Author Topic: phenyl-2-nitropropane->1-oximino-P2P with NaNO2  (Read 1060 times)

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indole_amine

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phenyl-2-nitropropane->1-oximino-P2P with NaNO2
« on: November 01, 2004, 08:33:00 PM »
A novel oxidative reaction of 2-nitro-1-phenylpropane with sodium nitrite. A new approach to prepare 1-oximino-1-phenylacetones
Chongzhao Rana, Genjin Yangb, Taizhi Wua, Meihua Xiea
Tetrahedron Letters 44, 2003 (vol. 44), pp 8061 - 8062




Abstract
A useful method for preparation of 1-oximino-1-phenylacetones via a novel oxidative reaction of 2-nitro-1-phenylpropanes with sodium nitrite was reported.






This looks VERY interesting for synthing ephedrine derivatives IMO...


indole_amine

Kinetic

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Ephedrine derivatives
« Reply #1 on: November 01, 2004, 08:55:00 PM »
I don't agree that

This looks VERY interesting for synthing ephedrine derivatives

There are too many steps for this to be of use in synthesising ephedrine derivatives. You would have to:

1. Make the nitrostyrene from the benzaldehyde
2. Reduce the double bond to give the nitroalkane
3. Oxidise the nitroalkane to the 1-oximino-1-phenylacetone
4. Hydrolyse this to 1-phenyl-1,2-propanedione
5. Perform a selective reductive amination to give the methcathinone derivative (STAB as reducing agent may work; this is expensive but has been recommended in the past)
6. Reduce the benzylic carbonyl of the methcathinone derivative to the alcohol to finally give the ephedrine derivative.

If you are starting from a benzaldehyde and nitroethane, you are far better off making the nitroalcohol via a Henry condensation, followed by reduction to the aminoalcohol and N-methylation.

But if you have a better idea in mind, please post it.

You could also proceed from any propiophenone to give an ephedrine derivative in around 70% overall yield. The synthesis is incredibly easy, but then I am a little biased with regards that route. ;)