topramezone
topramezone
An aromatic ketone that is phenyl 1<em>H</em>-pyrazol-4-yl ketone in which the pyrazolyl group is substituted at positions 1 and 5 by methyl and hydroxy groups, respectively, and in which the phenyl group is substituted at positions 2, 3, and 4 by methyl, 4,5-dihydro-1,2-oxazol-3-yl, and methylsulfonyl groups, respectively. A potent inhibitor of 4-hydroxyphenylpyruvate dioxygenase (HPPD) that is rapily metabolised by corn to non-active substances, it is used as a herbicide for the treatment of broadleaf weeds.