间硝基苯酚

氰乙酸乙酯

(triphenylphosphoranylidene-hydrazono)-acetic acid ethyl ester

ethyl hexahydro-2-oxo<1,2>diazeto<1,2-a>pyridazine-1-carboxylate

tert-butyl 1,4,5,5-tetrahydropyriadazine-3-carboxylate