I guess that's possible. Though I can tell you from SWIM's experience that 2 different reactions, one in which the HTA was added over a much longer period, & allowed to stir for longer as well, seemed to yield identical results, as far as SWIM could tell.
The Danilov article mentions the formation of condensation products, which break down when the acid is diluted. SWIM definitely noted that upon pouring the reaction product over crushed ice the dark brown color disappeared, to be replaced by some sort of whitish stuff that wasn't soluble in water (nor in the dilute acid mixture). The stuff looked sort of like you'd imagine little pieces of white bread might appear after they had been floating in a jug of water for so long that they'd broken down into little semi-fibrous drifting stuff (note the high-tech analytical descriptive analogy I so skillfully deployed there
).
When toluene is added, it dissolves the whitish stuff, which seems like it could definitely be problematic, as whatever it is (I assume some sort of by-product of the breakdown of the "condensation products", but I don't know what it is) is now mixed in with the P2P which is hoped to be there. So I wonder if it might be filtered out before the toluene extraction.
But I also wonder whether it might be bonding to the P2P to some extent -- because otherwise I would think that the P2P would separate from the dilute sulfuric solution... but leaving a sample of the reaction product / dilute sulfuric solution overnight did not show any separation (note, however, that the whitish stuff was not removed before letting it stand).
I have a feeling that this stuff is floating around in there with the P2P, and then after the solvent is removed, and with further heating during distillation, some sort of complex is reforming. It definitely seemed like there was a sudden reversion to the brownish color while trying to distill the P2P from what was left after removal of the toluene.
I note that Jan1983 (and it seems as if someone else said the same thing in another post, I'm not sure) just used the crude product left after removal of the toluene as if it were the pure product, in completing the synth to meth. Maybe that's the way to go, as I suspect that the water/alcohol mixture used in the standard methylamine/P2P synth would inhibit the formation of the unwanted gunk (SWIM's attempted distillation of the reaction product after the HTA/H2SO4 synth left a rock-hard amberish substance glued to the bottom of the flask, which only seemed to dissolve completely in acetone. Upon pouring out the acetone into the sink, SWIM observed that the acetone with the dissolved gunk in it, which was a dark reddish-brown color, immediately turned white upon mixing with some standing water in the bottom of the sink... my take on this is that these same "loose complexes" that were broken down when pouring the reaction product over ice & allowing it to melt, reformed once they were free of the water & able to come into contact with the P2P again (when taken up into the toluene). Washing the toluene with water didn't help; but when in the acetone, which is miscible with water, water again broke the stuff up. So maybe the same thing would happen in the water/alcohol mixture used in the meth synth, the water allowing the P2P to break away from whatever it's bonding to.)
Alternatively, I was thinking that the P2P might be extracted from the stuff before distillation, as a bisulfite adduct, as mentioned here:
https://www.thevespiary.org/rhodium/Rhodium/chemistry/p2p.phenylacetic.html
Chemical separations were conducted by means of a bisulfite addition complex and Girard's reagent T. The aqueous sodium bisulfate extraction of the reaction mixtures removed most of the P2P present; however, higher ketones do not produce bisulfite adducts as easily because of the sensitivity of the additions to steric hindrance45. The water-soluble bisulfite-P2P addition product may be hydrolyzed with strong acid or base to regenerate P2P for examination. The nonbisulfite retained compounds were reacted with Girard's reagent T, a material known to react with ketones to also form water-soluble adducts, which allows separation of ketonic and nonketonic compounds. An organic extraction allowed clean isolation of all nonketonic compounds into an organic phase.
That Girard's reagent T stuff sounds promising, as well, heh... though it sounds like it's really not needed for P2P, and that a sodium bisulfate extraction would work... though, again, if the P2P is already tied up in some sort of complex, I'm not sure whether it would react to form the bisulfite adduct...
*sigh*. SWIM plans next time to just take the viscous liquid left after removing the toluene & toss it in to the Al/Hg/Nitro synth. Maybe this is all much ado about nothing.
p.s. Please forgive my (undoubtedly) awkward way of describing my questions / problems / ideas about this stuff. I'm well aware that I don't know squat about chemistry compared to a lot of people here, and so am not sure when whatever ideas I'm trying to express might be either ridiculous errors in understanding, or painfully obvious restatements of already well-known concepts that everyone else, as a matter of course, takes as a 'given'. But I do my best to work things out using what little I do know, and what I'm able to gather from the research & ruminations of other bees who appear to know what they're talking about a lot more often than I do. So thanks for all the help, peoples, and please bear with me.