New and convergent synthesis of saflufenacil

Abstract A new, practical, and hundred‐gram scale synthesis of saflufenacil, a protoporphyrinogen oxidase (PPO) inhibitor herbicide, is described. The key intermediate N ‐methyl‐ N ‐isopropyl sulfamide ( 12 ) is obtained from sulfuryl chloride isocyanate, t ‐butanol, and N ‐methyl‐ N ‐isopropylamine in 74.8% yield over 3 steps. Saflufenacil is prepared in 48.6% yield over 8 steps and 98.7% purity (HPLC).