1033-85-8

Upstream product

• 123-11-5 4-methoxy-benzaldehyde 
• 99-57-0 2-hydroxy-5-nitroaniline 
• 123-08-0 4-hydroxy-benzaldehyde 
• 369-36-8 6-fluoro-3-nitroaniline 
• 100-07-2 4-methoxy-benzoyl chloride 
• 70886-33-8 5-nitro-benzooxazole 
• 213468-59-8 S-methyl 3-oxo-3-(4-methoxylphenyl)propanedithioate 
• 29644-86-8 2-(4-methoxy-benzylidenamino)-4-nitro-phenol 

Downstream Products

• 54995-53-8 2-(4-methoxyphenyl)benzo[d]oxazol-5-amine 

Relevant academic research and scientific papers

Direct and practical synthesis of 2-arylbenzoxazoles promoted by activated carbon

(Matrix presented) 2-Arylbenzoxazoles were directly synthesized from substituted 2-aminophenols and aldehydes in the presence of activated carbon (Darco KB) in xylene under an oxygen atmosphere.

Mechanistic study of oxidative aromatization using activated carbon-molecular oxygen system in the synthesis of 2-arylbenzazoles:focus on the role of activated carbon

Nineteen activated carbons, including sixteen tailor-made and three commercially available ones, were employed to investigate their role in the one-pot synthesis of 2-arylbenzazoles starting from 2-aminophenol, 1,2-diaminobenzene, or 2-aminobenzenethiol, and aldehyde via oxidative cyclization of intermediate phenolic Schiff base promoted by the activated carbon-molecular oxygen system. Tailor-made activated carbons were prepared from wood, coconut shell, and coal by the steam activation method or the chemical activation method. All activated carbons were characterized to clarify their properties, such as metal contaminants, specific surface area, porosity, and surface functionality. After examining their effects on reactivity in the oxidative aromatization, we found that the essential role of activated carbon in this oxidation system is concerned not with metal contaminants, specific surface area, pore volume, mean pore diameter, and surface oxygen groups evolving as CO2 at 900 °C but with surface oxygen groups evolving as CO during heating at 900 °C, such as carbonyl groups on the surface of activated carbon. Additionally, in the synthesis of 2-arylbenzoxazole, it was found that activated carbon would also promote the cyclization of the intermediate Schiff base.

Deep eutectic solvent-catalyzed arylation of benzoxazoles with aromatic aldehydes

A novel and efficient methodology for the arylation of benzoxazoles with aromatic aldehydes catalyzed by deep eutectic solvent has been developed. The reaction smoothly proceeded with a wide range of substrates to give the desired products in high yields within short reaction time. Deep eutectic solvents are easily recovered and reused without significant loss of catalytic activity.

Phosphonium acidic ionic liquid: An efficient and recyclable homogeneous catalyst for the synthesis of 2-Arylbenzoxazoles, 2-Arylbenzimidazoles, and 2-Arylbenzothiazoles

A highly efficient and green strategy for the synthesis of 2-Arylbenzoxazoles, 2-Arylbenzimidazoles, and 2-Arylbenzothiazoles catalyzed by phosphonium acidic ionic liquid has been developed via the condensation of o-Aminophenol, o-phenylenediamines, and o-Aminothiophenol, respectively, with aldehydes. The reaction has a good yield, the broad substrate scope, and mild condition. Triphenyl(butyl-3-sulphonyl)phosphonium toluenesulfonate catalyst was easily obtained from cheap and available starting materials through a one-pot synthesis. Its structure was identified by 1H NMR, 13C NMR, 31P NMR, and FT-IR techniques. Other properties including thermal stability and acidity were determined by TGA and Hammett acidity function method. Interestingly, the catalyst can maintain its constantly outstanding performance till the fourth recovery.

