 The hydrochloride salt exists as a very fine crystalline powder; it is hygroscopic and thus tends to form clumps, resembling something like powdered sugar.Its color can range from pure white to a yellowish-tan and has a slight odor that strengthens as it colors.Impurities are likely to consist of either pyrrolidine or alpha-dibrominated alkylphenones—respectively, from either excess pyrrolidine or incomplete amination during synthesis.