97-52-9Relevant articles and documents
A green and recyclable ligand-free copper (I) catalysis system for amination of halonitrobenzenes in aqueous ammonia solution
Li, Yan,Shi, Ruhui,Lin, Weiwei,Cheng, Haiyang,Zhang, Chao,Arai, Masahiko,Zhao, Fengyu
, (2019/06/18)
The amination of halonitrobenzenes is an important reaction to produce the corresponding nitroanilines. Direct amination of p-chloronitrobenzene (p-CNB) to p-nitroaniline (p-NAN) with aqueous NH3 solution was investigated over various transition metal salts in the absence of ligand, inorganic base and organic solvent. It was found that CuI is the most effective catalyst with respect to p-CNB conversion, p-NAN selectivity (≈ 100%) and the post-reaction separation and recycling. A high p-NAN yield of 97% could be obtained at 200 °C in 6.5 h with molar ratios of NH3/p-CNB and CuI/p-CNB of 21 and 0.1, respectively. A possible reaction mechanism was proposed, in which NH3 was not only a substrate but also a ligand to coordinate with CuI and formed a water-soluble Cu complex, and then it started the catalytic cycle. The influence of reaction variables such as NH3 concentration, CuI concentration, temperature and time on the p-CNB conversion and the p-NAN selectivity was examined. At room temperature the desired product of p-NAN is insoluble in water but the Cu complex catalyst is water-soluble and so the aqueous phase including the catalyst and NH3 can be easily separated and reused for the subsequent reaction runs. The green and sustainable system is effective for the conversion of diverse halonitrobenzenes to nitroanilines.
Process for preparing red-B preparation method
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Paragraph 0039, (2017/12/02)
The invention relates to a preparation method for a red base B. A formylation reaction is performed on o-aminoanisole and formic acid at 80-102 DEG C on the condition that acylation reaction solvent exists, and filtration is performed to obtain o-formamide anisole after the formylation reaction is completed; the o-formamide anisole is added into a sulfuric acid solution, nitric acid is added into a reaction system to perform a nitration reaction when the temperature of the reaction system is controlled at 0-70 DEG C, and filtration is performed to obtain methoxyl-4-nitroformanilide after the nitration reaction is completed; a hydrolysis reaction is performed on the methoxyl-4-nitroformanilide on the condition that the sulfuric acid and water exist at 80-120 DEG C, after the hydrolysis reaction is completed, separation is performed, the pH value is regulated to 6-7 with sodium carbonate, and then filtration is performed to obtain the red base B. According to the preparation method, the produce yield is high, the cost is low, the quality is good, by-products are less, waste water generated in the production process of the red base B is greatly reduced, the clean production requirement is met, operation is easy and convenient, and industrialization is facilitated.
Steric-Hindrance-Induced Regio- and Chemoselective Oxidation of Aromatic Amines
Patil, Vilas Venunath,Shankarling, Ganapati Subray
, p. 7876 - 7883 (2015/09/01)
Unusual regio- and chemoselective oxidation of aromatic amines hindered with ortho substituents (except -NH2, -NHCH3, and -OH) to the corresponding nitro compounds is described by use of nonanebis(peroxoic acid). The mechanistic investigation for selective oxidation of amines ortho-substituted with -NH2 or -OH showed the involvement of H-bonding between the ortho hydrogen of the adjacent -XH group (where X = NH, NR, or O) and an oxygen atom from the diperoxy acid. Various mono- and diamines are oxidized into corresponding mononitro derivatives in high yield and purity without employing any protection strategies. The protocol was also found to successful on the gram scale.