Expanding Benzoxazole-Based Inosine 5′-Monophosphate Dehydrogenase (IMPDH) Inhibitor Structure-Activity As Potential Antituberculosis Agents

New drugs and molecular targets are urgently needed to address the emergence and spread of drug-resistant tuberculosis. Mycobacterium tuberculosis (Mtb) inosine 5′-monophosphate dehydrogenase 2 (MtbIMPDH2) is a promising yet controversial potential target

p-Toluenesulfonic acid-catalyzed metal-free formal [4?+?1] heteroannulation via N[sbnd]H/O[sbnd]H/S[sbnd]H functionalization: One-pot access to 2-aryl/hetaryl/alkyl benzazole derivatives

A concise and direct one-pot [4?+?1] synthetic strategy for the construction of 2-substituted benzazoles such as benzoxazoles and benzothiazoles has been disclosed in high yields (80–98%) by cascade coupling reaction of 2-amino(thio)phenols with β-oxodithioesters. The current approach enables N[sbnd]H/O[sbnd]H/S[sbnd]H functionalization in one-pot under solventless condition leading to diverse benzazoles without use of any external metal. A wide range of 2-amino(thio)phenols and β-oxodithioesters are compatible toward this transformation with excellent functional group tolerance. Furthermore, we preempt the wider implications of this novel strategy by demonstrating its compatibility toward versatile diversification of DNA Topoisomerase-II inhibitors.

A new superacid hafnium-based metal-organic framework as a highly active heterogeneous catalyst for the synthesis of benzoxazoles under solvent-free conditions

A new crystalline porous superacid material was prepared by sulfation of a Hf-MOF constructed from a 6-connected Hf node and 1,3,5-benzenetricarboxylate. The new superacid MOF with the presence of sulfate groups coordinated to a Hf-oxo cluster as superacid sites was found to be an effective heterogeneous catalyst for solvent-free heterocyclization for benzoxazole synthesis.

A novel and efficient route for the synthesis of 5-nitrobenzo[d]oxazole derivatives

In this paper, we report a novel and efficient route for the synthesis of 5-nitrobenzoxazole derivatives starting from 2-fluoro-5-nitroaniline and various benzoyl chloride derivatives under solvent-free conditions at 130 °C in the presence potassium carbonate. Benzoyl chlorides easily underwent nucleophilic acyl substitution followed by intramolecular cyclization via concomitant removal of fluorine to obtain the title compounds in high yields.

Metallomesogens derived from benzoxazoles-salicylaldimine conjugates

The synthesis, characterization, and mesomorphic properties of a new series of Schiff bases 2a-h and metal complexes 1a-h-M are prepared and their mesomorphic properties studied. Two single crystallographic structures of 2d (n=12, m=1) and 1g-Pd (n=m=12) were determined by X-ray analysis. Both compounds crystallize in a triclinic space group P-1. A dimeric structure formed by intermolecular H-bonds in 2d was observed, giving nematic phase due to a better aspect ratio. The central geometry at Pd2+ ion is nearly perfect square plane. All Schiff bases 2a-h formed N or/and SmC phases. The formation of mesophases of complexes 1a-h-M was strongly dependent on metal ions incorporated. All Cu2+, Ni2+ and Pd2+ complexes exhibited N or/and SmC phase, respectively. However, Zn2+ and Co2+ complexes were not mesogenic. The lack of mesomorphism was probably attributed to a preferred tetrahedral geometry at Zn2+ and Co2+ over a square-planar geometry at Cu2+ and Pd 2+.

Structure-activity relationships of benzimidazoles and related heterocycles as topoisomerase I poisons

A series of substituted 2-(4-methoxyphenyl)-1H-benzimidazoles were synthesized and evaluated as inhibitors of topoisomerase I. The presence of a 5-formyl-, 5-(aminocarbonyl)-, or 5-nitro group (i.e., substituents capable of acting as hydrogen bond accepters) correlated with the potential of select derivatives to inhibit topoisomerase I. In contrast to bi- and terbenzimidazoles, the substituted benzimidazoles that were active as topoisomerase I poisons exhibited minimum or no DNA binding affinity. 5-Nitro-2-(4-methoxyphenyl)-1H-benzimidazole exhibited the highest activity and was significantly more active than the 4-nitro positional isomer. The 5- and 6-nitro derivatives of 2-(4-methoxyphenyl)benzoxazole, 2-(4-methoxyphenyl)benzothiazole, and 2-(4-methoxyphenyl)indole were synthesized and their relative activity as topoisomerase I inhibitors determined. None of these heterocyclic analogues were effective in significantly inhibiting cleavable-complex formation in the presence of DNA and topoisomerase I, suggesting a high degree of structural specificity associated with the interaction of these substituted benzimidazoles with the enzyme or the enzyme-DNA complex. In evaluating their cytotoxicity, these new topoisomerase I poisons also exhibited no significant cross-resistance against cell lines that express camptothecin-resistant topoisomerase I.