dlktdr - 28-3-2010 at 22:57
I want to try HCl, HBr, HI gassing something to produce a salt of an organic molecule. (I'm not a fan of jail time so NOT a scheduled substance! or
precursor there of)
I would like to try converting say a organic, OTC pharmaceutical drug from it's HCl salt to it's HBr salt.. or vice versa.. Any suggestions.? Maybe
like Benadryl -Diphenhydramine... Something where extraction wouldn't be too difficult, and not costly. Most products always contain multiple
chemicals and binders.
Figured someone might have an idea...
Nicodem - 29-3-2010 at 01:32
Chemists rarely use HCl gas to make amine hydrochlorides. Maybe you got the wrong impression by reading drug cook recipes instead of procedures
described in the literature. Most commonly a solution of HCl in diethyl ether or alcohols is used, or conc. aqueous HCl.
If you want to use diphenhydramine as the model substrate, then you first need to check the literature if its hydrochloride is a crystalline solid at
all - some amine hydrochlorides do not crystallize and some are terribly hygroscopic. In this case we already know it is crystalline, because
diphenhydramine is used in the form of hydrochloride. Then you need to find out if the hydrochloride is soluble in water. If it is soluble in water
then you will have to precipitate it from diethyl ether or use a rotavapor to dry an neutralized aqueous solution. You also need to keep in mind that
diphenhydramine is an alkyl benzhydryl ether and thus unstable in highly acidic media - therefore you must take care not to add excess HCl. Then, when
you are done, check the patents on how it is really made and see if it is any simpler than what you did.
How about first using something more simple as a testing substrate. Some cheap ubiquitous amine like benzylamine or triethylamine perhaps?