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Topic: Conversion cyclic alcohols to tetriary amines  (Read 7780 times)

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Offline Nekromantis

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Re: Conversion cyclic alcohols to tetriary amines
« Reply #15 on: November 12, 2016, 07:25:22 AM »
Cl is a very bad leaving group. Better options would be to convert it to a Br or I, or more simply to mesylate or tosylate the alcohol (which you suggested the the p-TsCl). Dissolve that in DMF, add some K2CO3 and the amine. Heat may be necessary to facilitate reaction, but I've done lots of amine alkylations this way. Cl has never worked, I've always needed to swap it for a more labile leaving group.

In monday i will try make a reaction with p-toluenosulfonyl chloride. I found reaction where they used alcohol with p-toluenosulfonych chloride. Next step was dissolving imidazole in DMF and adding sodium. The heating reaction by 1 hour and they adding transformed alcohol. Byt result this reaction was not succesfull only 29%, but maybe this reaction with K2CO3 with cyclic amine eg. pyrrolidine will be better.


Quote
http://dergipark.ulakbim.gov.tr/tbtkchem/article/viewFile/5000024385/5000024622


This link is not working
Ph.D student of organic chemistry from Poland
Speciality: Ionic Liquids, Chiral Ionic Liquids, Diels-Alder reaction

Offline AWK

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Re: Conversion cyclic alcohols to tetriary amines
« Reply #16 on: November 15, 2016, 07:59:44 AM »
on my computer works
try alao
http://journals.tubitak.gov.tr/chem/issues/kim-10-34-2/kim-34-2-16-0903-46.pdf
or
10.3906/kim-0903-46 (DOI the second link in google search)
AWK

Offline Nekromantis

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Re: Conversion cyclic alcohols to tetriary amines
« Reply #17 on: November 21, 2016, 07:15:00 AM »
Today I made this reaction using K2CO3 in DMF, but i used pyrrolidine instead imidazole like was descriped in article: Eur. J. Inorg. Chem. 2015, 1604-1615.

But now I must clean the product.

1-(1S)-Menthylimidazole (1b):

To a solution of imidazole (13.2 g, 194 mmol) in dry N,N-dimethylformamide (DMF, ca. 120 mL), sodium
hydride (5.41 g, 225 mmol) was added portionwise at 0 °C under a nitrogen atmosphere. The mixture was stirred for 15 min at the same temperature, and then (1R,2S,5R)-2-isopropyl-5-methylcyclohexyl-p-toluenesulfonate (1a) (20.0 g, 64.4 mmol) was added in one portion to the reaction mixture under an inert atmosphere. The reaction mixture was warmed to room temperature and then heated to reflux for 24 h, after which it was poured into cold water (ca. 300 mL). The crude product was extracted with ethyl acetate (ca. 3 200 mL). The organic layers were collected and repeatedly washed with water (ca. 5 50 mL) followed by a saturated sodium chloride solution (ca. 50 mL). The organic extract was finally dried
with anhydrous MgSO4 and filtered, and the volatiles were removed in vacuo. The crude product was purified by column chromatography (silica, petroleum ether/EtOAc 95:5–20:80) to give the product
(1b) as a white solid (3.83 g, 29%).

I think, that in first step I'll separate a precipitate (eg. unreacted K2CO3) from organic layer. Next I'll make all what was described in article.

What do you think?
Ph.D student of organic chemistry from Poland
Speciality: Ionic Liquids, Chiral Ionic Liquids, Diels-Alder reaction

Offline orgopete

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Re: Conversion cyclic alcohols to tetriary amines
« Reply #18 on: November 21, 2016, 07:17:16 PM »
Today I made this reaction using K2CO3 in DMF, but i used pyrrolidine instead imidazole like was descriped in article: Eur. J. Inorg. Chem. 2015, 1604-1615.

What do you think?

Look at examples 17, 18, and 19 in the reference posted by AWK!
Author of a multi-tiered example based workbook for learning organic chemistry mechanisms.

Offline Nekromantis

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Re: Conversion cyclic alcohols to tetriary amines
« Reply #19 on: November 28, 2016, 08:21:02 AM »
I made this reaction. After extraction I made GC-MS analysis. I have 4 peaks
1. 4-Methyl-1-(1-methylethyl)cyclohexene,
2. Menthol
3. Product
4. Like a double menthol

Amount of product is small about 20%. Very much is menthol. Maybe my product decomposed in feeder, so I have peak 1 and 2, or I will should reaction parameters. I wonder why I have menthol? I used pure Ment-O-pTOS.
Ph.D student of organic chemistry from Poland
Speciality: Ionic Liquids, Chiral Ionic Liquids, Diels-Alder reaction

Offline rolnor

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Re: Conversion cyclic alcohols to tetriary amines
« Reply #20 on: November 28, 2016, 09:28:38 AM »
Isnt reductive amination done with sodiumcyanoborohydride? I have done a lot of these reactions, works well. For alkylating the triflate is a good leavinggroup but the triflat anhydride is maby not so cheap. I have also used bromide as leavinggroup, you can add some sodium iodide also as catalyst.

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