Quote from: Tsjanga on September 24, 2012, 05:02:19 PM

Quote from: carl_nnabis on September 24, 2012, 04:29:27 PM

Well, tell your dog he should add some suited drying agent

Yeah he already told me that he would do it!
Can you tell me how much he would need to get 1 liter of xylene free of H2O, or is there some way to see it is free of H2O?

Xylene and water form a lower boiling point azeotrope:

h**p://en.wikipedia.org/wiki/Azeotrope

h**p://en.wikipedia.org/wiki/Azeotropic_distillation

You need to start learning about practical organic chemistry from textbooks instead of posting such questions:

http://library.sciencemadness.org/library/books/vogel_practical_ochem_3.pdf

http://library.sciencemadness.org/library/books/the_practical_methods_of_organic_chemistry.pdf

http://library.sciencemadness.org/library/books/practical_organic_chemistry.pdf

The end results from the effort applied 

quick questiong pertaining the bisulfite regeneration.

This procedure is copied from wd.

3. Stripping of the Sodium Bisulfite and recover pure Piperonal
- take all swiy's crystals of the former step and insert them in swiy's separatory funnel (yes in powder form)
- measure out 50ml water and add this to swiy's separatory funnel
- give swiy's separatory funnel a good shake
- add more portions of 10ml water and shake, until the product in swiy's separatory funnel is dissolved (it does not need to fish tank clear, just dissolved!)
- measure out 105ml water and put it on swiy's stirrer with a stirr bar
- weigh 10,5g Sodium Hydroxide (swiy knows, toilet destopper)
- add the Sodium Hydroxide to swiy's beaker with water on the stirrer, and start stirring for a few mins, it will warm up firmly
- let the solution cool back to room temp
- add the solution to swiy's separatory funnel, watch the solution in swiy's separatory funnel going from white to a bit more clear
- weigh 5g salt and add that to swiy's separatory funnel
- measure out 50ml ether, and add to swiy's separatory funnel
- shake with swiy's separatory funnel for a few mins, releasing the pressure in intervals
- take a good look in swiy's separatory funnel, mind the bubbles going from swiy's water to the top of the ether layer
- drain off the bottom (aqueous) layer, and discard
- pour the remaining layer in a (preferrably clear) glass dish
- let the ether evaporate (better outside, prevent headache)


Now, why the fudge is ether used to get the piperonal out? as far as i can tell piperonal dissolves in 500 parts water. There must be an easier way.

The piperonal should crash out it in the water, (if temperature allows it, piperonal mp)

Have been wasting atleast 200 ml of "compound".

Benzylidene-bis-dimethylamine
Benzaldehyde (106 g., 1 mole) was poured into a 1-liter flask containing 400 g. of 25% aqueous dimethylamine. The mixture was swirled occasionally during 10 minutes warming on the steam-cone. After cooling, the aqueous layer was saturated with potassium carbonate and the upper layer separated with the aid of 100 ml. of benzene. The benzene layer was dried over potassium carbonate, the benzene removed under reduced pressure and the residue distilled. The product was collected at 57-60°C/(0.9mmHg, 143 g. (80%).

N,N-Dimethylbenzamide
Benzylidene-bis-dimethylamine (44.5 g., 0.25 mole) was heated in a 200-ml. flask, fitted with a dropping funnel and reflux condenser with drying tube, in an oil-bath at 120-130°C. 2-Nitropropane (22.2 g., 0.25 mole) was added dropwise in the course of 2.5 hours with continuous evolution of dimethylamine. Heating was continued one additional hour and then the light amber reaction mixture was distilled. The forerun was collected at 35-70°C/20mmHg, and the dimethylbenzamide at 94-96°C/0.5mmHg, 35g (94%).