red P vs phosphinic acid vs phosphonic acid; HI vs I2

DnBGirl · Tue Jun 28, 2005 10:08 pm

loki : All right! Also I recently read that H3PO3 and H3PO2 will produce lower quality ----. If it is true is this for the same reason as with H3PO4? Im little confused, so H3PO4 can work? Will be still better use RP/I instead of H3PO4? I ever though that it doesnt matter what route I will get HI? It seems that pure red fosforus will be better than its gases.

hazzbeen: I read KI/phosphoric acid from the HIVE, I wanted to try it, although never before heard about this. My people dont use KI only I. Was it this procedure?

https://www.synthetikal.com/hiveboard/crystal/000271993.html#Post271993

hAzzBEEn · Tue Jun 28, 2005 10:24 pm

I've heard that Hypophosphorous acid & and Phosphorous acid reductions produce superior product.
Either method will probably produce top notch goods as long as it is done correctly.

loki · guinea pig

DnBGirl, i don't think that phosphoric acid will let any desoxyephedrine be produced. Knowing the reaction processes that can occur, it is my opinion that hypophosphorous and phosphorous acid will actually produce better quality material because the hypo/phosphorous acid immediately reduces the iodoephedrine. this is why it's faster, and theoretically it should be cleaner product and higher yield. the red phos reaction proceeds via a reaction between iodine and red phosphorous that proceeds through a phosphorus halide i believe. I don't understand why there hasn't been a definitive study on the kinetics of the reaction to determine exactly what things occur. phosphorus triiodide would strongly iodinate ephedrine and convert into phosphoric acid, for one thing, but also hypophosphorous and hydriodic acid can form as well. it is partly because of the mystery surrounding the phosphorus/iodine reaction system that i started this thread.

DnBGirl · Wed Jun 29, 2005 10:36 am

Can GAA be used instead of water? I am not sure, I have to sleep, but think that tonight some post...phosphoric acid is the same. Its possible works only as water, main reactin provide red phosphorus. It would explain why they dont use water.
Would this be real? H3PO4 instead of H2O. How this can change resulting product?

loki · guinea pig

yes GAA is fine.

both H3PO4 and GAA don't react with the phosphorous and iodine molecules in the reaction and thus can be used to increase the amount of solvent and spacing around the reacting substances. GAA (100% acetic acid) and 100% H3PO4 cannot be used to subsitute for water however, otherwise the HI acid will fume out of the reaction vessel. (HI acid needs to be in the narrow band of concentration between about 50 and 57% to perform the reaction, if there is no water the reaction cannot occur because the HI is not dissolved properly). These acids will contain the gaseous HI that forms to some degree but HI will not perform the reaction without water, or at least will do it extremely vigourously (ie dangerously, ie side products). Try to ensure that the reaction will contain approximately the right amount of water proportional to the HI acid that will be in the reaction so it's at 57% concentration all the time. I think it is something like a 1:3 rato of HI to H2O in concentrated HI acid (57%)... HI is 127.9g/mol, H2O is 18, so the ratio is there should be 43% H2O, bringing it down to lowest common denominators that means that if one has 127.9g (1 mol) of HI acid there will be 3.05 moles of water in there.

I'm not absolutely certain about this tho, it's equally possible that HI works better in anhydrous conditions - in GAA at least the reflux temperature is about 120 which is perfectly within the range of reactivity of the phosphorus compounds, which are reactive between 100 and 130 degrees C (this range is due to the fact that they decompose at these temperatures, decomposing molecules are what reactions are driven by)