Two‐dimensional hydrogen‐bonded networks in two novel glycoluril derivatives

Two new glycoluril derivatives, namely diethyl 6‐ethyl‐1,4‐dioxo‐1,2,2a,3,4,6,7,7b‐octahydro‐5H‐2,3,4a,6,7a‐pentaazacyclopentacd]indene‐2a,7b‐dicarboxylate, C₁₄H₂₁N₅O₆, (I), and 6‐ethyl‐2a,7b‐diphenyl‐1,2,2a,3,4,6,7,7b‐octahydro‐5H‐2,3,4a,6,7a‐pentaazacyclopentacd]indene‐1,4‐dione, C₂₀H₂₁N₅O₂, (II), both bearing two free syn‐urea NH groups and two ureidyl C=O groups, assemble the same one‐dimensional chains in the solid state running parallel to the 010] direction via N—H...O hydrogen bonds. Furthermore, the chains of (I) are linked together into two‐dimensional networks via C—H...O hydrogen bonds.