Sciencemadness Discussion Board

hydantoin alkylation?

stygian - 25-4-2006 at 21:20

Assume one has some 5-methylhydantoin.

Can this be alkylated at the 5 carbon with alkyl chloride + base? If not, how would one go about doing this.

Also, how would the two nitrogens be affected?

Sandmeyer - 26-4-2006 at 12:55

Sorry, I'm unable to give any refs. to the litterature at the moment. I can imagine that a possibility is to tosylate (mesylate) the both nitrogens, then use a base such as NaH to deprotonate the tert. carbon, treatment with alkylhalide (in DMF/NMP/DME), followed by desulfonation will give the desired compound. Hope it's at least of some help :(.

[Edited on 26-4-2006 by Sandmeyer]

stygian - 26-4-2006 at 16:23

Interesting thanks. But Another idea has struck me.

Anybody want to speculate on the reaction of 5-benzylhydantoin with diazomethane? From what I've been able to figure out it could methylate the N's or the carbonyls to ethers pulling H's off the N's. Could it, at least eventually, methylate at 5-C?

5-benzyl-5-methylimidazolidine-2,4-dione

Sandmeyer - 27-4-2006 at 15:00

Quote:
Anybody want to speculate on the reaction of 5-benzylhydantoin with diazomethane?


Reason I proposed what I did in my above post is that I thought you only had 5-methylhydantoin at your disposal. Now, I'm not sure. Anyways, any electrophilic attack will take place on the nitrogens first, hence the need of a protecting group. If I have understood your last post correctly you want to make 5-benzyl-5-methylimidazolidine-2,4-dione, urea and a-mephenylalanine give title compound.

Anteunis, M.J.O.; Spiessens, L.; Witte, M. De; Callens, R.; Reyniers, Fr.; Bull. Soc. Chim. Belg.; 96; 6; 1987; 459-466.

yield is 95% (I'm not sure what the amino acid costs though... probably expensive) :(

But, it is accesible via Strecker method: http://rapidshare.de/files/19096862/RESEARCHES_ON_HYDANTOINS...


RESEARCHES ON HYDANTOINS. L.1 THE SYNTHESIS OF HYDANTOINS POSSESSING THE PROPERTIES OF HYPNOTICS
Robert M. Herbst, Treat B. Johnson
J. Am. Chem. Soc.; 1932; 54(6); 2463-2470.

[Edited on 28-4-2006 by Sandmeyer]

stygian - 27-4-2006 at 20:06

My target was the benzylmethylhydantoin, via strecker or bucherer, hoping to find a way to a-Me-Phenylalanine (as a precursor ;)) from something besides phenylalanine, but it seems the known imine/ester protecting then alkylating of phenylalanine may be the best way in terms of work involved. I do look forward to reading this article though, thanks.


[Edited on 28-4-2006 by stygian]