Eth­yl 4-chloro-3-oxo-2-(phenyl­hydrazono)butyrate

The title compound, C₁₂H₁₃ClN₂O₃, adopts a keto–hydrazo tautomeric form stabilized by an intra­molecular N—H...O hydrogen bond. The configuration around the C=N bond is trans. The dihedral angle between the aromatic ring and the aliphatic chain is 5.52 (9)°. Symmetry-related mol­ecules are linked via C—H...O hydrogen bonds to form chains along the b axis.

O,O-Bis(2-tert-butyl-4-methyl­phenyl) chloro­thio­phospho­nate

The title compound, C₂₂H₃₀ClO₂PS, displays distorted tetrahedral geometry around the P atom. The dihedral angle between the benzene rings is 43.7 (4)°. The aromatic rings have unusual endocyclic angles as a result of the steric effects of the tert-butyl groups. The mol­ecules are linked by weak C—H...π interactions.

O,O-Bis(2-tert-but­yl-4-methoxy­phen­yl) chloro­thio­phospho­nate

The title compound, C₂₂H₃₀ClO₄PS, displays distorted tetra­hedral geometry around the P atom. The dihedral angle between the benzene rings is 41.2 (2)°. Because of the steric effects of the tert-but­yl groups, the aromatic rings have unusual endocyclic angles. The mol­ecules are linked by weak C—H...π inter­actions.