Syntheses, Characterization And Biological Activities Of New Hydrazinyl Thiazolyl Coumarin Derivatives

Coumarin and thiazole are two important pharmacophores, the syntheses of which acquire great importance in medicinal chemistry due to the diverse pharmacological activities. The present study aims to synthesize some (45) new biologically active compounds by incorporating thiazole ring with coumarin nucleus. Two new series of hydrazinyl thiazolyl coumarin derivatives have been synthesized in four steps. The first step of the synthesis was the preparation of acetyl coumarins by Knoevenagel’s condensation of substituted salicyaldehydes with ethyl acetoacetate in the presence of catalytic amount of piperidine. In the second step, bromination of acetyl coumarins was carried out with bromine in order to yield the corresponding bromoacetyl coumarins. Thiosemicarbazones were synthesized in the third step by treating thiosemicarbazide with various substituted aldehydes and ketones in the presence of a catalytic amount of glacial acetic acid. The final step of the synthesis involved the preparation of two new series of hydrazinyl thiazolyl coumarins using Hantzsch cyclization protocol. One series of compounds was obtained by reacting 3-bromoacetyl coumarins with thiosemicarbazones derived from various substituted aldehydes, while the other series was furnished by treating thiosemicarbazones of substituted ketones with 3-bromoacetylcoumarins. All the synthesized compounds were fully characterized by IR, 1H and 13C NMR, elemental analysis and mass spectroscopy

Explaining Rejection Sensitivity among Adolescences as predicted by Perceived Differential Treatment of Parents

The aim of the present research was to investigate the relationship between differential parenting and rejection sensitivity in 200 (male=95; females=105) adolescences. It was hypothesized that differential parenting (Maternal/Paternal affection and control) was likely to predict rejection sensitivity (anxious & angry expectation) in adolescents. Differential Parenting Treatment subscale of Sibling Inventory of Differential Experiences (Daniels,&Plomin, 1985) and Children Rejection Sensitivity Scale (Downey, & Feldom, 1996) were used. The results revealed that there was a significant positive relationship between maternal/paternal affection and anxious expectation domain of rejection sensitivity while maternal/paternal control was negatively related with angry expectation domain of rejection sensitivity in adolescents. Maternal affection, maternal control, paternal affection, paternal control were more significant predictors of anxious expectation (39%) domain of rejection sensitivity than angry expectation (22%) domain among adolescents after controlling for the effects of covariates. The finding of the study was helpful for the family advisors to teach parents not to practice discrimination  in their child rearing towards any of their kid in light of the fact that can be prompt create feeling to be dismisses from their critical connections. More over these discoveries were useful for school guides to consolidate educational modules uniquely outline to lessens rejection

(E)-6-Bromo-3-{2-[2-(2-meth­oxy­benzyl­idene)hydrazin­yl]-1,3-thia­zol-4-yl}-2H-chromen-2-one

In the title compound, C20H14BrN3O3S, the mol­ecule adopts an E configuration about the central C=N double bond. The chromene ring system and the thia­zole ring are approximately planar [maximum deviations = 0.029 (3) and 0.007 (3) Å, respectively]. The chromene ring system is inclined at angles of 7.37 (12) and 13.90 (13)° with respect to the thia­zole and benzene rings, respectively, while the thia­zole ring makes a dihedral angle of 12.58 (15)° with the benzene ring. In the crystal, mol­ecules are connected by N—H⋯O hydrogen bonds, forming C(8) supra­molecular chains along the c axis

(E)-6-Bromo-3-{2-[2-(2-chloro­benzyl­idene)hydrazin­yl]thia­zol-5-yl}-2H-chromen-2-one dimethyl sulfoxide monosolvate

In the title compound C19H11N3O2SClBr·C2H6OS, the mol­ecule adopts an E configuration about the central C=N double bond. The chromene ring system and the thia­zole ring are approximately planar, with maximum deviations of 0.027 (2) and 0.003 (1) Å, respectively. The central thia­zole ring makes dihedral angles of 21.82 (9) and 5.88 (7)° with the chloro-substituted phenyl ring and the chromene ring, respectively. In the crystal, mol­ecules are connected via N—H⋯O, N—H⋯S and C—H⋯O hydrogen bonds, forming supra­molecular chains along the c axis. An intra­molecular C—H⋯O hydrogen bond occurs. π–π inter­actions are observed between the thia­zole and phenyl rings [centroid–centroid distance = 3.6293 (10) Å]. A short Br⋯Cl contact of 3.37 (6) Å also occurs

(E)-3-(2-{2-[1-(3-Hy­droxy­phen­yl)ethyl­idene]hydrazin­yl}-1,3-thia­zol-4-yl)-2H-chromen-2-one

