Synthesis of functionalized chromene and spirochromenes using l-proline-melamine as highly efficient and recyclable homogeneous catalyst at room temperature

An efficient and recyclable homogeneous catalyst is developed using commercially cheap l-proline and melamine for the synthesis of chromenes and spirochromenes (spirooxindoles) via multicomponent reactions at room temperature. Systematic studies were conducted in order to achieve desired reactivity and recyclability of the catalyst using various α-amino acids and aromatic amines as donor-acceptor pairs. Among the screened combinations, l-proline and melamine (3:1 ratio; 3 mol% on total weight) was found to be best catalyst to give the desired products with excellent yields (up to 99%) in very short times (1–15 min) at room temperature in DMSO as solvent. The catalyst was recovered by adding EtOAc and reused up to 5 cycles without losing the catalytic activity.     

Novel synthesis of substituted N-(3-aryl-1,8-naphthyridin-2-yl) and N,N′-bis(3-aryl-1,8-naphthyridin-2-yl)benzene-1,4-diamines and 2-(4-((3-aryl-1,8-naphthyridin-2-yl)amino)phenyl)isoindoline-1,3-diones and their biological evaluation

A straightforward and highly efficient series of new substituted 3-aryl-1,8-naphthyridine derivatives 3a–e, 4a–e, and 6a–e were synthesized. Condensation dissimilar quantities of 2-chloro-3-aryl-1,8-naphthyridine 1a–e with benzene-1,4-diamine 2 and sodium ethoxide refluxing in ethanol solvent yielded the compounds 3a–e and 4a–e. The 2-(4-((3-aryl-1,8-naphthyridin-2-yl)amino)phenyl)isoindoline-1,3-diones 6a–e were obtained by treatment of compounds 3a–e with phthalic anhydride 5 in refluxing N,N-dimethylformamide is described. All synthesized compounds evaluated for their antimicrobial activity. The structures of the compounds have been proven on the established of spectral (IR, ¹H NMR, and ¹³C NMR) data and elemental analyses. The reaction will be characterized by good efficacy, easy workup, simple purification of the products, and availability of catalyst.     

An Efficient Microwave-Assisted Synthesis of Novel 2-{4-[(3-Aryl-1,8-naphthyridin-2-yl)amino]phenyl}-1H-benzo[de]isoquinoline-1,3(2H)-diones and Their Antimicrobial Activity

Russian Journal of General Chemistry - The Buchwald–Hartwig amination reaction between 2-chloro-3-aryl-1,8-naphthyridines and 2-(4-aminophenyl)-1H-benzo[de]isoquinoline-1,3(2H)-dione in the...     

Design,synthesis and biological evaluation of novel N1,N8-bis(((4-((5-aryl-1,3,4-oxadiazol-2-yl)methoxy)phenyl)amino)oxy)-1-naphthamide derivatives

A new series of 1,8-bis(4-((5-phenyl-1,3,4-oxadiazol-2-yl) methoxy)-substituted aryl) naphthalene-1,8-dicarboxamide derivatives (6a–j) were synthesized in the presence of POCl₃ and obtained good yields. All the synthesized novel compounds were characterized by IR, ¹H NMR, ¹³C NMR, HRMS spectroscopic data and elemental analysis. All the synthesized compounds evaluated for their antibacterial and antifungal activities. The antibacterial activity screened against Gram-positive bacteria Staphylococcus aureus and Gram-negative bacteria Escherichia coli and used standard reference drug ciprofloxacin. The antifungal activity screened against two pathogenic fungal strains Aspergillus niger and Candida albicans used a reference standard drug Voriconazole. All these compounds (6a–j) demonstrate good antibacterial and antifungal activity. Among them, compounds 6h and 6c show highest antibacterial and antifungal activity.     

Design,synthesis, biological evaluation and in silico molecular docking studies of novel benzochromeno[2,3-d]thiazolopyrimidine derivatives

Research on Chemical Intermediates - A new series of benzochromeno[2,3-d]thiazolopyrimidine derivatives were synthesized by involving...