SWIM has tried various methods to make anhydrous MeNH2; the results are as follows:
40% aq. MeNH2 + solid NaOHSWIM could not get this to work with either NaOH or KOH, even with heating. I don't know why. Reagents were all lab grade. However, I understand this method should work.
Heating 40% aq. MeNH2By simply heating 40% aq. MeNH2 soln., the gas is pushed out of solution. However, quite a bit of the water will also come, so it is important to dry the gas by passing it through solid NaOH with this method.
aq. MeNH2.HCl + solid NaOHThis method worked well - make a concentrated solution of MeNH2.HCl in H2O by neutralising 40% aq. MeNH2 with aq. HCl, then boiling until you get a saturated solution. Then drip this onto solid NaOH, stirring occasionally. You will get lots of MeNH2 gas. When gas evolution stops, heat the flask gently, and it will start again.
solid MeNH2.HCl + solid NaOH + H2OThis method works the best; mix thoroughly equimolar amounts of MeNH2.HCl and NaOH. Then add a few drops of water. Lots of MeNH2 gas will bee produced. You won't need to add much more water, as water is produced by the reaction. However, if you just add a few drops at the beginning and do not use external cooling, all water will boil off and the reaction will stop again. At some stage, you will probably need to cool the rxn with an ice-bath to prevent it becoming too vigorous. Its all a question of how much water there is. When MeNH2 evolution has stopped altogether, heat it gently.
If totally anhydrous MeNH2 is required, pass the MeNH2 generated through these procedures through solid NaOH first.
Have fun, and remember if you play with MeNH2 gas, your clothes will stink of fish for days
. And don't smoke at the same time...
Sweet dreamz,
IudexK