psyloxy (Hive Addict)
05-07-04 19:23
No 505622
      H2SO4 + toluene --> p-tosic acid     

p-toluene sulfonic acid

110 parts toluene are sulfonated with 600 parts concentrated sulfuric acid at ordinary temperature. After all toluene is dissolved 250 parts ice or water are added with external cooling and stirring until the whole mass to solidified to a thick mash. Next the rxn mixture is vacuum filtrated. Crystalline p-tosic acid remains.

Patent DE57391

--psyloxy--
 
 
 
 
    Aurelius
(Active Asperger Archivist)
05-07-04 22:33
No 505645
      ordinary temperature?     

Do you mean 'room temperature'?  As in, needing no external source of heat?

(I presume this is what you meant as the details were scant.  Taking from your others posts, this means the procedure is damn easy.)

Act quickly or not at all.
 
 
 
 
    psyloxy
(Hive Addict)
05-07-04 22:39
No 505647
      gewöhnlich     

Ordinary is what the patent said, which is old fashioned for room temp. No other details were available from the text (the translation is 1:1), I presume that's because the authors took for granted everybody knew what the standard conditions of toluene sulphonation are, the invention doesn't directly relate to the production of tosic acid, but to the separation of the isomeres, the given example beeing a combination of both.

--psyloxy--
 
 
 
 
    psyloxy
(Hive Addict)
05-13-04 23:08
No 506950
      toluene + H2SO4 --> o-tosic acid (50% yield)     

Patent DE35211 preparation of ortho-toluenesulphonic acid

Toluene is sulfonylated by ordinary concentrated sulfuric acid with constant stirring at a temperature that must not exceed 100°C and regarded as finished as soon the top layer of toluene is gone. The mixture is decanted into cold water, neutralized with CaCO3, filtered off the CaSO4 and decomposed with Na2CO3. The water is removed by heating the mix. Content of the ortho-isomere : 40-50%.

See Patent DE57391 and Patent DE137935 for resolution of the isomeres. Basically the ortho is hardly dissolved by 45-55% H2SO4, the para by 66-71%, both are precipitated by cooling to become ~90% pure. Fractionated crystallization is the magic word.

note in the procedure in the post above the filtrate contains ortho-TsOH in amounts approximately equaling those obtained by the procedure here, both are essentially the same anyway.

--psyloxy--
 
 
 
 
    sYnThOmAtIc
(Hive Addict)
05-14-04 06:15
No 507047
      Orhto?     

What would happen to a glycol that is treated with ortho? Nothing? I was wondering if the p-tosic is contaminated, would it screw things up or should one just correct for the loss of the active p-isomer. So I guess my point woudl be, will the ortho do the same job, be inert in that type reaction, or screw sometign up(side reactions that aren't wanted causing loss in yield)?

Just wanted to be clear on what "essentally the same" means since I don't know what intended usage it is essentially teh same for.  Also will other sulphonated aromatics do teh same thing? Might try sulphonating xylene and doing a rearrangment if I find a procedure for its prep seeing as toluol is hard to get these days.

Edit:After a quick search it seems that xylens sulphonate is motre acidic than toluene sulphonate. Is that good or bad? Basically just want to know if it is practical or if it has ever been kown to work.


Type:10 cps Para-toluene sulphonic acid
Appearance:  Clear amber
Specific Gravity @ 25°C: 1.25 gm/cc
Total Acidity % 68-72%
Viscosity: 10 cps
Free Sulphuric Acid: 1.2% max.
Shelf Life @ 20°C: 24 months.


Type: Xylene Sulphonic
Appearance:  Brown
Specific Gravity @ 25°C: 1.27 gm/cc
pH 2
Free Sulphuric Acid: 3% max.
Total Acidity: > 90%
Shelf Life @ 20°C: 24 months.
 
 
 
 
    psyloxy
(Hive Addict)
05-14-04 06:49
No 507052
      clarification     

What's the stuff useful for ? __> Post 506492 (psyloxy: "o-cresol from potassium o-toluenesulphonate", Methods Discourse)

'Essentially the same' meaning: both procedures are sulphonylations of toluene with conc. sulfuric acid at relatively low temperatures, both producing a ~45%/55% mixture of ortho and para-isomeres, in the first one the para is isolated, while the ortho stays in solution, in the second one it's the other way around.

