(1Z)-1-(1-Benzo-furan-2-yl)ethanone oxime

Crystal structure of 1-(5-bromo-1-benzo-furan-2-yl)ethanone oxime

The title compound, C₁₀H₈BrNO₂, is almost planar (r.m.s. deviation for the non-H atoms = 0.031 Å) and the conformation across the C=N bond is trans. Further, the O atom of the benzo­furan ring is syn to the N atom of the oxime group. In the crystal, inversion dimers linked by pairs of O—H⋯N hydrogen bonds generate R₂²(6) loops. Very weak aromatic π–π stacking inter­actions [centroid–centroid separations = 3.9100 (12) and 3.9447 (12) Å] are also observed.

Crystal structure of ethyl (6-hy-droxy-1-benzo-furan-3-yl)acetate sesquihydrate

In the title hydrate, C12H12O4·1.5H2O, one of the water mol-ecules in the asymmetric unit is located on a twofold rotation axis. The mol-ecule of the benzo-furan derivative is essentially planar (r.m.s. deviation for the non-H atoms = 0.021 Å), with the ester group adopting a fully extended conformation. In the crystal, O-H⋯O hydrogen bonds between the water mol-ecules and the hy-droxy groups generate a centrosymmetric R 6 (6)(12) ring motif. These R 6 (6)(12) rings are fused, forming a one-dimensional motif extending along the c-axis direction.

2-(6-Hy-droxy-1-benzo-furan-3-yl)acetamide

In the title compound, C₁₀H₉NO₃, the dihedral angle between the benzo­furan ring system (r.m.s. deviation for the non-H atoms = 0.009 Å) and the –C—C(O)—N– segment is 83.76 (1)°. In the crystal, mol­ecules are linked by N—H⋯O and O—H⋯O hydrogen bonds, generating (001) sheets, which feature C(4) and C(10) chains.