7693-52-9Relevant articles and documents
Preparation method of eltrombopag intermediate and preparation method of eltrombopag diethanolamine salt
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Paragraph 0038; 0043-0044, (2021/06/22)
The invention provides a preparation method of an eltrombopag intermediate and a preparation method of eltrombopag diethanolamine salt, and relates to the technical field of medicinal chemistry. According to the preparation method of the eltrombopag intermediate, p-bromophenol is taken as a raw material, and the problem of poor selectivity of nitration reaction is solved. After iodination, the coupling reaction yield of the intermediate compound as shown in a formula (I) and phenylboronic acid is high. Subsequently reduction reaction is carried out, the debromination reaction is complete, the yield is 90% or more, the refining is simpler, and the synthesis yield of the compound of the formula (I) is higher and the operation is simple. Through the improvement, the yield of the key compound shown as the formula (I) is relatively high, the subsequent treatment operation is simple, the process is easy for amplified production, the yield of the whole synthesis process of the eltrombopag diethanolamine salt is 48.1%, the operation is simple, less three wastes are generated, and the synthesis process is suitable for amplified production.
A convenient and efficient H2SO4-promoted regioselective monobromination of phenol derivatives using N-bromosuccinimide
Wu, Yong-Qi,Lu, Hai-Jia,Zhao, Wen-Ting,Zhao, Hong-Yi,Lin, Zi-Yun,Zhang, Dong-Feng,Huang, Hai-Hong
supporting information, p. 813 - 822 (2020/02/15)
A convenient, rapid H2SO4-promoted regioselective monobromination reaction with N-bromosuccinimide was developed. The desired para-monobrominated or ortho-monobrominated products of phenol derivatives were obtained in good to excellent yields with high selectivity. Regioselective chlorination and iodination were also achieved in the presence of H2SO4 using N-chlorosuccinimide and N-iodosuccinimide, respectively.
Stepwise mechanism for the bromination of arenes by a hypervalent iodine reagent
Arrieta, Ana,Cossío, Fernando P.,Granados, Albert,Shafir, Alexandr,Vallribera, Adelina
, p. 2142 - 2150 (2020/03/11)
A mild, metal-free bromination method of arenes has been developed using the combination of bis(trifluoroacetoxy)iodobencene and trimethylsilyl bromide. In situ-formed dibromo(phenyl)-λ3-iodane (PhIBr2) is proposed as the reactive intermediate. This methodology using PIFA/TMSBr has been applied with success to a great number of substrates (25 examples). The treatment of mono-substituted activated arenes led to para-brominated products (2u-z) in excellent 83-96% yields. Density functional theory calculations indicate a stepwise mechanism involving a double bromine addition followed by a type II dyotropic reaction with concomitant re-aromatization of the six-membered ring.