(Hive Addict)
05-06-04 17:11
No 505319
(Rated as: good read)
TsOH + MeOH + Fe3+-montmorillonite ___DCE___> TsOMe ; 80°C, 3h, yield: 82%
Tetrahedron 56 (2000) 7291 - 7298--psyloxy--
toluenesulphonate tosylate tosylation tosic ester
(Active Asperger Archivist)
05-07-04 06:24
No 505511
I remember a bunch of posts a while back concerning this, but am too lazy to look it up right now.
Act quickly or not at all.
(acetaminophanatic)
05-07-04 07:15
No 505524
Hmmm, I wonder too...what could a safe-to-handle, efficient, {kind of OTC} methylating agent bee good for? Hmmm.....
I guess nothing, unless one is in the habit of methylating syringaldehyde or hydroquinones...
Good find psyloxy!
(I wonder what the trick is?)
...it's an AOL chatroom for dyslexic spider monkies...
(Hive Addict)
05-07-04 17:39
No 505605
Preparation of Catalyst
To 1L of 1M aqueous FeCl3 solution, 80g of K10 montmorillonite was added. Stirring was maintained for 16 - 30h in order to saturate the exchange capacity of K10 montmorillonite. The clay suspension was centrifuged and the supernatant solution was discarded. The clay catalyst was washed each time with fresh distilled water until free of chloride ions as indicated by AgNO3 test. The catalyst was dried overnight in an oven at 120°C and finely ground in a mortar.
Tosylation of Cyclohexanol, General Procedure
To a solution of cyclohexanol (0.3g 3 mmol) and p-toluenesulfonic acid (0.57g, 3 mmol) in 1,2-dichloroethane (20mL), Fe3+-montmorillonite (0.1g, 0.075mmol of exchanged Fe) was added and refluxed in a two-necked flask equipped with a Dean-Stark apparatus. The reaction was complete in 3h (monitored by TLC). The solvent was removed under reduced pressure and the product was column chromatographed (2% EtOAc/pet. ether) on a silica gel column to afford cyclohexyl tosylate (0.655g, 86% yield).
For methyl/ethyl/propyl - tosylate the reaction mixture was filtered and extracted with water to remove the unreacted tosic acid, then evaporation of solvent gave chromatographically pure products.
All reactions were run in flame-dried glassware under a nitrogen atmosphere.
Table 1: Tosylation of cyclohexanol.
| Solvent | Time(h) | Yield (%) |
| DCE | 3 | 86 (85)e |
| Toluene | 3 | 32f |
| n-Heptane | 4 | 86 |
| n-Hexane | 6 | 84 |
e: Yield obtained with catalyst already used 5 times
f: Cyclohexyltoluenes were obtained in 65% yield (ortho/para=2:3) by 1H NMR
Table 2: R-OH + TsOH __DCE, reflux__> TsO-R + H2O
| Alcohol | Time (h) | Yield (%) |
| MeOH | 3 | 82b |
| EtOH | 2 | 78 |
| PrOH | 5 | 75 |
| allyl alcohol | 2 | 88 |
where to go from here ? __> Post 458190 (Lego: "Some alkylations with alkyl tosylates, Pt. 2", Novel Discourse)
--psyloxy--
(acetaminophanatic)
05-07-04 18:16
No 505611
with that 80 g or whatever of catalyst, I wonder how much mescaline could bee made?
psyloxy, I know you thought it was a bad idea, but I want to repeat here for all the bees that naphthalene can be sulfonated to produce "napsic" naphthalenesulfonic acid, which I bet could be substituted for tosic acid. IIRC, producing tosic acid requires either high temperatures or oleum. If there is interest, I can look it up again.
Too bad they need a 10 x excess of methanol. Probably it could bee recovered and reused.
I wonder if PTC could accelerate this reaction?
Well done! And here ning was going to make a methyl chloride generator!
...it's an AOL chatroom for dyslexic spider monkies...
(Hive Addict)
05-07-04 19:25
No 505623
10 times excess ? They used 4 equiv. of MeOH, which isn't even necessary as demonstrated by the reactions with higher alcohols: if one equivalent is used yield is only a few percent less.
--psyloxy--
PS: Post 505622 (psyloxy: "H2SO4 + toluene --> p-tosic acid", Chemistry Discourse)
(acetaminophanatic)
05-08-04 18:02
No 505804
You have been busy....I stand corrected.
If only halfapint were with us now....
...it's an AOL chatroom for dyslexic spider monkies...
(Hive Bee)
05-09-04 22:01
No 506042
producing tosic acid requires either high temperatures or oleum
I made some TsOH from 35% sulphuric acid by first concentrating it as much as possible by the ordinary method (boiling off water under vacuum) and then following the procedure as described in Organikum (reflux with a Dean-Stark trap).
Actually there is much more work to purify the product than to make it. Needles to say that the xylenesulphonic acid is even less demanding while equaly useful. It can’t get more OTC than it already is.
“The real drug-problem is that we need more and better drugs.” – J. Ott