Crystalline base of compound trans-1-((1R,3S)-6-chloro-3-phenylindan-1-yl)-3,3-dimethylpiperazine, processes for the preparation of purified free base or salts of this compound, pharmaceutical compositions comprising the base and medical use thereof, including for treatment of schizophrenia and other psychotic disorders.本發明係關於化合物反式-1-((1R,3S)-6-氯基-3-苯基茚滿-1-基)-3,3-二甲基六氫吡之結晶鹼,用於製備該化合物之純化型自由鹼或鹽類之方法,含有該鹼之醫藥組成物及其醫學用途,包括用於治療精神分裂症及其它精神性病症。