[Labrat]

After nitration of toluene with nitric acid the 2 main components left in solution are orto nitrotoluene and para nitrotoluene. How can i separate them?

[macman104]

After nitration of toluene with nitric acid the 2 main components left in solution are orto nitrotoluene and para nitrotoluene. How can i separate them?

Short story is that it's a b***** to separate.  We nitrate (3-phenyl)propylbromide, and get ortho and para products.  It is a very long, frustrating column to separate them.  We run the column through pure hexane until the ortho product comes off, and then we can take the para product, however, it is a very long column to do this.  If you have a small amount, and access to HPLC, you may have better luck, but if you need to separate more than a small amount...

Another option is derivatize the compound in hopes of something down the line that will be more easy to separate the ortho and para mixtures.

[lutesium]

No its not that hard! A simple steam distillation will seperate the two substances. If you ask me how to do it:

Put some dH2O (distilled water) in the flask of the Nitro-Toluenes and start heating in a distillation apparatus collect the product in a beaker with some ice cold water. As the solution boils steam will carry o-Nitrotoluene with itself. When no more oil drops into the beaker stop distilling.


Lutesium...

[g-bones]

No its not that hard! A simple steam distillation will seperate the two substances. If you ask me how to do it:

Put some dH2O (distilled water) in the flask of the Nitro-Toluenes and start heating in a distillation apparatus collect the product in a beaker with some ice cold water. As the solution boils steam will carry o-Nitrotoluene with itself. When no more oil drops into the beaker stop distilling.


Lutesium...

are you sure that the physical properties of the two regioisomers will be that distinct to seperate them by a simple distillation?  basically will the boiling points be that much further away from each other?

[Borek]

Boiling points:

o - 220 deg C
m - 232.5 deg C
p - 238.5 deg C

[lutesium]

Or else you can do a fractional distillation from a vigroux column...  This is a much more guaranteed way than I've suggested earlier...


Lutesium...