Author Topic: H2O2 o-cresol to 2,5-dihydroxytoluene, 98%  (Read 1691 times)

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psyloxy

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H2O2 o-cresol to 2,5-dihydroxytoluene, 98%
« on: May 06, 2004, 12:03:00 PM »
JOC 65,8.2000 - 2348 - Lot's a thanks to ning who retrieved the article!

Reaction of Phenol with H2O2 catalyzed by Cis-Cu.

cis-Bisglycinato copper(II) monohydrate (50mg, 0.225 mmol), phenol (473mg, 5.32 mmol), and H2O2 (1ml, 30%)
were mixed together in a flask and stirred at room temperature. The white paste obtained slowly turned brown, and
the color intensified with time. After 24h of continuous stirring, the reaction mixture was washed
several times with petroleum ether (4 x 20ml) to obtain a paste, and this paste was washed with water (1ml) and dried
in evacuated desiccator to obtain a black solid (0,24g).

Reaction of o-Cresol. Similar reaction of o-cresol
(540 mg, 5 mmol) with H2O2 (1ml 30%) and cis-Bisglycinato copper(II) monohydrate (50 mg, 0,225 mmol) gave
2,5-dihydroxytoluene in 98% yield

o-cresol from phenol, HCOH and Ca(OH)2:

Patent US2401608



preparation of cis-Bisglycinato copper(II) monohydrate
1. Weigh, to the nearest 0.01 g, 4g of copper (II) acetate monohydrate and place in a 250 ml flask. Add 40 ml of H2O and heat, with stirring, until the salt completely dissolves.
2. Keeping the solution warm, add 40 ml of hot 95% ethanol to the flask.
3. Weigh out 3 g of glycine and place in a 50 ml beaker. Add 40 ml H2O and heat until dissolution occurs.
4. Add the hot glycine solution to the hot copper solution and swirl.
5. Cool the flask in an ice bath until the product precipitates.
6. Collect the product using a Büchner funnel. The filtrate may be used to rinse out any product remaining in the flask.
7. Wash the product once with approximately 60 ml of 95% ethanol.
8. Suction dry the product for a few minutes, then put on a watch glass and dry in an oven at about 50ºC for 40 minutes.
9. Weigh the final, dry product and place in a pre-weighed vial (with cap).

Ref:

http://wwwchem.uwimona.edu.jm%3A1104/lab_manuals/c31lex1.html



--psyloxy--

psyloxy

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o-cresol from potassium o-toluenesulphonate
« Reply #1 on: May 11, 2004, 01:31:00 PM »
Zeitschrift fuer Chemie 1869; p618

50g potassium o-toluenesulphonate and 150g KOH are molten in an iron pot/shuck, the molten mixture dissolved in water, treated with HCl, the dopped out o-cresol extracted with ether, the extract dried over CaCl2, the ether stripped off and the left over o-cresol distilled in a carbonic acid stream. (<__ What's that ? Steam distillation w/ added CO2 ?)

yield: 62% (16g o-cresol from 50g o-TsOK)
--psyloxy--

moo

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I assume it means that it is distilled in a...
« Reply #2 on: May 11, 2004, 02:21:00 PM »
I assume it means that it is distilled in a CO2 atmosphere to prevent oxidation.


ning

  • Guest
Oh, there's going to bee some DOM a'cookin!
« Reply #3 on: May 11, 2004, 10:29:00 PM »
psyloxy, that's awesome!

Actually, almost anything can bust a phenol to a benzoquinone...MnO2, KMnO4, HNO3, I believe bleach can do it, and possible H2O2 with MnO2, Iron salts, or Copper salts. That funky ligand may not bee necessary.

This is really much better than the nitration way, because you don't have to distill nitrotoluenes! Cool.