The synthesis of [(3)H]SCH 466036, [Me-(3)H3]SCH 466036, [(13)C,(2)H3,(15)N]SCH 466036 and [(14)C]SCH 466036 is described. [(3)H]SCH 466036 was prepared in two steps via Raney Ni-catalysed exchange with tritiated water. [Me-(3)H3]SCH 466036 was prepared in a single step from [(3)H]methyl iodide in 45% yield. [(13)C,(2)H3,(15)N]SCH 466036 was prepared in two steps from [(15)N]hydroxylamine and [(13)C,(2)H3]methyl iodide with an overall yield of 16%. [(14)C]SCH 466036 was prepared in seven steps from [(14)C]potassium cyanide in an overall yield of 13%.

MK 3814 is a potent and selective antagonist of the A receptor. A receptor antagonists have the potential for the treatment of Parkinson disease. Three distinct isotopically labelled forms of MK 3814 were synthesized. [ H]MK 3814 was prepared for a preliminary absorption, distribution, metabolism, and excretion data (ADME) evaluation of the compound and [ C]MK 3814 for more definitive ADME work, including an absorption, metabolism, and excretion study in man. In addition, [ H ]MK 3814 was prepared as an internal standard for a liquid chromatography mass spectrometry bioanalytical method. This paper discusses the synthesis of 3 isotopically labelled forms of MK 3814.