Syntheses and structures of 1-[2,2-dichloro-1-hydroxy-3-(4-methylphenyl)-3-oxopropyl]urea and 1-[2,2-dichloro-3-(4-fluorophenyl)-1-hydroxy-3-oxopropyl]urea

The title compounds, C₁₀H₉Cl₂FN₂O₃, (I), and C₁₁H₁₂Cl₂N₂O₃, (II), are α,α-dihalo-β-diketone urea derivatives, which contain 4-fluorophenyl and ptolyl groups, respectively. The conformation about the C_O—C_Cl2—C_O—N_u (O = keto, Cl2 = dichloro, u = urea) bond is anti in (I) and gauche in (II). In the crystals of both compounds, O—H․ ․ ․O hydrogen bonds generate inversion dimers and the dimers are linked into (100) layers by N—H․ ․ ․O hydrogen bonds. The Hirshfeld surface analyses of the crystal structures indicate that the most important contributions for the crystal packings are from H․ ․ ․O/O․ ․ ․H (22.3%), H․ ․ ․H (20.9%), H․ ․ ․Cl/Cl․ ․ ․H (15.6%) and H․ ․ ․C/C․ ․ ․H (10.3%) for (I) and H․ ․ ․H (31.7%), H․ ․ ․O/O․ ․ ․H (25.1%), H․ ․ ․Cl/Cl․ ․ ․H (21.1%) and H․ ․ ․C/C․ ․ ․H (9.5%) for (II).