What’s the most efficient procedure to the synthesis of 4-MMC? This is a question that appears quite frequently on this forum and with multiple ways of doing this synthesis it can be confusing for novices and amateurs or even more experienced clandestine chemists. We developed a procedure that should be quick, easy follow and should give high, consistent yields (providing that the quality of the involved chemicals is appropriate). Now this is a rather small scale example which we advise all beginners to work with until mastering it, scaling up to vessels manipulable by hand (10-20L) shouldn’t be hard to do as long you are well aquatinted with smaller batches (increasingly larger).
Required materials:
GLASSWARE/EQUIPMENT:
20.0g (0.087mol) of 4’M2BK where added to a 250ml flat bottom flask equipped with magnetic stirring.
15ml of NMP where added to the R.F. and stirring is turned on. (Fig.1)
30ml of DCM where also added to the R.F. right after. (Fig.2)
25ml of 40% a.q. monomethylamine freebase is added to the R.F. in one portion (fig.3), and a timer/stopwatch is turned on before a rubber stopper with a needle (so that pressure can escape) is added to the neck of the R.F. stirring intensity is increased and a timer it set to 30 minutes (25-40 depending on case and scale in general bigger batches need more time).
Over the course of 35 minutes the colour developed from the milky white(fig.4) to this strong yellow(fig.5). When the color stops intensifying in yellow (not orange) and exothermal phenomena subside the reaction is quenched with 60ml H2O added in one portion. (fig.6)
The R.M. is transferred into a sep funnel (fig.7)where it was washed another 2 times with 60 more mL distilled water and the pooled a.q. washes where then placed into a separate beaker (fig.8). The organic layer is drained into a separate beaker and dried over anhydrous MgSO4(fig.9). The washes where then extracted with 10-15mL dcm and the non polar DCM layer was placed in the same beaker with the organic layer (fig.10). The beaker with the DCM layers where dried for several minutes and placed into the fridge to cool (15-20 minutes).
*Dry acetone and conc. HCl a.q. are also advised to be freezer cold before proceeding.
The acid is added dropwise to the freebase in dcm mixture under fast stirring (fig.11) whilst also adding slowly increasing portions of acetone occasionally (fig.12) in the mean time… pH should also be monitored (don’t forget to moist the indicator) and should be fine around 6. Some where at 2/3 or 3/4 of the final mixture should be acetone in the end and it normally precipitates as a solid block that needs to be broken up with a glass rod (vid.1). This was vacuum filtered and washed twice with cold acetone.
Theoretical yield: 18,74g (4MMC HCl)
Practical yield 15.89g (85%) fig.13
Using this method our highest yield was 92%.
Note that we have used this procedure with varying degrees of success with other substituted methcathinones (3-chloro is a bitch to precipitate and also to recrystallise). Hope this was easy to follow and wish you the best luck!
P.M. Feel free to add your thoughts and results as well as problems you shouldn't but might encounter so we can help. The main reason for small batches is not to feel guilty for you being wasteful miss interpreting our writeup.
Required materials:
GLASSWARE/EQUIPMENT:
- Reaction flask 250mL (round, flat or Erlenmeyer)
- Magnetic stirrer (simple one will do)
- Beakers (One for drying, one for precipitating and one for depositing at least)
- Separatory funnel 250ml
- Vacuum filtration apparatus
- Graduated cylinder 1x100mL+1x10ml (or 25mL)
- Scale 0.01g accuracy
- Ph paper
- Pipettes 2ml (a couple)
- glass stirring rod
- 2-bromo-1-(4-methylphenyl)propan-1-one(4’M2BK)
- Dicloromethane (DCM)
- N-Methylpyrolidone(NMP)
- 40%aq. methylamine (M40)
- Distilled water (tap water may be also used)
- Acetone 200-400ml (cold)
- Conc.Hcl aq. @~37% 5-6ml (cold)
- Anhydrous magnesium sulfate(MgSO4)
20.0g (0.087mol) of 4’M2BK where added to a 250ml flat bottom flask equipped with magnetic stirring.
15ml of NMP where added to the R.F. and stirring is turned on. (Fig.1)
30ml of DCM where also added to the R.F. right after. (Fig.2)
25ml of 40% a.q. monomethylamine freebase is added to the R.F. in one portion (fig.3), and a timer/stopwatch is turned on before a rubber stopper with a needle (so that pressure can escape) is added to the neck of the R.F. stirring intensity is increased and a timer it set to 30 minutes (25-40 depending on case and scale in general bigger batches need more time).
Over the course of 35 minutes the colour developed from the milky white(fig.4) to this strong yellow(fig.5). When the color stops intensifying in yellow (not orange) and exothermal phenomena subside the reaction is quenched with 60ml H2O added in one portion. (fig.6)
The R.M. is transferred into a sep funnel (fig.7)where it was washed another 2 times with 60 more mL distilled water and the pooled a.q. washes where then placed into a separate beaker (fig.8). The organic layer is drained into a separate beaker and dried over anhydrous MgSO4(fig.9). The washes where then extracted with 10-15mL dcm and the non polar DCM layer was placed in the same beaker with the organic layer (fig.10). The beaker with the DCM layers where dried for several minutes and placed into the fridge to cool (15-20 minutes).
*Dry acetone and conc. HCl a.q. are also advised to be freezer cold before proceeding.
The acid is added dropwise to the freebase in dcm mixture under fast stirring (fig.11) whilst also adding slowly increasing portions of acetone occasionally (fig.12) in the mean time… pH should also be monitored (don’t forget to moist the indicator) and should be fine around 6. Some where at 2/3 or 3/4 of the final mixture should be acetone in the end and it normally precipitates as a solid block that needs to be broken up with a glass rod (vid.1). This was vacuum filtered and washed twice with cold acetone.
Theoretical yield: 18,74g (4MMC HCl)
Practical yield 15.89g (85%) fig.13
Using this method our highest yield was 92%.
Note that we have used this procedure with varying degrees of success with other substituted methcathinones (3-chloro is a bitch to precipitate and also to recrystallise). Hope this was easy to follow and wish you the best luck!
P.M. Feel free to add your thoughts and results as well as problems you shouldn't but might encounter so we can help. The main reason for small batches is not to feel guilty for you being wasteful miss interpreting our writeup.
