The compound is produced as the (S)-enantiomer, with an empirical formula of C16H21NO2, molecular weight of 259.34, and the following chemical structure: Ramelteon is freely soluble in organic solvents, such as methanol, ethanol, and dimethyl sulfoxide; soluble in 1-octanol and acetonitrile; and very slightly soluble in water and in aqueous buffers from pH 3 to pH 11.