10.1021/ja01332a059
The study investigates the behavior of mixed halogenated phenols and cresols in the Zincke method of nitration. Various mixed halogenated phenols, such as 2-bromo-4-chlorophenol, 2-chloro-4-bromophenol, and their derivatives, were prepared and subjected to nitration. The researchers observed that when bromine occupies both ortho and para positions in a phenol or cresol, isomeric mononitro compounds can be formed. For the first time, it was shown that a phenol with hydrogen in one ortho position and bromine in the other can undergo nitration at both positions in the same experiment. Chlorine was found not to be replaceable by the nitro group under the studied conditions. The study also provided further evidence supporting the view that only one acetyl-benzoyl derivative can be prepared from an o-aminophenol regardless of the order of introduction of the acyl radicals.
10.1021/cc100032d
The study presents a novel one-pot multicomponent reaction for the synthesis of tetrahydrobenzo[b][1,4]oxazepine and malonamide derivatives. The reaction involves 2-aminophenols, Meldrum’s acid, and isocyanides, and it proceeds at ambient temperature with good to excellent yields. These chemicals serve to create a new class of substituted malonamide and tetrahydrobenzo[b][1,4]oxazepine derivatives, which are significant in medicinal chemistry due to their potential as ionophores for selective electrodes, liquid-liquid extractants for nuclear waste management, and pharmaceutical compounds with diverse biological activities, including anticancer properties.
10.1002/chem.201502487
The study presents a bioinspired catalytic aerobic oxidative C-H functionalization of primary aliphatic amines, leading to the synthesis of 1,2-disubstituted benzimidazoles, which are significant in drug discovery. The process employs a biomimetic cooperative catalytic system that includes a copper(II) salt (CuBr2) as an electron transfer mediator and an o-iminoquinone organocatalyst (1ox) derived from o-aminophenol (1red), to activate the α-C-H bond of primary amines under ambient air. This atom-economical multistep reaction proceeds under mild conditions and is environmentally friendly, offering a convenient strategy for functionalizing non-activated aliphatic amines. The study also explores the reactions of various primary amine substrates with o-aminoanilines, resulting in the formation of benzimidazoles with different substituents. The synthesized benzimidazoles are important as they are found in pharmaceutical products such as antihypertensives and antihistaminic agents.