Chemistry Synthesis of Caffeine from Theobromine

[Lachlan]

Homework Statement

Not specifically a homework question, but I need help about an idea I'm exploring for a depth study for school. I'm looking into synthesizing caffeine from theobromine, and my understanding of current procedures is that methyl iodide is a reagent (or dimethyl sulphate could be used instead) for the purpose of adding a methyl group to a Nitrogen on the theobromine molecule to turn it into caffeine. I have been told that I am not allowed to use either reagents due to safety factors, is there any other reagent that could be used or explored for the same purpose of adding a methyl group, that is safer?

Relevant Equations

N-Methylation of theobromine

Most of what I'm going off is from this article here - https://www.sciencedirect.com/science/article/pii/S0187893X15720926#bib0115. This presents methyl iodide as safer than dimethyl sulphate, which is true and helpful, but not safe enough for me to be able to use it at school. I understand its purpose in the reaction, as the N-Methylation is adding the methyl group, making it a caffeine molecule. What I'm asking is if this N-Methylation can happen with a safer reagent? If it can't then let me know too as then I'll look to pursue something else, but whatever you know helps.

 

[Mayhem]

Methylation properties (alkylation in general) is a huge hazard in chemical reagents. Good alkylation agents are typically dangerous as an intrinsic side-effect of their desired purpose.

From what I could find, dimethyl carbonate is a safe(r) alternative but also reported as weak, so yield might be questionable. You would also need basic conditions to deprotonate the imide. It's not clear that it would work at all btw.

 

[Lachlan]

Thank you very much, I will look into as much as I can.