Polar crystal of vanillylformamide through replacement of the alkene by an isosteric formamide group

摘要

Vanillylformamide [systematic name: N -(4-hy-droxy-3-meth-oxy-benz-yl)form-amide], C 9 H 11 NO 3 , ( II ), has been synthesized from vanillyl-amine hydro-chloride and studied by single-crystal X-ray diffraction. Compound ( II ) and the well known biologically active eugenol compound ( I ) can be considered to be `isosteres' of each other, since they share comparable mol-ecular shape and volume. The product ( II ) crystallizes in the space group P 1. In the crystal, the vanillylformamide mol-ecules are linked mainly by N—H?O, O—H?O and C sp 2 —H?O hydrogen bonds, forming infinite two-dimensional polar sheets. These two-dimensional layers pack in a parallel fashion, constructing a polar three-dimensional network. Except for van der Waals forces and weak C sp 3 —H?O hydrogen bonds, there are no significant inter-mol-ecular inter-actions between the layers. A Cambridge Structural Database search revealed that vanillyl-amide-related crystals are scarce.