Synthesis of O-Alkylbenzohydroximoyl Iodides and a Comparison of their Structures to other Oxime Derivatives

The first general synthesis of (Z)-O-alkylbenzohydroximidoyl iodides [ArC(I)=NOR] is reported. X-ray crystallographic structures of two of these compounds confirm that they are in the Z-configuration: p-NO2ArC(I)=NOCH3 crystallizes in space group Pnma with lattice constants a = 12.682(2) A, b = 6.5217(15) A, and c = 11.755(2) A, and p-ClArC(I)=NOCH3 crystallizes in space group P21/n with lattice constants a = 15.670(4) A, b = 5.742(4) A, and c = 27.156(7) A and beta angle 102.71(2). Their structures are compared to other O-alkylbenzohydroximoyl halides including p-NO2ArC(F)=NOCH3 which crystallizes in space group P21/c with lattice constants a = 3.8475(10) A, b = 22.501(5) A, and c = 10.088(2) A and beta angle 91.130(11). The synthesis of two additional compounds containing the N-alkoxyimine moiety {methyl (Z)-O-methyl-4-nitrobenzothiohydroximate [p-NO2ArC(SCH3)=NOCH3] which crystallizes in space group P21/n with lattice constants a = 11.8046(15) A, b = 7.0774(10) A, and c = 12.2741(15) A and beta angle 100.401(9) and (Z)-O-methyl-4-nitrobenzohydroximoyl azide [p-NO2ArC(N3)=NOCH3] which crystallizes in space group P21/c with lattice constants a = 11.753(2) A, b = 11.310(3) A, and c = 7.351(2) A and beta angle 103.805(15) are also reported. Their structures are compared to (Z)-ethyl benzohydroximate [PhC(OEt)=NOH] and (Z)-O-methyl-4-nitrobenzohydroximoyl cyanide [p-NO2ArC(CN)=NOCH3] respectively. Characterizations include spectrometric identifications employing IR, 1H-NMR, 13C-NMR and mass spectrometry. X-ray structures of several N-alkoxyimines, including the newly synthesized N-alkoxyimidoyl iodides and azide, have been performed, and these structures unambiguously show the geometric configuration (E vs. Z) of these compounds.