Deprotection of ethylcarbamate (secondary amine protecting group)

[Fertile]

Looking at various on-line answers I find:

simple method ; you can unprotect the secundary amine with carbamate in acid medium or basic medium
1-added NaOH ( 1M) solution ( synthesis of molecule 1).
2-if you used HCl (1M) solution (synthesis of molecule 2).

But before you ask, molecule 1 and molecule 2 are not defined.

Other answers:

Carbamic acids are not stable so you can simply reflux in HCl conc. Progress of reaction can be controlled by CO2 evolution.Then distill off any volatile materials, and recrystallize rest of hydrochloride salt from alcohol.

Yield isn't given but for the related methyl carbamate, TMSI in CHCl3 reflux for 6 hours gives 100% yield of product.

Any better suggestions?

In my specific case, noroxycodone & noroxymorphone ethylcarbamate are both commercially available and so the first step is deprotection. But I cannot find a specific deprotection methodology for these compounds.

So if anyone has a textbook or a reference, I would be mighty greatful.

 

[Jabberwocky]

Looking at various on-line answers I find:

simple method ; you can unprotect the secundary amine with carbamate in acid medium or basic medium
1-added NaOH ( 1M) solution ( synthesis of molecule 1).
2-if you used HCl (1M) solution (synthesis of molecule 2).

But before you ask, molecule 1 and molecule 2 are not defined.

Other answers:

Carbamic acids are not stable so you can simply reflux in HCl conc. Progress of reaction can be controlled by CO2 evolution.Then distill off any volatile materials, and recrystallize rest of hydrochloride salt from alcohol.

Yield isn't given but for the related methyl carbamate, TMSI in CHCl3 reflux for 6 hours gives 100% yield of product.

Any better suggestions?

In my specific case, noroxycodone & noroxymorphone ethylcarbamate are both commercially available and so the first step is deprotection. But I cannot find a specific deprotection methodology for these compounds.

So if anyone has a textbook or a reference, I would be mighty greatful.

"Carbamates, typically used for the protection of amines, including Cbz, Alloc, and methyl carbamate, can be readily deprotected by treatment with 2-mercaptoethanol in the presence of potassium phosphate tribasic in N,N-dimethylacetamide at 75 °C. This nucleophilic deprotection protocol is superior to the standard hydrogenolysis or Lewis acid-mediated deprotection conditions for substrates bearing a functionality sensitive to these more traditional methods."

https://pubs.acs.org/doi/abs/10.1021/acs.orglett.2c01410

Seems like it's exactly what you want. A gentle deprotection process that won't damage the oxymorphone molecule.

Hope this is what you were looking for. I attached the actual link to the paper. I know you're a chemist.

 

[VerbalTruist]

Since it’s been answered, I’m going to lock this. Also, @Fertile don’t you think this breaks the synth discussion rule? If not PM me why.