A kind of relative substance PZB of Alfacalcidol and its preparation method and application

The invention discloses a kind of relative substance PZB of Alfacalcidol, i.e. 5,7,10 (19) triolefin of (1 α, 3 β, 5Z, 7E) 9,10 open loop ergot steroid, 1,3 glycol, with and preparation method thereof, belong to technical field of pharmaceutical chemistry.The relative substance PZB of the Alfacalcidol of high-purity of the present invention, it can make the contamination levels product in the analysis of Alfacalcidol finished product detection, so as to promote the analysis of Alfacalcidol finished product detection to the accurate positionin of impurity and qualitative, be conducive to strengthen the control to the impurity, and then improve Alfacalcidol final product quality.Method raw material provided by the invention is cheap and easily-available, easy to operate, favorable reproducibility, HPLC purity >=99.5%.