benzyl 2-(phenylmethoxycarbonylamino)-4-(phenylmethoxycarbonylaminosulfamoyl)butanoate

O1-苄基O2-叔-丁基4-亚甲基吡唑烷-1,2-二羧酸酯

benzyl 4-methylidenepyrazolidine-1-carboxylate

4-氧代-1,2-吡唑烷二甲酸 1-叔丁酯 2-苄酯

benzyl N-amino-N-benzylcarbamate