SYNTHESIS OF 4-TERT-BUTYL-3-(2-CHLORO-[-2-C-14]ETHYL)UREIDO BENZENE

Carbonation of CH3MgI with (CO2)-C-14 led to sodium [1-C-14] acetate: (1) under bar which was successively brominated and esterifed with dia zomethane to give rise to methyl 2-bromo-[-1-C-14] acetate: (3) under bar, the reduction of which with H3Al gave 2-bromo-[-1-C-14] ethanol ( 4) under bar. (4) under bar was then reacted with NaCN; the intermedia te 3-hydroxy-[-3-C-14] propionitrile (5) under bar was hydrolyzed with HCL at 130 degrees C into the corresponding acid: (6) under bar which was transformed into 3-chloro-[-3-C-14] propionyl chloride: (7) under bar;(7) under bar reacted with NaN3 gave 3-chloro-[-3-C-14] propyl az ide: (8) under bar which by Curtius rearrangment led to 2-chloro-[-2-C -14] ethyl isocyanate: (9) under bar which finally was condensed with 4-t-butylaniline leading to the title compound (radiochemical purity 9 9%) in an overall yield of about 10% based on [C-14] barium carbonate.