[barcrphd]

i am trying N-alkylation of phthlimide protected diethylene triamine (both the primary amine groups are protected) with 1-bromo-2-chloro-ethane. i have tried different ways of doing it.
1) refluxing in acetonitrile using potassium carbonate
2) refluxing in DMF using N-ethyl-diisopropyl amine
3) refluxing in acetonitrile using N-ethyl-diisopropyl amine etc

but all these reactions are followed by TLC in ethyl acetate. but product formation is very very less.

is there any alternate way to do this reaction?

thanks a lot in anticipation

[movies]

How about deprotonating your amine with NaH and then add your electrophile?

[barcrphd]

i will try using NaH, but i have come across a reference where is saw NaH reducing the C=O bond. i cannot allow the amide bond to reduce, because, the second step of my reaction needs both the primary amine groups to be freed/

thanks for your suggestion

[movies]

Are you sure?  I have never seen an instance of NaH acting as a hydride reducing agent.  I have used NaH many times in the presence of ketones, which are generally much easier to reduce than an amide type carbonyl group.  I've never seen any reduction products with NaH!

I would love to see the reference you mentioned, I would find it very interesting.

[barcrphd]

dear movies,
i will get it for you. but i would like to tell one experience that i had with NaH. i was trying to synthesis the xanthate derivative of 16-hydroxyhexadecanoic acid. it can be synthesized by simple reaction with CS2 in presence of NaOH in ether. but the yield was very less. so we thought to use NaH. but then we cannot use the fatty acid as such. so we parepared the ethyl ester and carried out the reaction using NaH. when we took the IR of the product, we are shocked to see the ester peak missing. we did the reaction twice to confirm this. subsequently we looked some literature and found that, reduction of C=O is a possibility.
ofcourse, we didnt do any further investigation over this issue bcos our interest was something else. i will get back to you.