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Synthesis of [75Se]5-ethoxycarbonyl-4-methyl-1,2,3-selenadiazole
A R Jalilian1, P Rowshanfarzad, H Afarideh
1Cyclotron Department, Nuclear Research Center for Agriculture & Medicine, P.O. Box 31585-4395, Karaj, Iran. amirreza.jalilian@yale.edu
Abstract:
Selenium-75 (t1/2 = 120.4d; 100% EC) was prepared in no-carrier-added form by 22MeV proton-bombardment of natural arsenic(III) oxide powder held in a copper-aluminum drawer target (highest yield, 35 microCi/microAh; maximum current, 6 microA), followed by oxidation to [75Se]selenium(IV) oxide. No-carrier-added [75Se]5-ethoxycarbonyl-4-methyl-1,2,3-selenadiazole was prepared in one step from ethylacetoacetate semicarbazone with [75Se]selenium(IV) oxide in glacial acetic acid at 50 degrees C. Column chromatography of the final solution afforded the desired labeled compound in 30% yield and greater than 98% radiochemical purity.
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