Well i'm afraid this rxn doesn't work at all
I still post the story of what SWIM did so that you guys (Rhodium?
) see if SWIM didn't fuck smth up.
p-Toluenesulfonic (tosic) acid (method taken from
http://zaratustra.narod.ru
)
In a 500 RBF equipped w/a reflux condenser SWIM placed 76 ml toluene and 45 ml conc. H2SO4. They didn't mix, duhh. This was immersed in an oil bath which was maintained at ~125 C during the rxn. The toluene never really started to boil, so SWIM just shook it occasionaly for an hour (don't take the condenser off! Toluene starts to boil as you shake it) - maybe 12 shakings were needed. At this point most toluene was consumed (26 ml left) and the bottom layer was brownish yellow. To this 170 ml of water and 1.7 g activated charcoal were added and some of the mxtr was distilled off until the distillate stopped smelling like toluene. The charcoal was filtered off at this point and the mxtr became clear and slightly green. It was further concentrated to 140 ml volume.
SWIM then put it in the freezer overnight and the next morning a little amt of crystals was observed at the bottom. The flask was immersed in an ice bath and saturated w/unhydrous HCl at 5-10 C. (Jesus, you should've seen SWIM's kitchen lab! All the equipment w/the xception of the (the only:) condenser is self-made
- you ever seen a self-made pressure-equalized dropping funnel charged w/conc. H2SO4? SWIM's consists of 2 flasks, 2 rubber stoppers, 4 glass pipes and a polyethylene crane that - get it -
leaks. It is a very fortunate circumstance though, cause when the bubbler pipe gets plugged up, you can see that sulfuric acid starts to drop out of the crane's handle faster... And so you can prevent the funnel from blowing up... SWIM must confess SWIM missed that particular moment once
- fortunately, with no disastrous consequences) Gassing surely has been the shittiest part of the experience for SWIM and, yes, it took a long while. When HCl was no longer sufficiently absorbed (i.e., it started to appear at the flask's mouth) the mixture was thick w/white crystals and intensely yellowish-green. The crystals were filtered w/sucction on a Buchner funnel, then washed w/a little ice-cold HCl, which removed the remnants of green from them and sucked as dry as possible. They were put in an exicator (guess what it looks like:) over conc. H2SO4 and solid NaOH. And there they still are - they should be dried for several days. SWIM didn't weigh them yet but the yield was decent.
But SWIM , being young and impatient, decided that since water is formed in the rxn anyway and HCl would very soon go away as CH3Cl (as indeed happened) he'd just take some of his wet tosic acid and proceed w/it. So he weighed out 22 g of it (2 g added for moisture) of it, dissolved in 100 ml CH3OH and dryed the soln. w/freshly pulverized Na2SO4 - an large excess was added and left in the flask to absorb the moisture that would supposedly be formed further. This was refluxed for 18 hours. The mixtr turned yellow and unclear. It was neutralized w/saturated aq. bicarbonate (~130 ml) (CO2 evolution was observed) and xtracted w/ 2x70 ml ethyl acetate, which removed all yellow color to the org. layer. The organic xtracts were separated and dryed w/Na2SO4.
Now SWIM doesn't have a vacuum so he just decided to boil the solv. off at ordinary pressure (ethylacetate bp 77 C, methyl tosylate bp 140 at 5mm) (bath set at 100 C), and when he did that all that was left in the flask was ~0.5 ml of dark brown gunk. Now, SWIM thought that maybe since they're both esters they might form an azeotrope or smth (SWIM doesn't know shit in chemistry;) and tried to evaporate the ethyl acetate from the distillate w/a hair dryer (a vacuum cleaner attached to the system as the fume hood
) - and that produced nothing else but 3 ml water (obviously SWIM didn't dry it well enough
) with some TINY oily drops at the bottom.
Well, ladies and gentlemen, looks like this approach doesn't work.
FUCK!!!
Well, maybe that methyl tosylate is so volatile that SWIM evap'd it all away but i highly doubt that
Still tosic acid is a useful reagent - it can be used in isomerizing THC. Also SWIM plans to try it as a TFA substitute in Duff formylation of dimethoxybenzene - that'd be really cool! If it worked...... SWIM is starting to get pessimistic - too bad for him!
BTW, can anyone w/an access to the library look up its pKa? I shall be REALLY grateful as i can't find it on the Web.
Antoncho