA Anhydride.
Fair enough, I misinterpreted that a little. Still, I donât feel it was a stupid idea.
I would say price is largely irrelevant at least at the price range we are talking about.
The idea behind using the anhydride was to achieve anhydrous conditions. Is there anyway to get anhydrous/nonohydrate PTSA from the monohydrate?
I am glad that you informed everyone and Iâm glad this was for R&D and wasnât for clients. But the idea to try it wasnât stupid.
Is it really additional work if we are already filtering and distilling anyway
So when the Anhydride interacts with H2O the H2O is consumed yielding Anhydrous PTSA, as you have stated. PTSA.H2O is slightly soluble in toluene. When the monohydrate dissolves, its H2O of crystallization is released. With how important it is to work with dry conditions, this seems like a pretty significant advantage of the Anhydride over the Monohydrate.
Also it sounds like we got exactly what we wanted, Anhydrous PTSA. We just didnât understand what was happening. Im not aware of any way to get rid of the water of crystallization from the PTSA.H2O.
So you have convinced me that we arenât educated, but I was already well aware of that.
I still donât think it was stupid to try, in fact you educating us on what was happening has only reinforced my belief that it was a smart thing to try.
Now, if you tell me theres a way to get Anhydrous/Nonohydrate from the Monohydrate, and that this method can be readily found on the internet, then I will agree it was stupid to try the Anhydride.
this i have never stated anywhere and also never intended to express, because itâs far from the truth.
just because i use strong words a lot and generally have poor manners doesnât mean i think iâm surrounded by idiots (there are a few though, mostly those with royal and tribal titles). you know the saying, âif youâre the smartest person in the room, youâre in the wrong roomâ and i am certainly neither the smartest/most knowledgeable person nor in the wrong room.
merry xmas brah