95970-08-4Relevant articles and documents
Preparation method for 2,5-dibromophenol
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, (2019/02/21)
The invention discloses an industrial preparation method for 2,5-dibromophenol. The industrial preparation method for the 2,5-dibromophenol comprises the following steps: using 2-amino-5-nitrobenzenemethyl ether as an initial raw material, and synthesizing the 2,5-dibromophenol through a four-step reaction of performing diazotization bromination, reduction, secondary diazotization bromination anddemethylation. The obtained 2,5-dibromophenol is a black solid, the purity is 97.5%, a raw material conversion rate in each step reaches 100% respectively, and a total yield of the whole process reaches 34%.
Transition-metal-free decarboxylative bromination of aromatic carboxylic acids
Quibell, Jacob M.,Perry, Gregory J. P.,Cannas, Diego M.,Larrosa, Igor
, p. 3860 - 3865 (2018/04/26)
Methods for the conversion of aliphatic acids to alkyl halides have progressed significantly over the past century, however, the analogous decarboxylative bromination of aromatic acids has remained a longstanding challenge. The development of efficient methods for the synthesis of aryl bromides is of great importance as they are versatile reagents in synthesis and are present in many functional molecules. Herein we report a transition metal-free decarboxylative bromination of aromatic acids. The reaction is applicable to many electron-rich aromatic and heteroaromatic acids which have previously proved poor substrates for Hunsdiecker-type reactions. In addition, our preliminary mechanistic study suggests that radical intermediates are not involved in this reaction, which is in contrast to classical Hunsdiecker-type reactivity. Overall, the process demonstrates a useful method for producing valuable reagents from inexpensive and abundant starting materials.
Active Molybdenum-Based Anode for Dehydrogenative Coupling Reactions
Beil, Sebastian B.,Müller, Timo,Sillart, Sydney B.,Franzmann, Peter,Bomm, Alexander,Holtkamp, Michael,Karst, Uwe,Schade, Wolfgang,Waldvogel, Siegfried R.
supporting information, p. 2450 - 2454 (2018/02/09)
A new and powerful active anode system that can be operated in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) has been discovered. In HFIP the molybdenum anode forms a compact, conductive, and electroactive layer of higher-valent molybdenum species. This system can replace powerful but stoichiometrically required MoV reagents for the dehydrogenative coupling of aryls. This electrolytic reaction is more sustainable and allows the conversion of a broad scope of activated arenes.
NOVEL MCH RECEPTOR ANTAGONISTS
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Page/Page column 76, (2008/06/13)
The present invention relates to a melanin concentrating hormone antagonist compound of formula (I): wherein R1, Ra, Rb, R2, L1, R3, R4 and R5 are as defined, or a pharmaceutically acceptable salt, enantiomer, diastereomer or mixture of diasteromers thereof useful in the treatment, obesity and related diseases.
POLYBROMINATED AROMATIC COMPOUNDS. IV. METHOXYDEBROMINATION REACTIONS OF POLYBROMOBENZENES IN PYRIDINE
Shishkin, V. N.,Lapin, K. K.,Tanaseichuk, B. S.,Butin, K. P.
, p. 516 - 522 (2007/10/02)
The rates were measured and the orientation was studied for the methoxydebromination of all polybromobenzenes C6HnBr6-n (n = 0-3) in pyridine at 115 deg C.From comparison of the partial rates of substitution of the bromine atom at various positions of the benzene ring it was found that the activating effect of the bromine atom in relation to the point of nucleophilic attack changes in the order o-Br > m-Br > p-Br, and the directing selectivity of the bromine is low (compared with fluorine in the methoxydefluorination of polyfluorobenzenes) and increases with decrease in the number of bromine atoms in the aromatic ring of the substrate.
POLYBROMINATED AROMATIC COMPOUNDS. III. SYNTHESIS OF BROMINE-SUBSTITUTED ANISOLES
Shishkin, V. N.,Tanaseichuk, B. S.,Lapin, K. K.,Ivkina, A. A.,Butin, K. P.
, p. 2357 - 2366 (2007/10/02)
Reliable methods were developed for the synthesis of di-, tri-, and tetrabromoanisoles, and all the possible individual isomers were synthesized.The structures of the isomers were proved by alternative synthesis and spectral methods (PMR, IR).It was shown that the published data are incorrect in a number of cases; either the final product was assigned the incorrect structure, or the published methods led to mixture of the various isomers.
