Amphetamine hydrochloride is like meth HCl a smokeable salt with mp 152-154°C. The effects of amphetamine are preferred to those of methamphetamine but swim likes to smoke.
The amphetamine was made via P2NP, Al/Hg reduction, extracted by a steam distillation and turned into the sulfate simply by neutralization and evaporation. For some experiments (analysis) the amphetamine base was dry-distilled from a sulfate/caustic mixture. When isolated base is wanted, a little solvent and a drying agent are added to the destillate and it is left to dry for 12 hours, then filtered and the solvent distilled off through a column. With isolated base some "in-situ" hydrochloride can be made by pipetting some freebase into the glass-pipe (made from a light-bulb, japanese-style), neutralizing with hydrochloric acid (36%) and heating until the water is gone and the so formed hydrochloride melts. Perfectly smokeable, this is what works most of the time.
However as the only satisfying goal the (dry) hydrochloride is to be isolated. Problem seems that it is said to be very hygroscopic and also the mp (152°C) is kinda low and can be even lower when impurities are present. Therefore it has been figured to give it a shot at anyhydrous gassing:
Some of the freebase is dissolved in toluene/xylene and its dryness asserted by boiling the solution for a moment. The gassing setup generates HCl from H2SO4 and NaCl and leads it through a H2SO4 bubbler, a CaCl drier and finally into a gas dispersion tube which is immersed into the solution. This worked once and gave hydrochloride crystals which could be filtered over a buchner. They were indeed found to be vastly hygroscopic, on the first attempt they drew water from the air and they were sucked through the buchner within a minute. Another attempt succeded when the buchner was covered with plastic wrap which vacuumized and compressed the filtercake. The cake was then further dried to absolute dryness in a desiccator. However, numerous attempts at gassing already failed at the gassing stage. At the beginning of the gassing process a precitipate is visible for a brief moment, but then the solvent/base mixture seems to absorb more HCl than necesary to give the salt, resulting in a fuming acidic solution which gets a red tint more often than not. At this point it was never possible to get it to precitipate back, not by freezing and not by evaporation. Evaporation in this case seems to yield decomposition products. Sometimes they have a ketonic smell to them, a slight hint of benzaldehyde and clearly there is something which seems to boil higher than even the xylen (hydrochloride melts at 152°C, so when we're boiling off something with a bp > 152°C the salt is in the melt). Therefore I recognized the gassing procedure as too unreliable. The only clue why this failed numerous times is that the HCl gas wasn't yet dry enough which could yield a "super-acid" (w/w conc. > 37%) which hydrolises the amphetamine and yields decomposition (or chlorinated) products which could have further absorbed HCl and/or irreversibly dissolved the hydrochloride salt.
For making hydrochlorides of primary amines in general there exist other procedures. Often cited is a procedure in which the amine is simply neutralized in alcoholic solution and then precitipated by the addition of ether. This has been tried in the same manner as it worked for methylamine once: freebase amine added to (dry) 2-propanol, titrated with fuming (37%) hydrochloric acid and precitipated with dry diethyl ether. When tried with amphetamine this simply didn't work.
Now at this point in the quest for amphetamine HCl a specifically designed procedure seems necessary. To come up with such methods and to ensure the effect of every step knowing the physical properties and the behaviour of this particular hydrochloride salt were required, however there seems to be lack of this information on the internet except for the melting point and there seems to be no writeup to isolate the hydrochloride as of this time. Going through printed literature finally a writeup was found where they make amphetamine by a LiAlH4 reduction and then they first make the picrate (from picric acid) and subsequently turn that into the hydrochoride. This has been found in "Psychedelische Chemie" by Daniel Trachsel and Nicolas Richard and translates as follows:
A solution of 9.8.g (60mmol) 1-phenyl-2-nitroprop-1-ene in 150ml dry diethyl ether is added to a gently boiling suspension of 8g LiAlH4 in 350ml dry diethyl ether by dropping through an addition funnel over the course of 2 hours. Then it is refluxed another 2 hours. It is cooled down and the excess hydride is destroyed carefully with 150ml sulfuric acid. The aqueous phase is separated and brought to pH 6 with litium carbonate, heated until boiling and filtrated (diatomaceous earth). The still hot filtrate is treated with a conc. ethanolic solution of 13.7g picric acid and left in the fridge over night. The precitipated crystals are filtered, rinsed with ether and dried. This yields 19.5 amphetamine picrate, mp 143-145°C. To get the hydrochloride salt, the picrate is treated with 6M HCl, the liberated picric acid extracted with benzene and the solution evaporated. The residue is recrystallized from ethyl acetate. This yields 7.0g (46mmol, 77%) amphetamine hydrochloride with a mp of 152-154°C.
Unfortunately it is not mentioned in this citation what the idea behind going through the picrate is. Also, it hasn't been tried so far because the acquisition and handling of picric acid is discouraged because it is an explosive.
