This document describes a new class of substituted cyclopentyl compounds useful for therapeutic purposes. Specifically, it describes cyclopentyl acetic acid amides containing substituents that are obtainable by condensing cyclopentyl acetic acid or derivatives with ammonia, amines or ureas. The document provides an example for synthesizing cyclopentyl-bromo-acetamide in three steps: 1) brominating cyclopentyl acetic acid, 2) converting it to the acetylchloride derivative, and 3) reacting it with aqueous ammonia. These compounds have sedative properties and can be used as intermediates for producing other therapeutic agents or used directly as therapeutics.