--psyloxy--
 
 
 
 
    acx01b
(Stranger)
05-18-04 02:07
No 507795
      somebody has some informations about the use...     

somebody has some informations about the use of ptsa in imines synthesis ?
(toluene amine ketone and a few ptsa is refluxed in Dean-stark)

imine can also be prepared without refluxing:
amine+ketone+drying agents
drying agents can be molecular sieves, MgSO4, CaCl2, KOH...

what about the use of small amount of conc. H2SO4 and toluene, or directly ptsa?
amine + ketone + drying agents + 1ml Conc. H2SO4 + 5ml toluene

maybe it reacts faster ?
 
 
 
 
    moo
(Hive Addict)
09-30-04 16:11
No 533905
      Toluene + H2SO4 + I2 (cat.) --> 90-95% p-TsOH
(Rated as: excellent)
    

Here is an golden oldie method for synthesizing para-toluenesulfonic acid avoiding the formation of the a bit difficultly separated ortho-isomer. It might come in handy when separating nitrotoluene and toluidine isomers from each other too - remember that sulfonic acids can be desulfonated in more dilute sulfuric acids (70-80% concentration IIRC).smile

J. Chem. Soc. 117, 1405-1407 (1920):




The Catalytic Action of Iodine in Sulphonation. Part I
By Jnanendra Nath Rây and Manik Lal Dey


The present investigation was undertaken with the view of ascertaining whether the addition of a trace of iodine to sulphuric acid (D 1.84) facilitates the sulphonation of aromatic compounds (compare Heinemann, Brit. pat 12660 of 1915 (Patent GB191512660)). It has been found that ordinary sulphuric acid and a trace of iodine can be advantageously used in place of fuming sulphuric acid with or without the addition of phosphoric oxide, etc. The nature of the product is changed in certain cases, thus making easy the preparation of some of the acids difficult to obtain. The catalytic sulphonation is facilitated by the presence of an amino-, hydroxy-, or halogen group in the molecule, but proceeds with less ease in the case of carboxylic acids, and is inhibited in the case of nitro-compounds. This fact probably explains the non-formation of disulphonic acids in the product. It is significant that there is an optimum temperature for each reaction in which maximum transformation takes place. It has also been noticed that there is some liberation of iodine vapour, but no trace of sulphur dioxide or hydrogen iodide could be detected in the space above the reaction mixture.
        The discrepancy between the actual yield and that theoretically possible was accounted for in nearly all cases by the unchanged original material.

Experimental

        In the experiments to be described below, the general method of work was to heat a mixture of a few grams of the substance and the calculated quantity, or an excess, of sulphuric acid (D 1.84), together with a trace of iodine, for a few hours at the temperature, determined by trial, at which the transformation was greatest. The product was poured into water, the free sulphuric acid removed with barium carbonate or hydroxide, and the acid liberated from the filtrate by exactly neutralising with sulphuric acid. The solution of the free acid was concentrated, whereupon it was obtained in a crystalline condition. In some cases the product was poured into a saturated solution of potassium chloride, when the potassium salt separated in fine crystals (o-nitrophenol, etc.). The acid of the potassium salt was converted by the usual method into the sulphonyl chloride from which the amide, mercaptan, etc., were prepared in order to characterise it. Some of the sulphonic acids described gave colour reactions with ferric chloride and characteristic salts with heavy metals. When the acid could not be satisfactorily identified, it was transformed through its amino- or nitro-groups, etc., into the corresponding hydroxy- or amido-compounds, etc., in order to establish its constitution. In some cases it was found convenient to extract the sulphonic acid from the sulphonated mass with alcohol (o-toluidine).
        The results obtained from the fusion of the products with potassium hydroxide were not taken into account unless substantiated by further evidence.

