An improved one-pot procedure for the preparation of [C-11-carbonyl]-WAY100635

A simple one pot procedure for the preparation of [C-11-carbonyl]-WAY100635 , a potent 5HT1A receptor antagonist, was developed. The procedure involves the trapping of (CO2)-C-11 in a tetrahydrofuran (THF) solution of cyclohex ylmagnesium chloride, elimination of excess Grignard reagents with anhydrou s HCl, reaction with SOCl2, and the reaction of the resulting acid chloride with WAY100634 (2 mg) and triethylamine (20 mu L) in THF. The total synthe sis time is 45 min. Starting from 1326 +/- 173 mCi of (CO2)-C-11, the avera ge amount of [C-11-carbonyl]-WAY100635 (n = 40) at end of synthesis (EOS) w as 30 +/- 13 mCi (2.3% radiochemical yield), or 148 +/- 61 mCi (11%) at end -of-bombardment (EOB). The radiochemical purity was >99%, and the specific activity was 3.6 +/- 1.9 Ci/mu mol (EOS, n = 40), or 21.3 +/- 9.8 Ci/mu mol at EOB. This method is reliable and flexible for routine clinical studies. NUCL MED BIOL 26;7: 815-819, 1999. (C) 1999 Elsevier Science Inc. All righ ts reserved.