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.

1-Benz­yl-3-(2-pheneth­yl)benzimidazolium bromide monohydrate

The title compound, C₂₂H₂₀N₂⁺·Br⁻·H₂O, was synthesized from 1-benzyl­benzimidazole and 2-bromo­ethyl­benzene in dimethyl­formamide. The dihedral angle between the two phen­yl rings is 70.6 (1)°. These phen­yl rings make dihedral angles of 52.99 (9) and 83.03 (8)° with the benzimidazole ring system. The crystal structure is stabilized by inter­molecular C—H...Br and O—H...Br hydrogen-bond inter­actions.

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.

Ethyl 3-methyl-1-oxo-4H-1,4-benzothia­zine-2-carboxyl­ate

The crystal structure of the title compound, C₁₂H₁₃NO₃S, is stabilized by inter­molecular N—H...O hydrogen bonds, which are formed between the NH groups and the sulfoxide O atoms.

1-Benzyl-2-[1-(5-methyl-1H-pyrazol-3-yl)-2-phenyl­ethyl]benzimidazole

The title compound, C₂₆H₂₄N₄, contains one pyrazole ring and two phenyl rings, which are nearly perpendicular to the benzimidazole ring system. In the structure, there is one intra­molecular C—H...N hydrogen-bonding inter­action.