Substituted clonidine derivatives. II. Ethyl 3,5-dichloro-4-(1-isobutyrylimidazolidin-2-ylideneamino)benzoate and ethyl 3,5-dichloro-4-(1,3-diisobutyrylimidazolidin-2-ylideneamino)benzoate

In the title compounds, C₁₆H₁₉Cl₂N₃O₃ (R₁ = H, R₂ = COCHMe₂), (I), and C₂₀H₂₅Cl₂N₃O₄ (R₁ = R₂ = COOCHMe₂), (II), the imidazolidine rings adopt half-chair conformations. Compound (I) exists in the imidazolidine form. The dihedral angles between the phenyl and imidazolidine rings are 80.95(6)° for (I), and 66.7(2) and 67.5(2)° for (II). In (I), the glide-related molecules are involved in N-H...N intermolecular hydrogen bonds.

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