N-[2-(4-Chlorophenoxy)phenyl]-4-methyl-1-piperazinecarboxamide Hydrochloride-d8 is the isotope labelled analog of N-[2-(4-Chlorophenoxy)phenyl]-4-methyl-1-piperazinecarboxamide Hydrochloride (C375200); a reagent in the synthesis of Loxapine Succinate (L472750) which is a D2/D4-dopamine receptor antagonist. Also a serotonergic receptor antagonist and dibenzoxazepine antipsychotic agent.