Thank you for your valuable answer. We don't have scifinder access that’s why I am looking for procedure in research gate.

There you can find the Synthesis:

M. Sortino et al./Bioorg. Med. Chem. 19 (2011) 2823–2834

Bilash,

Ethylamine hydrochloride (0.30 moles) is added to a solution of acetic acid (40 ml), maleic anhydride (0.20 moles) and potassium acetate (0.30 moles) and the mixture is stirred for 4-6 hrs at reflux temperature (100-120 oC). The reaction mix. is allowed to cool to room temperature then poured onto cold solution sodium bicarbonate solution (100 ml). The product is extracted with diethylether (3 x 40 ml). The organic layer is washed with water, dried over anhydrous sodium sulfate anhydrous. Remove the solvent in vacuum to afford your N-ethylmaleimide.

Good luck

if you start from maleic anhydride, let it react with your amine, which I expect to be pretty straightforward given the high reactivity of anhydrides....then you could perform the subsequent condensation by making a chloride on the free COOH or with PyBOP (which would require harsher conditions, in dint of the low reactivity of secondary amides)....

Thanks to all for providing valuable suggestions.

Nirogi et al. Bioorganic and Medicinal Chemistry Letters, 2011 , vol. 21, # 15 p. 4577 - 4580

There is described procedure for methylamine hydrochloride reaction with maleic anhydride, but you can follow it using ethyalmine hydrochloride as well. You should have access to the supplementary data for this paper:

Supplementary data associated with this article can be found, in

the online version, at doi:10.1016/j.bmcl

Thanks a lot Dr. Krzysztof for your information, I have downloaded the procedure. This will be very useful for me.