- Preparation method of 5-bromo-2-chlorobenzoic acid
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The invention relates to a preparation method of 5-bromo-2-chlorobenzoic acid. The preparation method comprises the following steps: taking 2-chlorobenzoic acid as an initial reactant, sequentially carrying out chlorination, acylation and cyclization reactions to obtain a protective group o-chlorobenzoic acid (a compound represented by formula III), and sequentially carrying out bromination and hydrolysis to obtain 5-bromo-2-chlorobenzoic acid. The reaction conditions are mild, and the safety of the preparation process is improved. The yield of the prepared product can reach 75% or above, thepurity can reach 99% or above, and the purity and yield are much higher than those of an existing preparation method. Meanwhile, the preparation method is simple in process step, the product is easy to purify, 5-bromo-2-chlorobenzoic acid can be synthesized on a large scale, and the preparation method has a good industrial development prospect.
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Paragraph 0016; 0032-0035; 0041-0044; 0049-0053
(2020/11/26)
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- Palladium-catalyzed electrophilic C–H fluorination of arenes using oxazoline as a removable directing group
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Dimethyloxazoline was rationally designed to act as a removable ortho-directing group (DG) for the palladium-catalyzed C–H electrophilic fluorination of arenes. Using NFSI as the fluorinating agent, and Pd(II), Ag(I) catalytic system, electrophilic C(sp2–H) ortho-fluorination took place on a variety of aryl substrates to afford the corresponding mono- and di-fluorinated products.
- Gutierrez, David A.,Lee, Wan-Chen Cindy,Shen, Yuning,Li, Jie Jack
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supporting information
p. 5372 - 5376
(2016/11/11)
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- Directed functionalization of halophenyl-2-oxazolines with TMPMgCl?LiCl
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A variety of difunctionalized aryl-2-oxazolines were prepared from the reaction of halophenyl-2-oxazolines and TMPMgCl?LiCl to give an organomagnesium reagent, which was then treated with various electrophiles. The metalation step takes place under mild conditions, and this process al-lows for the isolation of the desired products in good yields. No isomeric or other benzyne-derived products were detected. The influence of the halogen substituents on the acidity of the aromatic hydrogen atoms was evaluated by using density functional theory (DFT) calculations.
- Batista, Joo H. C.,Santos, Fernanda M. Dos,Bozzini, Leandro A.,Vessecchi, Ricardo,Oliveira, Alfredo R. M.,Clososki, Giuliano C.
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p. 967 - 977
(2015/02/19)
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- A novel and direct synthesis of 1,3,4-oxadiazoles or oxazolines from carboxylic acids using cyanuric chloride/indium
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Direct synthesis of various oxazolines and 1,3,4-oxadiazoles from carboxylic acids was achieved using cyanuric chloride/indium under very mild conditions.
- Kangani, Cyrous O.,Day, Billy W.
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experimental part
p. 5332 - 5335
(2009/12/06)
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- Facile Syntheses of Oxazolines and Thiazolines with N-Acylbenzotriazoles under Microwave Irradiation
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Microwave reactions of 2-amino-2-methyl-1-propanol (2) or 2-aminoethanethiol hydrochloride (4) with readily available N-acylbenzotriazoles 1a-j in the presence of SOCl2 produced 2-substituted 2-oxazolines 3a-j in 84-98% yields and 2-substituted
- Katritzky, Alan R.,Cai, Chunming,Suzuki, Kazuyuki,Singh, Sandeep K.
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p. 811 - 814
(2007/10/03)
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