(E)-tert-Butyl 4-(N′-hy­droxy­carbam­­imid­o­yl)piperazine-1-carboxyl­ate

In the title compound, C₁₀H₂₀N₄O₃, the piperazine ring adopts a chair conformation. The mol­ecule adopts an E conformation across the C=N double bond, with the –OH group and the piperazine ring trans to one another. Further, the H atom of the hy­droxy group is directed away from the NH₂ group. An intra­molecular N—H...O contact occurs involving the NH₂ group and the oxime O atom. In the crystal, mol­ecules are linked via strong N—H...O and O—H...N hydrogen bonds with alternating R₂²(6) and C(9) motifs into tetra­meric units forming R₄⁴(28) motifs.

6-[4-Chloro-2-(trifluoro­meth­yl)phen­yl]-3-fluoro-2-methyl­pyridine

In the title compound, C₁₃H₈ClF₄N, the dihedral angle between the benzene and pyridine rings is 59.8 (3)°. In the crystal, mol­ecules are stacked in columns along the b axis through weak C—H...π inter­actions.

(E)-3-Chloro-N′-hy­droxy­benzene-1-carboximidamide

The title compound, C₇H₇ClN₂O, crystallizes with two independent mol­ecules in the asymmetric unit. The compound adopts an E configuration across the C=N double bond, as the –OH group and the benzene ring are on opposite sides of the double bond while the H atom of the hy­droxy group is directed away from the –NH₂ group. In the crystal, mol­ecules are linked to one another through O—H...N and N—H...O hydrogen bonds, forming chains along [010].