Patent ID: 8193156

Claim:
A method of preparing γ-L-glutamyl-L-Selenomethionine comprising steps of: a) reacting glutamic acid with P-(1-chloro-1,3-dihydro-3-oxo-1-isobenzofuranyl)-phosphonic acid diethyl ester in aqueous sodium carbonate or potassium carbonate solution to form N-phthaloyl-L-glutamic acid; b) reacting N-phthaloyl-L-glutamic acid with acetic anhydride to produce N-phthaloyl-L-glutamic anhydride; c) reacting N-phthaloyl-L-glutamic anhydride with L-selenomethionine to produce γ-(N-phthaloyl-L-glutamyl)-L-selenomethionine; and d) deprotecting the product of step (c) by hydrazinolysis of the phthalimide group to yield γ-L-glutamyl-L-selenomethionine.