In the title compound, C(8)H(10)N(2)O(3), the hydrazinecarboxyl-ate group is twisted from the furan ring by 6.98 (17)°. In the crystal, the mol-ecules are linked into one-dimensional chains running along the c axis by N-H⋯O hydrogen bonds.

In the title compound, C(12)H(12)O(4), the dihedral angle between the plane through the phenyl ring and the mean plane of the side chain is approximately 14°. The mol-ecules, which contain an intra-molecular O-H⋯O hydrogen bond, are linked end-to-end by weak C-H⋯O inter-molecular hydrogen-bonding contacts, forming infinite one-dimensional chain systems in the crystal structure.

In the crystal structure of the title compound, C(10)H(11)NO(5), inter-molecular O-H⋯O hydrogen bonds link the mol-ecules into chains along the b-axis direction. Weak C-H.·O hydrogen bonds also occur.

In the title mol-ecule, C(13)H(14)O(3)S(2), the thio-phene and benzene rings form a dihedral angle of 13.86 (13)°. In the crystal, weak inter-molecular C-H⋯O hydrogen bonds link the mol-ecules into layers parallel to the ab plane.

The title Schiff base, C(27)H(33)N(7), is a tripodal amine displaying C(3) symmetry, with the central tertiary N atom lying on the threefold crystallographic axis. The N-CH(2)-CH(2)-N conformation of the pendant arms is gauche [torsion angle = 76.1 (3)°], which results in a claw-like mol-ecule, with the terminal aniline groups wrapped around the symmetry axis. The lone pair of the apical N atom...

In the mol-ecule of the title compound, C(17)H(17)NO(5)S, the two aromatic rings are oriented at an angle of 30.13 (10)°. The ethyl acetate group assumes an extended conformation. Mol-ecules are linked into C(7) chains running along the a axis by inter-molecular C-H⋯O hydrogen bonds, and the chains are crosslinked via C-H⋯π inter-actions, with the sulfonyl-bound phenyl ring acting as an acceptor.