Efficient synthesis of carbon‐14 labeled metabolites of the strobilurin fungicide mandestrobin using biomimetic iron‐porphyrin catalyzed oxidation

Abstract

Biomimetic oxidation using synthetic iron‐porphyrin (F20TPPFeCl) as a catalyst eliminated a xylene moiety of the fungicide mandestrobin, uniformly labeled with carbon‐14 at the benzyl ring, to produce the corresponding radiolabeled metabolite 1. This reaction mechanism was investigated by identifying chemical structures of intermediate 5 and p‐xyloquinone derivatives 6 and 7, as by‐products. Optimization of reaction factors based on the mechanism improved the yield of 1 from mandestrobin up to 87%. Finally, various carbon‐14 labeled metabolites of mandestrobin were prepared from 1.

Degradation of the strobilurin fungicide mandestrobin in illuminated water–sediment systems

“…Among them, 1 – 8 were prepared in our laboratory using previously reported methods. 12 , 21 , 22 ) 2,5-Dimethylphenol 9 was purchased from Sigma-Aldrich Japan (Tokyo, Japan). Pure water was supplied from a Direct-Q 3UV water purification system (>18 MΩ cm, Merck Japan, Tokyo, Japan).…”