Crystal structure and solid-state behavior of aspirin anhydride crystals

The crystal structure and solid-state behavior of aspirin anhydride were determined using single-crystal X-ray techniques and microscopic examination of the reacting crystals. The crystal structure and solid-state conformation of aspirin anhydride were similar to those of related compounds. The crystal packing of aspirin anhydride allows the initial product of the solid-state reaction to be predicted; however, this prediction could not be tested because the thermal degradation products reported in the literature appear to be those obtained from reaction in a liquid state.