Xicori (Hive Bee)
08-03-03 21:44
No 451468
      3-indolyl-beta-methyl-beta-methylethylene  Bookmark   

High Bees!

Swim tried today the Henry condensation of Indole-3-carbaldehyde with Nitroethane.

It was done as follows:

15g Indole-3-COH were placed into a 250ml RBF together with 15ml Nitroethane, 7g of Ammonium Acetate and 70ml of Glacial Acetic Acid. The Mixture was hold at reflux for ~ 2 hours. During this time 20ml of Acetic Anhydride were added.

The colour went from yellow over a dark red to a nearly black solution. After the mixture had cooled down it was poured onto 200ml of ice water. A solid formed, and it was buchnered. -> yellow/brown & amorph

This was recrystallized from ~200ml of 96% EtOH to form  brown/yellowish crystals (still drying, so no weight available). The mother liquour has a deep red colour...to this was added water and crystals foarmed again....

So now my question... is the solid that crystallized out of the EtOH my nitropropene? what should it look like?

many thanks,
(Hive Bee)
08-04-03 10:19
No 451569
      the brown/yellowish solid obtained from ...  Bookmark   

the brown/yellowish solid obtained from recrystallisation is now dry, it weights 8,7g.

...the melting points of the desired product and indole-3-carbaldehyde are very close together, so indetification is very difficult...

is there any test to confirm the identity of the nitropropene?
many thanks,
(Hive Adickt)
08-04-03 11:16
No 451576
      TLC  Bookmark   

1: Make an TLC !
(iff you dont have TLC plate's paperchromatography is also ok (coffefilters ect)
2: The aldehyde will give a nice yellow spot with 2,4-dinitrophenylhydrazin.
08-04-03 11:24
No 451577
      The nitropropene color should be yellow - as...  Bookmark   

The nitropropene color should be yellow - as always.
(Chief Bee)
08-04-03 13:07
No 451586
      Naah... In this case I'd say more towards the...  Bookmark   

Naah... In this case I'd say more towards the orange part of the spectrum...