The ¹⁴C, ¹³C and ¹⁵N syntheses of MON 37500, a sulfonylurea wheat herbicide

Abstract

Abstract [ 14 C] and [ 13 C]MON 37500 labeled in the imidazopyridine (Im) ring system were synthesized in seven steps in an overall yield of 39 and 28%, respectively, from [2‐ 14 C] and [2‐ 13 C]chloroacetic acid. [ 14 C]MON 37500 labeled in the pyrimidine (Pd) ring system was synthesized from [2‐ 14 C]diethyl malonate in four steps in 48% yield. Lastly, [ 15 N]MON 37500 was prepared in three steps in an overall yield of 28% from [ 15 N]ammonium chloride. Copyright © 2005 John Wiley & Sons, Ltd.