how much Methylamine per kg ketone? client insisting on 230g

[Gale]

I have a client insisting I make a batch for him using

230g methylamine
1kg mdp2p
.75 mercury

This is off. I just want to confirm with you before I respond to the client I cannot do 230g Methylamine HCl per kg ketone.

 

[Bennychairman]

can answer but where one would get mercury?

 

[MadHatter]

Easy access. You either buy mercury tilt switches on ebay or amazon, or you order it from Polish chemical companies. Mercury really isn't that hard to source.

 

[cokemuffin]

cinnabar is a good otc source too, gets sold as a pigment or as minerals.

 

[MadHatter]

And to answer the question: I think the molar ratio of P2P to methylamine is 1:1.
Molar mass of methylamine is 31 g
Molar mass of P2P is 134 g
1000 g of P2P = 7.46 mol
7.46 mol of methylamine = 7.46 * 31g = 231 g.

Your client has both a brain and a calculator. But it also depends on what form your methylamine comes in. Pure freebase? Solution in water? Hydrochloride salt? 230 g is for the pure molecule. Also, better to use a slight excess of methylamine.

 

[MadHatter]

Sorry, I missed that your ketone was MDP2P. It has a molar mass of 178 g. So a kg would amount to 5.62 mol. Which would mean 174 grams of methylamine.

But you also did write methylamine HCl, which has a molar mass of 67.5 g. So 5.62 mols of that would be 380 grams.

Right answer thus: 1000 g.s of MDP2P + 380 G:s of methylamine salt. Let's say 400 shall we? But before the reaction one should convert the salt to freebase, right?

 

[Gale]

Thank you for this, I did not do the calculations myself until after posting. I got a different number though and realized my methylamine mass was for the base.

My qeustion here should be can I get this efficiency with standard Al/hg using methylamine HCL at atmospheric pressure? I've based my synth off of other synths such as osmiums al/hg which apperently require more methylamine HCl.

 

[Gale]

I find it odd they did not include the amount of Al, I assume they are reffering to the boro reduction. The methods I've found online for the al/hg using methylamine HCl all use higher amounts of methylamine, inlc labtop boro reduction. I have a feeling I cant grt away with using 400g per kg Unless I go with pressurized vessels and/or other catalyst like platinum. I wish I had some sodium borohydride I love to try that out. I might have some STAB.

 

[MadHatter]

I guess most write-ups use an excess of methylamine. There's no point in using too little, since it will reduce yield. I'm not 100% sure the molar ratio is 1:1, but looking at the reaction methylamine is the nitrogen donor and there's one nitrogen being transferred for every molecule of mdp2p. So it should be 1:1. Most write-ups I read uses more or less a 1:1 ratio though.
This: https://www.erowid.org/archive/rhodium/chemistry/redamin.nabh4.html
Osmiums write-up calls for a molar ratio ketone:amine of 1:2. I don't really know why though.

But why would a boro reduction use Hg? I think the amalgamation of aluminum is implied. Which means making the mercury salt first.

 

[G.Patton]

Hi, It worth to take 1:2 excess (1:1.5 at least) by reason that methylamine is volatile very well and you'll loose part of MeNH3 during reaction. Moreover, it almost always recommended to take nucleophilic reagent during addition reaction in a little excess to improve the yield.

 

[sorena2316]

Hello, in my opinion, every 1000 grams of phenylacetone requires 1800 grams of methylamine hydrochloride. Of course, this is my technical experience after years of research and experience

 

[cokemuffin]

Molar ratios would be roughly 1000g p2p to 500g methylamine HCl, 1800g doesn't make sense at all. If that's really the result of your ''research and experience'' i'd suggest you do some syntheses that fit your chemistry skills more, acetone peroxide on a kilogram scale seems fitting imo.