3a,6a-Dipropoxycarbonylglycoluril (dipropyl 2,5-dioxoperhydroimidazo[4,5-d]imidazole-3a,6a-dicarboxylate)

Abstract

Key indicators: single-crystal X-ray study; T = 300 K; mean (C-C) = 0.002 Å; disorder in main residue; R factor = 0.056; wR factor = 0.152; data-to-parameter ratio = 15.6.The title compound, C 12 H 18 N 4 O 6 , exhibits a hydrogenbonding network, which contains intermolecular classical N-HÁ Á ÁO C(imidazolone rings) hydrogen bonds and, in addition, intermolecular C-HÁ Á ÁO interactions that stabilize the crystal structure. Two ethyl groups are each disordered over two positions, with site occupancy factors in a ratio of ca 3:2.

Supramolecular Rhombic Grids Formed from Bimolecular Building Blocks

“…The two unsubstituted ureidyl N−H groups are directed roughly parallel to one another and define a DD H-bonding array. The synthesis of compounds L1 − L3 was achieved by Pd-catalyzed Sonogashira coupling reactions between glycoluril derivatives 5 − 7 and 4-ethynylpyridine in 67−78% yield (Scheme ). , For the preparation of L4 , we conducted the Pd-catalyzed Heck coupling reaction between 5 and 4-vinylpyridine in 90% yield (Scheme ). Details of the synthesis and complete characterization of L1 − L4 are given in the Supporting Information.…”