(1-[(4-Chlorophenyl)(phenyl)methyl]-4-nitrosopiperazine); 1-((4-Chlorophenyl)(phenyl)methyl)-4-nitrosopiperazine; Piperazine, 1-(p-chloro-a-phenylbenzyl)-4-nitroso; Piperazine, 1-[(4-chlorophenyl)phenylmethyl]-4-nitros; 1-[(4-Chlorophenyl)phenylmethyl]-4-nitrosopiperazine;N-Nitroso Hydroxyzine EP Impurity A;