5-propan-2-yl-2,5-dihydro-1H-1,2,4-triazin-6-one

3-methyl-2-[[(E)-(6-oxocyclohexa-2,4-dien-1-ylidene)methyl]amino]butanoic acid

3-methyl-2-[[2-(phenylmethoxycarbonylamino)acetyl]amino]butanoic acid

对硝基苯酚

2-[[2-[[3-methyl-2-(phenylmethoxycarbonylamino)butanoyl]amino]acetyl]amino]acetic acid