ThreePointCircle
Bluelighter
- Joined
- Apr 21, 2016
- Messages
- 331
I posted this on the What is wrong... thread but it got buried. I hope making it into its own thread is ok.
I wanted to understand purification by recrystallisation a bit more - specifically when an impurity has similar solubility to the desired product.
I was reading for example here that an impurity of a similar solubility could be removed by recrystalisation if there was sufficient difference in concentrations - because their saturations are different and so one will recrystallise before the other. If you wanted to remove MDDMA HCL (for example), I note that its solubility appears to be the same as MDMA HCL, at least for the solvents listed. So could they be separated if the ratio was as high as 20:80? That article says the rule of thumb is 5 mol% or less but I was wondering if you could do it with repetitions and a tolerance for lower yield? Would the MDMA and MDDMA being closely related cause a problem?
Hopefully someone can answer, I couldn't find a lot of info online but I lack the chemistry knowledge so could have been googling the wrong thing.
I wanted to understand purification by recrystallisation a bit more - specifically when an impurity has similar solubility to the desired product.
I was reading for example here that an impurity of a similar solubility could be removed by recrystalisation if there was sufficient difference in concentrations - because their saturations are different and so one will recrystallise before the other. If you wanted to remove MDDMA HCL (for example), I note that its solubility appears to be the same as MDMA HCL, at least for the solvents listed. So could they be separated if the ratio was as high as 20:80? That article says the rule of thumb is 5 mol% or less but I was wondering if you could do it with repetitions and a tolerance for lower yield? Would the MDMA and MDDMA being closely related cause a problem?
Hopefully someone can answer, I couldn't find a lot of info online but I lack the chemistry knowledge so could have been googling the wrong thing.