Synthesis of the fungicide [14C]triadimefon

The synthesis of the fungicide [14C]triadimefon is described. Bromine transformed pinacolone into α ‐bromopinacolone; this reacted with 4‐chloro‐[U‐14C] phenol yielding 1‐(4‐chloro [U‐14C]phenoxy)‐3,3‐dimethyl‐2‐butanone; this was transformed by bromine into 1‐(4‐chloro[U‐14C]phenoxy)‐1‐bromo‐3,3‐dimethyl‐2‐butanone; this last compound reacted with 1,2,4‐triazole to yield [14C]triadimefon, i.e., 1‐(4‐chloro [U‐14C] phenoxy)‐3,3‐dimethyl‐1‐(1H‐1,2,4‐triazol‐1‐yl)‐2‐butanone. [14C]Triadimefon, having the specific activity 0.88 mCi/mmol, was obtained in 58% overall yield from 4‐chloro[U‐14C]‐phenol.