Synthesis of ³H, ¹⁴C and ¹³C₆ labelled Sch 58235

Abstract

Summary3 H-Sch 58235 was prepared at a specific activity of 29.1 Ci/mmol by Ir(COD)(Cy 3 P)PyPF 6 catalysed exchange with tritium gas.14 C-Sch 58235 was prepared in three steps from p-hydroxy[ring-U-14 C]benzaldehyde with an overall radiochemical yield of 21%. 13 C 6 -Sch 58235 was similarly prepared in three steps from p-hydroxy[ring-U-13 C 6 ]benzaldehyde in an overall yield of 41%.

Preparation of Enantiomerically Pure Compounds Labeled with Isotopes of Hydrogen and Carbon

“…CBS reduction of 3 0 -bromo-and 3 0 -methoxy[carbonyl-14 C]acetophenones (33) with BH 3 ÁTHF in the presence of 0.3 equivalents of (S)-30b furnished (R)-carbinols 34 in chemical yields of 75% and e.e.s of 97%. 43 . Alcohol 39 was isolated after CBS reduction of ketone 38 with BH 3 ÁMe 2 S in the presence of 0.3 equivalents of (À)-30a in nearly quantitative yield and > 99% e.e.…”

“…Further reduction with LiAlH 4 converted 42 into (4R)-[1,4-14 C 2 ]ibutilide (43), an antiarrhythmic agent 44 . Further reduction with LiAlH 4 converted 42 into (4R)-[1,4-14 C 2 ]ibutilide (43), an antiarrhythmic agent 44 .…”

27 Radiochemistry

“…General methods for tritium labelling have been reviewed, 42 as have specific routes for the synthesis 43 of the isotopomers of -tyrosine. Catalytic tritiation of a double bond continues to be used as an effective way of both introducing a double tritium label at a known site in a molecule and of generating a radiopharmaceutical [44][45][46] with a very high specific activity. Catalytic exchange, either with tritium gas 44 or with tritiated water, to produce [ 3 H]-zaleplon 47 is also very effective.…”

Preparation of tritium‐labeled PF‐622, a novel fatty acid amide hydrolase inhibitor

“…Although tritium-labeled compounds can be prepared by multistep chemical synthesis, as are carbon-14-labeled compounds, a more ideal approach is to use the method of metal catalyzed hydrogen isotope exchange to introduce tritium into the final product. Several effective metal catalysts were developed for "fast" tritium labeling of drugs, such as H-T exchange [3][4][5][6][7][8][9] and tritiodehalogenation. [10][11][12][13] This paper details the specific radiosynthesis of 3 tritium isotopomers ( Figure 1) in the presence of commercially available catalysts.…”