Abstract: A novel process for producing optically active 2-(2-fluorobiphenyl-4-yl)propanoic acid is disclosed. This production process is characterized in that a compound of formula [1] is reacted with magnesium and so forth to prepare an organometallic reagent, which is reacted with a compound of formula [2] in the presence of a catalytic amount of a nickel compound and a catalytic amount of an optically active compound of formula [3] to obtain a compound represented by formula [4] which is subsequently converted to a compound represented by formula [5] or a pharmaceutically acceptable salt thereof.

Abstract: A novel process for producing optically active 2-(2-fluorobiphenyl-4-yl)propanoic acid is disclosed. This production process is characterized in that a compound of formula [1] is reacted with magnesium and so forth to prepare an organometallic reagent, which is reacted with a compound of formula [2] in the presence of a catalytic amount of a nickel compound and a catalytic amount of an optically active compound of formula [3] to obtain a compound represented by formula [4] which is subsequently converted to a compound represented by formula [5] or a pharmaceutically acceptable salt thereof.

Abstract: A compound represented by formula (IA) or a pharmaceutically acceptable salt thereof, which is useful for the treatment or prevention of diseases such sleep disorder, depression, anxiety disorder, panic disorder, schizophrenia, drug dependence, Alzheimer's disease, Parkinson's disease, Huntington's chorea, eating disorder, pain, gastrointestinal diseases, epilepsy, inflammation, immune-related diseases, endocrine-related diseases, and hypertension, and of which the action relies on an orexin (OX) receptor antagonistic activity.