Synthesis, Molecular and Crystal Structure of Two Tricyclic N-Aminoimides

Two new N-aminoimides, 2-amino-4,7-epoxy-3a,4,7,7a-tetrahydro-1H-isoindole- 1,3(2H)dione (I) and 2-amino-8-isopropyl-5-methyl-4,7-ethane-3a,4,7,7a-tetrahydro- 1H-isoindole-1,3(2H)-dione (II), have been synthesized. Both compounds are exo,cis isomers. Crystals of (I) and (II) are noncentrosymmetric with two crystallographically independent molecules (Z’ = 2) in the asymmetric unit. The N-amine groups of the symmetry independent molecules differ in their environment, forming single or bifurcated N–H...O hydrogen bonds. Voluminous hydrocarbon parts evoke orthogonal electrostatic interactions between the imide ring and carbonyl or ether O atoms in (II) and (I), respectively, with C/N...O distances smaller than 3.2 (the shortest being of 2.9 ).