In the title compound, C20H15N3O3S, the thia­zole ring is approximately planar, with a maximum deviation of 0.003 (1) Å, and makes dihedral angles of 7.44 (6) and 1.88 (6)° with the hy­droxy-substituted phenyl ring and the pyran ring, respectively. The hydroxyl group is disordered over two sets of sites, with an occupancy ratio of 0.567 (3):0.433 (3). In the crystal, the major disorder component mol­ecules are connected via bifurcated (three-centre) O—H⋯O and C—H⋯O hydrogen bonds, generating R 1 2(6) motifs and resulting in supra­molecular chains along the a axis. In the minor occupancy component, however, mol­ecules are connected via C—H⋯O hydrogen bonds, forming supra­molecular chains along the b axis. Furthermore, the crystal structure is stabilized by π–π inter­actions between the thia­zole rings [centroid–centroid distance = 3.5476 (7) Å]

3-{2-[2-(Diphenyl­methyl­ene)hydrazin­yl]thia­zol-4-yl}-2H-chromen-2-one

In the title compound, C25H17N3O2S, the coumarin ring system is essentially planar with a maximum deviation of 0.019 (2) Å. A weak intra­molecular C—H⋯O hydrogen bond stabilizes the mol­ecular structure, so that the coumarin plane is approximately coplanar with the thia­zole ring, making a dihedral angle of 2.5 (10)°. The two phenyl rings are nearly perpendicular to each other, with a dihedral angle of 81.44 (12)°. In the crystal structure, the mol­ecules are linked into an infinite chain along the b axis by inter­molecular C—H⋯O hydrogen bonds. Weak C—H⋯π inter­actions are observed between the chains

3-{2-[2-(3-Hy­droxy­benzyl­idene)hydrazin-1-yl]-1,3-thia­zol-4-yl}-2H-chromen-2-one hemihydrate

In the title compound, C19H13N3O3S·0.5H2O, both organic mol­ecules (A and B) exist in E configurations with respect to the acyclic C=N bond and have similar overall conformations. In mol­ecule A, the essentially planar thia­zole ring [maximum deviation = 0.010 (2) Å] is inclined at inter­planar angles of 11.44 (10) and 32.50 (12)°, with the 2H-chromene ring system and the benzene ring, respectively. The equivalent values for mol­ecule B are 0.002 (2) Å, 7.71 (9) and 12.51 (12)°. In the crystal structure, neighbouring mol­ecules are inter­connected into infinite layers lying parallel to (010) by O—H⋯O, O—H⋯N, N—H⋯O and C—H⋯O hydrogen bonds. Further stabilization of the crystal structure is provided by weak inter­molecular C—H⋯π and π–π [centroid–centroid distance = 3.6380 (19) Å] inter­actions

(E)-1-[1-(6-Bromo-2-oxo-2H-chromen-3-yl)ethyl­idene]thio­semicarbazide

The title compound, C12H10BrN3O2S, exists in an E configuration with respect to the C=N bond. The approximately planar 2H-chromene ring system [maximum deviation = 0.059 (1) Å] is inclined at a dihedral angle of 17.50 (5)° with respect to the mean plane through the thio­semicarbazide unit and an intra­molecular N—H⋯N hydrogen bond generates an S(5) ring. In the crystal structure, adjacent mol­ecules are linked by N—H⋯S hydrogen bonds, forming [010] chains built up from R 2 2(8) loops, such that each S atom accepts two such bonds. These chains are further inter­connected into sheets parallel to the ab plane via short Br⋯O inter­actions [3.0732 (13) Å] and a π–π aromatic stacking inter­action [3.7870 (8) Å] is also observed

6-Bromo-3-{2-[2-(diphenyl­methyl­ene)hydrazin­yl]-1,3-thia­zol-5-yl}-2H-chromen-2-one chloro­form monosolvate

In the title compound, C25H16BrN3O2S·CHCl3, the thia­zole ring is approximately planar [maximum deviation = 0.002 (3) Å] and makes dihedral angles of 10.75 (14) and 87.75 (15)/2.80 (14)° with the pyran ring system and the two terminal phenyl rings, respectively. The solvent mol­ecule is disordered over two sets of sites, with refined occupancies of 0.639 (7) and 0.361 (7). In the crystal, mol­ecules are connected via pairs of weak C—H⋯O inter­actions, forming centrosymmetric dimers. An intra­molecular C—H⋯O hydrogen bond generates an S(6) ring motif

3-{2-[2-(2-Fluoro­benzyl­idene)hydrazin­yl]-1,3-thia­zol-4-yl}-2H-chromen-2-one

In the title compound, C19H12FN3O2S, the chromene ring system and the thia­zole ring are approximately planar [maximum deviations of 0.023 (3) Å and 0.004 (2) Å, respectively]. The chromene ring system is inclined at angles of 4.78 (10) and 26.51 (10)° with respect to the thia­zole and benzene rings, respectively, while the thia­zole ring makes a dihedral angle of 23.07 (12)° with the benzene ring. The mol­ecular structure is stabilized by an intra­molecular C—H⋯O hydrogen bond, which generates an S(6) ring motif. The crystal packing is consolidated by inter­molecular N—H⋯O hydrogen bonds, which link the mol­ecules into chains parallel to [100], and by C—H⋯π and π–π [centroid–centroid distance = 3.4954 (15) Å] stacking inter­actions