1,2,4-Triazine-1-carboxylic acid, 1,6-dihydro-5-(methylthio)-6-oxo-3-phenyl, ethyl ester. Mixture with either 1,2,4-Triazin-6-yl-carbamic acid, 5-(methylthio)-3-phenyl-, ethyl ester or 1,2,4-Triazine- 1-carboxylic acid, 1,6-dihydro-6-imino-5-(methylthio)- 3-phenyl-, ethyl ester: NSC606697