I used more amount of solvent to make more quick reaction and to not get such such big temperature, it can be used with different proportions but I think minimum is 350-400 ml.
The method was only in the case when the aq40% is not aviable or for some reason it not result good synthesis. Method is not scalable very much, it will rinse a lot of problems when scaled up but its ok for this scale.
If somebody recieve smaller yield there can be a lot of reasons, based on the purity of regents used, the techniques performed.
The 2i4m probably could be used but I did not test it.
If you do have bad yield or your reactoin turns out not clean - please do remember that using methylamine hcl rather than aq results more impurities, as well the alcohol with metylamine. The reaction must be performed ASAP with no futher delays until acidificatoin. Longer it takes worse result will be.
Regards.
The method was only in the case when the aq40% is not aviable or for some reason it not result good synthesis. Method is not scalable very much, it will rinse a lot of problems when scaled up but its ok for this scale.
If somebody recieve smaller yield there can be a lot of reasons, based on the purity of regents used, the techniques performed.
The 2i4m probably could be used but I did not test it.
If you do have bad yield or your reactoin turns out not clean - please do remember that using methylamine hcl rather than aq results more impurities, as well the alcohol with metylamine. The reaction must be performed ASAP with no futher delays until acidificatoin. Longer it takes worse result will be.
Regards.
I replaced the aqueous solution with hydrochloride because the smell is unbearable and everything smells of this chemical. Why do you think the synthesis isn't scalable? I've processed up to 5 kg of the precursor using your method and always had a yield between 55-60%. Aside from the fact that you do a bit of extra filtering, this route is very convenient in terms of handling.
What I've noticed is that the longer the free base is left unacidified, the darker the color becomes. The free base starts off a beautiful yellow with a certain color density, then changes to green or dark green. However, this problem can be easily managed with a few optimizations in the workflow.