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Author Topic: Ambient Pressure Hydrogenation - Nitrile 2 Amine  (Read 114 times)

no1uno

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Ambient Pressure Hydrogenation - Nitrile 2 Amine
« on: September 24, 2009, 06:42:56 PM »
Here is the one from Synthetic Pages and it really ought to be of interest to those here, especially given the ease with which a benzaldehyde can be converted to a cinnamonitrile (see here), I've often wondered what would be the product with propionitrile (ie. would it be a-methylcinnamonitrile?), surely this hydrogenation would also take care of that double-bond...

Quote
Chemicals Used
3,4-Dimethoxyphenylacetonitrile (Aldrich, 98%) 10% Palladium on carbon (Aldrich) Solvents and conc. HCl
(Analytical Reagent Grade)

Procedure
3,4-Dimethoxyphenylacetonitrile (2 g, 11.3 mmol) was placed in a 1L single-neck round-bottomed flask
containing a magnetic stirrer bar and was dissolved in MeOH (225 mL). Concentrated HCl (9.4 mL) and 10%
Pd/C (1 g) were added and the flask was sealed with a new septum. The air was evacuated with a diaphragm
pump through the septum using a needle. A balloon of hydrogen replaced the diaphragm pump and the
evacuation process was repeated once more. The reaction was left to stir at room temperature for 2 hours.
The reaction mixture was filtered through a pad of celite® in a sintered funnel under a blanket of nitrogen;
CARE! DO NOT ALLOW Pd TO DRY OUT IN AIR. The celite was washed with MeOH (100 mL) and the
solvents were removed under reduced pressure. The resulting pale brown oil was suspended in DCM (50 mL)
and 2M NaOH (20 mL) added. The layers were separated and the organic layer washed washed with 2M
NaOH (20 mL). The combined aqueous layers were extracted with DCM (20 mL), dried (MgSO4) and the
solvent was removed under reduced pressure to yield the desired amine as an off-white solid (1.98 g, 97%)
which was very pure by NMR.
"...     "A little learning is a dang'rous thing;
    Drink deep, or taste not the Pierian spring:
    There shallow draughts intoxicate the brain,
    And drinking largely sobers us again.
..."

no1uno

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Re: Ambient Pressure Hydrogenation - Nitrostyrene to Amine
« Reply #1 on: October 09, 2009, 11:52:51 PM »
Quote
Typically, a mixture of B-nitrostyrene, 5% palladium on charcoal [K-type (see Experimental), 0.1 equiv] and 12M hydrochloric acid was stirred under hydrogen (1 atm) at 0'C for 3h.

They use ethanol as the solvent and a side-arm flask as the hydrogenator
"...     "A little learning is a dang'rous thing;
    Drink deep, or taste not the Pierian spring:
    There shallow draughts intoxicate the brain,
    And drinking largely sobers us again.
..."

Baba_McKensey

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Re: Ambient Pressure Hydrogenation - Nitrile 2 Amine
« Reply #2 on: October 10, 2009, 08:56:32 PM »
This is an interesting article.  Its about hydrogenation using colloidal Pd at ambient pressure using H2 stored in a burette with a separatory funnel water  reservoir.

THE HYDROGEN NUMBER OF SOME ESSENTIAL OILS AND ESSENTIAL OIL PRODUCTS. I. OILS OF SASSAFRAS, ANISE, FENNEL, CLOVE AND PIMENTA.
Alan R. Albright
J. Am. Chem. Soc., 1914, 36 (10), pp 2188–2202
Publication Date: October 1914 (Article)
DOI: 10.1021/ja02187a026
http://pubs.acs.org/doi/pdf/10.1021/ja02187a026
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