Twisted imide bond in non-cyclic imides. Synthesis, structural and vibrational properties N,N-bis(furan-2-carbonyl)-4-chloroaniline

SAEED, AAMER; ERBEN, MAURICIO FEDERICO; BOLTE, MICHAEL

JOURNAL OF ORGANIC CHEMISTRY

AMER CHEMICAL SOC

Lugar: Washington; Año: 2012 vol. 77 p. 4688 - 4695

0022-3263

A novel imide compound (C16H10ClNO4) was synthesized in a single step by the reaction of 2-furoic acid with 4-chloroaniline in a 2:1 molar ratio using carbonyldiimidazole (CDI) in dry THF. The structure was supported by spectroscopic and elemental analyses and the single-crystal X-ray diffraction data. Crystallographic studies revealed that the compound crystallized in a monoclinic system with space group P21/c and unit cell dimensions a = 12.2575(5) Å, b = 7.7596(2) Å,c = 15.0234(7) Å, α = γ = 90°, β = 92.771(4)°, V = 1427.25(10) Å3, Z = 4. The imide bond is twisted, and the OC−N−C(O) units deviate significantly from planarity with dihedral angles around the imide group reaching ca. −150.3° (C1−N1−C2−O21 = −148.8° and C2−N1−C1−O11 = −151.9°). The nonplanarity of the imide moiety and the related conformational properties are discussed in a combined approach that includes the analysis of the vibrational spectra together with theoretical calculation methods, especially in terms of natural bond orbital (NBO) calculations.