Synthesis of MMDA from Parsley Leaf Oil

Synthesis of MMDA from Parsley Leaf Oil by Iudexk

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STEP 1 – Purification and extraction of myristicin from parsley leaf oil

Contexto

Obviously, the best way to do this would be by fractional vacuum distillation. But if you don’t have this, wash w/ an equal volume of 5% NaOH, followed by 3x w/ half the volume of dH2O. If you have a problem separating the layers, saturate w/ a little NaCl. Now dry your myristicin by heating @105C until all bubbling ceases.

STEP 2 – Iodination of myristicin

Okay. For this you will need to generate HI. You can do this by dripping dH2O onto RP/I2. You need an equimolar amount of HI to myristicin. FW of myristicin = 193.224. FW of HI = 127.912. So for every 10g myristicin, you’ll need 6.62g HI. Let’s call it 7g. The equation for producing hydrogen iodide from iodine and red phosphorus is

16 H2O + 10 I2 + P4 —> 20 HI + 4 H3PO4

so for every 7g HI you’ll need 6.94g I2, 0.17g RP and 0.79mL dH2O. So get a 50mL bottle, punch a hole in the lid and epoxy 2 tubes in place, one short one and one long one. In the short one, put an addition funnel containing dH2O. Epoxy the other end of the longer tube thru the cap and in to the bottom of a second 50mL bottle, filled w/CaCl2 to dry the HI. Another tube comes out of this bottle, going into the top of a third 50mL bottle, which accomadates for suckback. Out of this bottle comes another tube, out of which dry HI will come. Make sure everything is sealed FIRMLY w/ lots of duct tape. Keep the container with your myrsticin in in an ice/salt bath. Add 1mL dH2O, slowly and watch your myristicin iodinate. Or scale up.

STEP 3 – Purification of crude iodomyristicin

Unless you can ditil it under vacuum, take your just-iodinated myristicin, and wash w/: half the volume of 5% NaOH (2x), dH2O, then chill to 0C and wash w/ half the volume of cH2SO4, also chilled to 0C, then w/ 3x dH2O.

STEP 4 – Preparation of concentrated NH3 in MeOH

The idea here is to bubble NH3, made from NaOH and (NH4)2SO4 (ammonium sulphate fertilizer), into anhydrous MeOH, as cold as possible. So, the rxn to make the NH3 is: (NH4)2SO4 + 2NaOH -> 2NH3 + Na2SO4 + 2H2O. You want a 10x molar xcess of NH3 to myristicin, so to be on the safe side slowly drip 40g aq. NaOH onto 67g ammonium sulphate fertilizer. Use the same set up as for the HI generator, sept dry w/ NaOH instead. Bubble thru 35mL anhydr. MeOH in an ice/salt bath. Pre-chill the MeOH in a freezer to bout @-11C. This is for 10g myristicin. Obviously u can scale up for more.

STEP 5 – Amination

Now get another bottle, and mix the iodomyristicin and NH3 in MeOH together, screw the lid on *tight*, and wrap up with LOTS AND LOTS of duct tape. Store for 1 week and shake vigorously regularly. The higher the temp., the faster your rxn will go, but make sure your container can withstand the pressure and also unwanted side-rxns generally tend to occur more at higher temperatures.

Conclusión

I think it is important to point out that if iodination is not carried out slowly, or the distance from the end of the iodination tube is not sufficiently deep, it may be necessary to generate a large excess of HI. Completion of the rxn can be determined by weighing the supposedly iodinated myristicin to see if the weight has increased by the expected weight. Also, there appears to be a large variation in the constituents of parsley leaf oil, myristicin content varying from 2% to 90%, so knowing the constituents could be helpful. Other allylbenzenes present are predominantly apiole and TMAB. It also seems there is a difference in some cases between parsley herb and leaf oils.

IudexK