Sulphonation of Benzoic Acid


        A mixture of 12 grams of benzoic acid, 9 c.c. of sulphuric acid, and a small crystal of iodine was heated at 175-180° for about six hours, at the end of which time no free benzoic acid separated on diluting a sample. The liquid, after cooling, was poured into water, when a clear solution was obtained. The solution was neutralised with barium carbonate, the precipitated barium sulphate filtered off, and the filtrate exactly neutralised with dilute sulphuric acid. After filtering, the liquid was concentrated to a syrup, and, on keeping in a dessicator, crystals were obtained, which were drained, washed with a small quantity of alcohol, and dried over sulphuric acid in a vacuum. The anhydrous crystals melted at 134-135° (uncorr.), and were hygroscopic.
        A test experiment was conducted side by side with the above in which no iodine was used; almost the whole of the benzoic acid was recovered unchanged.
       The crystals in aqueous solution gave a reddish-brown coloration with ferric chloride, but no precipitate, and were identified as o-sulphobenzoic acid by the formation of salicylic acid when fused with potassium hydroxide at a moderately low temperature (Found: S=15.0 per cent. Calc for acid + 1H2O: S=14,57 per cent.).
        In the above experiment a gram of benzoic acid sublimed away, and was thus not sulphonated.
        The following table gives a résumé of the results obtained with other substances:

Substance Products by known methods By the present method Yield, per cent. Optimum temperature Time of reaction, Hours.
Toluene o- and p-acids p-acid only 90-95 100° 1
Benzoic acid m- and p-acids o-acid Above 95 175-190° 6
Phthalic acid - no product - - -
Catechol 3-acid 4-acid 75 50-55° 1
Quinol mono- and di-sulphonic acids mono-acid 73 70° 4
o-Nitrophenol p-acid p-acid 70 120° 5
p-Nitrophenol o-acid o-acid 50 100-105° 5
Nitrobenzene - no product - - -
m-Dinitrobenzene - no product - - -
o-Nitrotoluene p-acid p-acid 70 150° 5
p-Nitrotoluene o-acid o-acid 5 140° 4
o-Nitroaniline p-acid p-acid 60 125°
p-Nitroaniline o-acid o-acid 50 140° 3
3-Nitroaniline 6-acid 6-acid 10 150°
o-Toluidine 5-acid 5-acid 60-65 150° 3
p-Toluidine - no product - - -
Chlorobenzene o- and p-acids p-acid 85 110°
Bromobenzene o- and p-acids p-acid 85 100° 2


Summary and Conclusions.


        (1) Iodine acts as a positive catalyst in sulphonation.
        (2) Catalysis takes place smoothly when hydroxy-, amino-, chloro-, bromo-, or carboxy-groups are contained in the molecule, but with difficulty, or not at all, with nitro- or sulphonic.
        (3) There is an optimum temperature for each substance when the maximum temperature takes place.

        We have much pleasure in according our best thanks to Sir P.C. Rây for the interest he has taken in the work.

College of Science, University of Calcutta. [Received, January 28th, 1920.]

fear fear hate hate
 
 
 
 
    phenethyl_man
(Hive Bee)
10-10-04 21:56
No 535227
      substituted toluhydroquinones from o-cresol     

The sodium salt of o-toluenesulfonic acid should also be able to be used in the fusion w/alkali to produce o-cresol.

toluhydroquinone from o-cresol in 95%+ yields through acetylation to 3-methyl-4-hydroxyacetophenone and subsequent oxidation w/hydrogen peroxide.

Patent IE904369

substituted hydroquinone acetals (i.e. toluhydroquinone monoacetate) through acetylation followed by oxidation w/ a percarboxylic acid.

Patent FR2655335

Any use for toluhydroquinone monoacetates? Perhaps in the preparation of "tweetios" of DOM..?  (which were so elegantly named "Florence" and "Iris" by Shulgin)

It's too bad there is no route to MMA from o-cresol (or at least I can't think of one.)  It would be impossible to introduce an aldehyde group para to the methyl due to the para-activating effect of the hydroxyl.  However, perhaps iso-MMA would be interesting.  Anyone have any literature on 3-methyl-PMA (3-methyl-4-methoxyamphetamine)?

If you formylated first, you could get p-tolualdehyde in high yield from the Gattermann formylation on toluene at high temperature.  I'm not sure if p-tolualdehyde could be sulfonated but even if it could, the fusion w/alkali would undoubtedly yield 3-hydroxytoluic acid.  Which I guess could be reduced to the alcohol with LAH and oxidized to the aldehyde but why bother?

- phenethylman -