4-Chloro-N-(2-hydroxypropyl)benzeneacetamide-d6 is the isotope labelled analog of 4-Chloro-N-(2-hydroxypropyl)benzeneacetamide (C368125); a reagent in the synthesis of Lorcaserin Hydrochloride (L469890) which is a novel selective 5-HT2C-receptor agonist for the treatment of obesity.