Crystal structure of 2,4,6-tri-methyl-benzoic anhydride.

ABSTRACT: The title compound, C₂₀H₂₂O₃, was formed in the reaction between 2,4,6-tri-methyl-benzoic acid and N,N-diiso-propyl-ethyl-amine in the presence of 1,3-di-chloro-1,3-bis-(di-methyl-amino)-propenium hydrogen dichloride, and was recrystallized from diethyl ether solution. It is the first exclusively alkyl-substituted benzoic anhydride to have been structurally characterized. The asymmetric unit consists of a half mol-ecule, the other half of which is generated by twofold rotation symmetry; the dihedral angle between the symmetry-related aromatic rings is 54.97?(3)°. The geometric parameters of the aromatic ring are typical of those for 2,4,6-tri-methyl-phenyl substituted groups. The C=O and C-O bond lengths are 1.1934?(12) and 1.3958?(11)?Å, respectively, and the angle between these three atoms (O=C-O) is 121.24?(9)°. In the crystal, mol-ecules are linked by weak C-H?O hydrogen bonds and C-H?? inter-actions. The packing features wavy chains that extend parallel to [001].

SUBMITTER: Land MA 

PROVIDER: S-EPMC5683502 | biostudies-literature | 2017 Nov

REPOSITORIES: biostudies-literature