3,4-二甲基-5-吡唑啉酮

(Z)-3-(3,4-Dimethyl-5-oxo-2,5-dihydro-pyrazol-1-yl)-2-methyl-but-2-enoic acid

2,3,6,7-tetramethyl-5H-pyrazolo[5,1-b][1,3]oxazin-5-one