Structural changes in chlorpropamide at high pressure

The crystalline structure of a molecular crystal of chlorpropamide C10H13ClN2O3S is studied by X-ray diffraction at high pressures of up to 4.2 GPa at room temperature. Under normal conditions the structure of chlorpropamide has orthorhombic symmetry with the space group P212121. At high pressures P > 1.2 GPa, a polymorphic phase transition into the monoclinic phase with the space group P21 is observed. The baric dependences of the lattice parameters and unit-cell volumes are obtained for both phases of chlorpropamide.