Trazodone EP Impurity A (HCl),"4-(3-chlorophenyl)-1-[3-(3-oxo-2,3-dihydro[1,2,4]triazolo[4,3-a]pyridin-2-yl)propyl]piperazine 1-oxide hydrochloride ; 4-(3-Chlorophenyl)-1-[3-(3-oxo-[1,2,4]triazolo[4,3-a]pyridin-2(3H)-yl)propyl]piperazine 1-oxide hydrochloride ",Trazodone Impurity