The title mol-ecule, C(16)H(13)N(3)O(7), is slightly twisted, with the dihedral angle between the two benzene ring planes being 17.4 (1)°. An intra-molecular N-H⋯O hydrogen bond is observed. In the crystal, weak C-H⋯O hydrogen bonds link the mol-ecules into chains along the b axis.

In the title compound, C(14)H(21)NO(4)S, the O-S-O angle is 120.06 (11)°, with the S atom adopting a distorted tetra-hedral geometry. In the crystal, N-H⋯O hydrogen bonds connect the mol-ecules along the a axis, generating an infinite chain. The disordered C atoms of the isobutyl group were refined with the C-C distances restrained to 1.52 (1) Å and the occupancy ratio refined to 0.504 (3):0.49...

The title compound PBPEA, C(10)H(7)Br(5)O(2), has its ethyl acetate portion nearly orthogonal to the benzene ring, with a C-C-C-C torsion angle of 88.3 (5)°. The packing involves an inter-molecular contact with a Br⋯Br distance of 3.491 (1) Å, having C-Br⋯Br angles of 173.4 (2) and 106.0 (2)°. The crystal studied was an inversion twin.

The title compound, C(12)H(14)N(2)O(3)S, adopts a cis-trans geometry of the thio-urea group and is stabilized by intra-molecular hydrogen bonds between the carbonyl O atoms and the H atom of the thio-amide group and by a C-H⋯S interaction. Mol-ecules are linked by two inter-molecular hydrogen bonds (C-H⋯O and N-H⋯O), forming a one-dimensional chain parallel to the c axis.

In the title mol-ecule, C(10)H(11)NO(5), the methyl C atom deviates by 0.830 (6) Å from the mean plane of the remaining non-H atoms. In the crystal, weak C-H⋯O hydrogen bonds link the mol-ecules into layers parallel to the bc plane.