Waste-free solid state syntheses

Waste-free solid-state syntheses might be particularly valuable in synthesis or derivatization of pharmaceuticals. For example, the potassium-channel activator 38 exhibits a cleavage plane that is reminiscent of the (010) cleavage plane of a-cinnamic acid 1 (Fig. 2.1.3) even though the hydrogen bond dimers in the double layers consist of 3D-molecules (Fig. 2.1.24). Clearly, solid-state reactivity is predicted and important chemical selectivities are expected. 

The need to implement green chemistry principles (e.g., safer solvents, less hazardous chemical synthesis, atom economy, and catalysis) is a driving force toward the avoidance of the use of toxic organic solvents. A solvent-free or solid-state reaction obviously reduces pollution and reduces handling costs due to simplification of experimental procedure and workup technique and savings on labor. However, interest in the environmental control of chemical processes has increased remarkably in the last three decades as a response to public concern about the use of hazardous chemicals. Therefore, to improve the effectiveness of this method in preventing chemical waste, it is important to investigate its optimal conditions. 

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