Furch
Hazard to Others
Posts: 130
Registered: 8-10-2006
Member Is Offline
Mood: No Mood
|
|
Prep. of EtNO2 using acetone as solv.
I wonder if the standard solvents for the preparation of nitroethane from ethyl bromide and NaNO2 can be swapped for other Sn2 facilitating solvents,
such as acetone. The reason is that acetone for most people is much cheaper and more readily available than DMSO and DMF and formamide.
Since the reaction in question takes place at room temperature, the low boiling point of acetone can hardly be a reason for it not to work.
I know acetone isn't AS good a Sn2 promoting solvent as DMF and DMSO and formamide, but perhaps it's worth the compromise?
What am I missing?
\"Those who say do not know, those who know do not say.\" -Lao Tzu
|
|
|
guy
National Hazard
Posts: 982
Registered: 14-4-2004
Location: California, USA
Member Is Offline
Mood: Catalytic!
|
|
The problem is that acetone doesn't dissolve ionic salts like NaNO2 well. DMF and DSMO are very polar and can dissolve those compounds.
|
|
|
Furch
Hazard to Others
Posts: 130
Registered: 8-10-2006
Member Is Offline
Mood: No Mood
|
|
Sure, my common sense tells me that as well... But I also understand that for instance NaI in acetone reacts readily with other alkylhalides... This
wouldn't be possible unless the I- dissolves to some extent in the acetone. So reasonably it should have some solvative effect on inorganic salts, no?
\"Those who say do not know, those who know do not say.\" -Lao Tzu
|
|
|
guy
National Hazard
Posts: 982
Registered: 14-4-2004
Location: California, USA
Member Is Offline
Mood: Catalytic!
|
|
Then I guess in the cases where it does dissolve and doesn't react with the acetone it should work.
|
|
|
jon
Hazard to Others
Posts: 459
Registered: 11-1-2006
Member Is Offline
Mood: paranoid distrustful apprehensive
|
|
yeah there was some procedure where hypothetically it was done in DMSO but ethyl bromide would make a sulfur ylide with dmso so we know that's
bullshit.
|
|
|
chemrox
International Hazard
Posts: 2961
Registered: 18-1-2007
Location: UTM
Member Is Offline
Mood: LaGrangian
|
|
Jon, if the ethyl bromide is distilled from DMSO the product will be acetaldehyde...there's a paper on this I shall find and send you or post if
requested.
|
|
|
Nicodem
Super Moderator
Posts: 4230
Registered: 28-12-2004
Member Is Offline
Mood: No Mood
|
|
| Quote: | Originally posted by Furch
Sure, my common sense tells me that as well... But I also understand that for instance NaI in acetone reacts readily with other alkylhalides... This
wouldn't be possible unless the I- dissolves to some extent in the acetone. So reasonably it should have some solvative effect on inorganic salts, no?
|
But NaNO2 (unlike NaI) is insoluble in acetone, at least as far as I know.
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