Once it has been isolated some solubility properties would be determined and posted here, which could eventually lead to another method. Until then suggestions, ideas and pointers by fellow bees would be greatly appreciated!
The amphetamine was made via P2NP, Al/Hg reduction, extracted by a steam distillation and turned into the sulfate simply by neutralization and evaporation. For some experiments (analysis) the amphetamine base was dry-distilled from a sulfate/caustic mixture. When isolated base is wanted, a little solvent and a drying agent are added to the destillate and it is left to dry for 12 hours, then filtered and the solvent distilled off through a column. With isolated base some "in-situ" hydrochloride can be made by pipetting some freebase into the glass-pipe (made from a light-bulb, japanese-style), neutralizing with hydrochloric acid (36%) and heating until the water is gone and the so formed hydrochloride melts. Perfectly smokeable, this is what works most of the time.
However as the only satisfying goal the (dry) hydrochloride is to be isolated. Problem seems that it is said to be very hygroscopic and also the mp (152°C) is kinda low and can be even lower when impurities are present. Therefore it has been figured to give it a shot at anyhydrous gassing:
Some of the freebase is dissolved in toluene/xylene and its dryness asserted by boiling the solution for a moment. The gassing setup generates HCl from H2SO4 and NaCl and leads it through a H2SO4 bubbler, a CaCl drier and finally into a gas dispersion tube which is immersed into the solution. This worked once and gave hydrochloride crystals which could be filtered over a buchner. They were indeed found to be vastly hygroscopic, on the first attempt they drew water from the air and they were sucked through the buchner within a minute. Another attempt succeded when the buchner was covered with plastic wrap which vacuumized and compressed the filtercake. The cake was then further dried to absolute dryness in a desiccator. However, numerous attempts at gassing already failed at the gassing stage. At the beginning of the gassing process a precitipate is visible for a brief moment, but then the solvent/base mixture seems to absorb more HCl than necesary to give the salt, resulting in a fuming acidic solution which gets a red tint more often than not. At this point it was never possible to get it to precitipate back, not by freezing and not by evaporation. Evaporation in this case seems to yield decomposition products. Sometimes they have a ketonic smell to them, a slight hint of benzaldehyde and clearly there is something which seems to boil higher than even the xylen (hydrochloride melts at 152°C, so when we're boiling off something with a bp > 152°C the salt is in the melt). Therefore I recognized the gassing procedure as too unreliable. The only clue why this failed numerous times is that the HCl gas wasn't yet dry enough which could yield a "super-acid" (w/w conc. > 37%) which hydrolises the amphetamine and yields decomposition (or chlorinated) products which could have further absorbed HCl and/or irreversibly dissolved the hydrochloride salt.
For making hydrochlorides of primary amines in general there exist other procedures. Often cited is a procedure in which the amine is simply neutralized in alcoholic solution and then precitipated by the addition of ether. This has been tried in the same manner as it worked for methylamine once: freebase amine added to (dry) 2-propanol, titrated with fuming (37%) hydrochloric acid and precitipated with dry diethyl ether. When tried with amphetamine this simply didn't work.
Now at this point in the quest for amphetamine HCl a specifically designed procedure seems necessary. To come up with such methods and to ensure the effect of every step knowing the physical properties and the behaviour of this particular hydrochloride salt were required, however there seems to be lack of this information on the internet except for the melting point and there seems to be no writeup to isolate the hydrochloride as of this time. Going through printed literature finally a writeup was found where they make amphetamine by a LiAlH4 reduction and then they first make the picrate (from picric acid) and subsequently turn that into the hydrochoride. This has been found in "Psychedelische Chemie" by Daniel Trachsel and Nicolas Richard and translates as follows:
A solution of 9.8.g (60mmol) 1-phenyl-2-nitroprop-1-ene in 150ml dry diethyl ether is added to a gently boiling suspension of 8g LiAlH4 in 350ml dry diethyl ether by dropping through an addition funnel over the course of 2 hours. Then it is refluxed another 2 hours. It is cooled down and the excess hydride is destroyed carefully with 150ml sulfuric acid. The aqueous phase is separated and brought to pH 6 with litium carbonate, heated until boiling and filtrated (diatomaceous earth). The still hot filtrate is treated with a conc. ethanolic solution of 13.7g picric acid and left in the fridge over night. The precitipated crystals are filtered, rinsed with ether and dried. This yields 19.5 amphetamine picrate, mp 143-145°C. To get the hydrochloride salt, the picrate is treated with 6M HCl, the liberated picric acid extracted with benzene and the solution evaporated. The residue is recrystallized from ethyl acetate. This yields 7.0g (46mmol, 77%) amphetamine hydrochloride with a mp of 152-154°C.
Unfortunately it is not mentioned in this citation what the idea behind going through the picrate is. Also, it hasn't been tried so far because the acquisition and handling of picric acid is discouraged because it is an explosive.
Once it has been isolated some solubility properties would be determined and posted here, which could eventually lead to another method. Until then suggestions, ideas and pointers by fellow bees would be greatly appreciated!