2-(2-Methyl­phen­yl)-N-(1,3-thia­zol-2-yl)acetamide

In the title compound, C₁₂H₁₂N₂OS, the dihedral angle between the benzene and thia­zole rings is 83.5 (7)°. The acetamide group is almost coplanar with the thia­zole ring, being twisted from it by 4.2 (9)°. In the crystal, pairs of N—H...N hydrogen bonds link mol­ecules into inversion dimers, generating R₂²[8] loops; the dimers are stacked along [001].

4-[(4-Acetyl­phen­yl)amino]-2-methyl­idene-4-oxo­butanoic acid

In the title compound, C₁₃H₁₃NO₄, the N—C(=O) bond length of 1.354 (2) Å is indicative of amide-type resonance. The dihedral angle between the mean planes of the benzene ring and oxo­amine group is 36.4 (3)°, while the mean plane of the 2-methyl­idene group is inclined by 84.2 (01)° from that of the oxo­amine group. In the crystal, classical O—H...O hydrogen bonds formed by the carb­oxy­lic acid groups and weak N—H...O weak inter­actions formed by the amide groups and supported by weak C—H...O inter­actions between the 2-methyl­idene, phenyl and acetyl groups with the carb­oxy­lic acid, oxo­amine and acetyl O atoms, together link the mol­ecules into dimeric chains along [010]. The O—H...O hydrogen bonds form R₂²(8) graph-set motifs.

4-[(4-Bromo­phenyl)amino]-2-methyl­idene-4-oxo­butanoic acid

In the title compound, C₁₁H₁₀BrNO₃, two independent mol­ecules (A and B) crystallize in the asymmetric unit. The dihedral angles between the mean planes of the 4-bromo­phenyl ring and amide group are 24.8 (7) in mol­ecule A and 77.1 (6)° in mol­ecule B. The mean plane of the methyl­idene group is further inclined by 75.6 (4) in mol­ecule A and 72.5 (6)° in mol­ecule B from that of the amide group. In the crystal, N—H...O hydrogen bonds formed by amide groups and O—H...O hydrogen bonds formed by carb­oxy­lic acid groups are observed and supported additionally by weak C—H...O inter­actions between the methyl­idene and amide groups. Together, these link the mol­ecules into chains of dimers along [110] and form R₂²(8) graph-set motifs.