SpicyBrown (Hive Bee)
12-14-02 20:00
No 389569
      Nitroethane from... Nitromethane? Why not?  Bookmark   

Is there any reason why nitromethane couldn't be deprotonated at the carbon with a base, then treated with methyl iodide to yield nitroethane?

At first glance I'd think this could work- a simple alkylation, sort of... Although I've never seen mention of it.

SpicyBrown
 
 
 
 
    Rhodium
(Chief Bee)
12-14-02 23:16
No 389584
      Resonance forms  Bookmark   

If you deprotonate nitromethane, the negative charge will without doubt mostly reside on the oxygens rather than on the carbon atom as 1) oxygen is more electronegative than carbon and 2) there are two of them. Thus O-alkylation will predominate.

This is also the reason we cannot alkylate nitroethane with benzyl chloride to form phenyl-2-nitropropanes directly.

I think I have seen only one exception to this rule and that was the alkylation of 2-nitropropane with p-nitrobenzyl chloride, forming p-nitrophenyl-2-nitro-2-methylpropane, and the authors of the article somehow concluded that no other combinations worked. para-aminophentermine, anyone? wink
 
 
 
 
    SpicyBrown
(Hive Bee)
12-15-02 11:05
No 389706
      Oh yea...  Bookmark   

Oops! Didn't even think of that. Makes sense.... Thanks Rodhium.

SpicyBrown