The crystal structure of acalabrutinib dihydrate Form III has been refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Acalabrutinib dihydrate Form III crystallizes in space group P21 (#4) with a = 8.38117(5), b = 21.16085(14), c = 14.12494(16) Å, β = 94.5343(6)°, V = 2497.256(20) Å3, and Z = 4 (Z′ = 2) at 295 K. The crystal structure consists of herringbone layers parallel to the ac-plane. Hydrogen bonds between the acalabrutinib and water molecules generate a three-dimensional framework. Each water molecule acts as a donor in two hydrogen bonds and as an acceptor in at least one hydrogen bond. Amino groups and pyridine N atoms link the acalabrutinib molecules into dimers. The powder pattern has been submitted to ICDD for inclusion in the Powder Diffraction File™ (PDF®).
