L-Tryptophan Methyl Ester is the acidic-free form of L-Tryptophan Methyl Ester Hydrochloride (T895010), which is an amino acid derivative that may be used to prepare the corresponding amino acid amide L-Trytophanamide Hydrochloride. Also, it is an intermediate used in the synthesis of (1S,3S)-1-(1,3-Benzodioxol-5-yl)-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole-3-carboxylic Acid Methyl Ester (B200020), which is a Tadalafil (T004500) derivative and used in the preparation of pyrazinopyridoindole derivatives for their PDE5 inhibitory activity.