39078-05-2

Upstream product

• 98-88-4 benzoyl chloride 
• 6315-89-5 3,4-dimethoxyaniline 
• 33904-01-7 4-isocyano-1,2-dimethoxybenzene 
• 100-52-7 benzaldehyde 
• 611-73-4 Benzoylformic acid 
• 709-09-1 3,4-dimethoxynitrobenzene 
• 67-56-1 methanol 
• 106501-69-3 N-(4,4-dimethoxycyclohexa-2,5-dien-1-ylidene)benzamide 

Downstream Products

• 156086-03-2 5,6-dimethoxy-2-phenyl-1,3-benzothiazole 
• 117559-80-5 N-benzoyl-3-methoxy-p-benzoquinone imine dimethyl ketal 

Relevant academic research and scientific papers

Iron-Catalyzed Regioselective Synthesis of 2-Arylbenzoxazoles and 2-Arylbenzothiazoles via Alternative Reaction Pathways

A one-pot regioselective method for the preparation of 2-arylbenzoxazoles from N-arylbenzamides has been developed using iron(III)-catalyzed bromination of the aryl ring, followed by copper(I)-catalyzed O-cyclization with the benzamide side chain. In contrast, reaction of N-arylthiobenzamides with N-bromosuccinimide and iron triflimide led directly to the isolation of the corresponding 2-arylbenzothiazoles via intramolecular C–S bond formation. Mechanistic and control experiments suggest that in this case, bromination occurs at the sulfur atom, resulting in a reactive intermediate that can undergo electrophilic aromatic substitution and S-cyclization. The scope of both processes was explored yielding a range of structural analogues, including a pharmaceutically active compound for the treatment of Duchenne muscular dystrophy and an affinity agent of the amyloid-beta protein in Alzheimer's disease.

Selective, Catalytic, and Metal-Free Coupling of Electron-Rich Phenols and Anilides Using Molecular Oxygen as Terminal Oxidant

Selective oxidative homo- and cross-coupling of electron-rich phenols and anilides was developed using nitrosonium tetrafluoroborate as a catalyst. Oxidative coupling of phenols revealed unusual selectivities, which translated into the unprecedented synthesis of inverse Pummerer-type ketones. Mechanistic studies suggest that oxidative coupling of phenols and anilides shares a common pathway via homolytical heteroatom-hydrogen bond cleavage. Nitrosonium salt catalysis was applied for cross-dehydrogenative coupling initiated by generation of heteroatom-centered radicals.

Reagent- and Metal-Free Anodic C?C Cross-Coupling of Aniline Derivatives

The dehydrogenative cross-coupling of aniline derivatives to 2,2′-diaminobiaryls is reported. The oxidation is carried out electrochemically, which avoids the use of metals and reagents. A large variety of biphenyldiamines were thus prepared. The best results were obtained when glassy carbon was used as the anode material. The electrosynthetic reaction is easily performed in an undivided cell at slightly elevated temperature. In addition, common amine protecting groups based on carboxylic acids were employed that can be selectively removed under mild conditions after the cross-coupling, which provides quick and efficient access to important building blocks featuring free amine moieties.

Aerobic oxidative homocoupling reaction of anilides using heterogeneous metal catalysts

We have developed a heterogeneous catalytic oxidative homocoupling reaction of dimethoxyanilides under an oxygen atmosphere. The resulting homo-dimers are useful for the construction of heterocycles, demonstrating the potential of heterogeneous metal catalysts.

Copper-catalyzed synthesis of arylcarboxamides from aldehydes and isocyanides: The isocyano group as an N1 synthon

An interesting radical coupling reaction of aromatic aldehydes with isocyanides was disclosed for the synthesis of amides catalyzed by copper. According to the experimental results and mechanistic study, the isocyano group acted as an N1 synthon rather than exhibiting the carbene-like reactivity, exploiting a new reactivity profile of isocyanides.

Catalyst-Free Singlet Oxygen-Promoted Decarboxylative Amidation of α-Keto Acids with Free Amines

A novel catalyst-free decarboxylative amidation of α-keto acids with amines under mild conditions has been developed. Advantages of the new protocol include avoidance of metal catalysts and high levels of functional group tolerance. In addition, the reaction can be scaled up and shows high chemoselectivity. Preliminary mechanistic studies suggest that singlet oxygen, generated from oxygen under irradiation, is the key promoter for this catalyst-free transformation.

Thermally induced cyclization of electron-rich N-arylthiobenzamides to benzothiazoles

Heating N-(2-methoxyphenyl)benzenecarbothioamides in refluxing nitrobenzene for 24 hours gives the corresponding benzothiazoles with intramolecular ipso substitution of the ortho-methoxy substituent. The thermal cyclization of various other N-arylthiobenzamides is also explored. Georg Thieme Verlag Stuttgart · New York.

Conversion of thiobenzamides to benzothiazoles via intramolecular cyclization of the aryl radical cation

A new and general method has been developed for the intramolecular cyclization of thiobenzamides to benzothiazoles via aryl radical cations as reactive intermediates. The method utilizes phenyliodine(III) bis(trifluoroacetate) (PIFA) in trifluoroethanol or cerium ammonium nitrate (CAN) in aqueous acetonitrile at room temperature to effect cyclization within 30 min in moderate yields.

Novel applications of hypervalent iodine: PIFA mediated synthesis of benzo[c]phenanthiridines and benzo[c]phenanthridinones

A short and efficient access to benzo[c]phenanthridines and phenanthridinones is achieved by the action of phenyliodine(III)-bis(trifluoroacetate) (PIFA) on properly substituted benzylnaphthylamines and naphthylbenzamides, respectively. This reagent promotes a non-phenolic oxidative biaryl coupling process, the key step of the synthesis. A study of the electronic and steric requirements of the substrates is carried out since, in some cases, dimerization processes prevail over intramolecular cyclization. A mechanistic proposal is also included.

The Chemisty of Acylated Quinone Imine Ketals. Nucleophilic and Organolithium Addition Reactions

Acylated quinone imine ketals are readily available via anodic oxidation of p-methoxybenzanilides and p-methoxyacetanilides.These compounds react with a variety of nucleophiles to give the corresponding substituted 2- and/or 3-substituted-4-methoxyanilide