Ethyl isocyanate is the leading product of HAIDA chemical co.ltd.It can be synthesised a lot of medicine ,such as (4-piperidinglmethyl)purinesˇ˘(2-heterocyclylalkyl)imi- dazopyridineˇ˘N-phenyl-N-(4-piperidingl)amideˇ˘1-(1,3-Dioxolan-2-ylmethyl)-1H-imidazolesˇ˘1H-1,2,4-triazoles.