Reduction of Nitroalkenes to the corresponding Nitroalkanes is carried out by directly combining the Nitroalkene with a 1.1 molar equivalent of Hantzsch ester, Diethyl 1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylate,CAS 1149-23-1, at 100°C and letting the two react for 12 hours. Yield: 84%

What confuses me: The Hantzsch ester schould be a solid at this temperature, so basically they form a suspension of it in molten nitroalkene?

From what I read about the Hantzsch compound, making it yourself should not be too complicated, refluxing ethylacetoacetate, formaldehyde and ammonium acetate in water for 2 hrs, then adding FeCl3 and reflux 1hr more.

But supplier prices for it are quite high, so there will certainly be a twist with this method somewhere.

Thoughts about this anyone?

Is there an efficient method of recycling the oxidized Hantzsch ester?

I didn´t find anything regarding that up until now.

But it seems that the compund is way cheaper than I thought, I will post experimental details in about a month or two.

...i've always thought the AlHg is the easiest and inexpensive way to the reduction....


http://www.erowid.org/archive/rhodium/chemistry/nitrostyrene.reduction.alhg.html


...of course there is the

Synthesis of Alkylamines via Reduction of Nitroalkenes
using in situ Prepared BH3·THF

http://www.erowid.org/archive/rhodium/chemistry/nitroalkenes2amines.bf3-nabh4.html


and the other interesting read from a SM thread....

http://www.sciencemadness.org/talk/viewthread.php?tid=7190


.......but without derailing the topic some comments found here ,

http://www.erowid.org/archive/rhodium/chemistry/nitroalkene.synthesis-reduction.review.html


Transfer hydrogenation with Hantzsch esters and related organic hydride donors
Chao Zheng and Shu-Li You
Chem. Soc. Rev.
2012, 41, 2498–2518
DOI: 10.1039/c1cs15268h