Synthesis Of Metamitron

Metamitron, 4-amino-3-methyl-6-phenyl-l,2,4-triazin-5-one, a kind of herbicide was synthesized from phenylglyoxylic acid ester by three step reactions such as condensation, hydrazinolysis and cyclization. The yield is 48.4%.Phenylglyoxylic acid was synthesized starting from styrene by only one step reaction. This route is more convenient and friendly to environment than that which CuCN is used as starting materials and phCOCN is used as intermediate.