24265-23-4Relevant articles and documents
Development of an efficient process for 3,6-dihydro-2h-pyran-4-boronic acid pinacol ester
Xue, Feng,Zhu, Yong,Li, Chang-Gong
, p. 1654 - 1659 (2015)
An efficient process for the synthesis of 3,6-dihydro-2H-pyran-4-boronic acid pinacol ester has been developed in one-pot manner. Starting from the condensation of 4-tetrahydropyranone with hydrazine hydrate, the subsequent treatment of hydrazone with copper(II) bromide-triethylamine and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) conveniently gave 4-bromo-3,6-dihydro-2H-pyran, which was then conducted through palladium-catalyzed borylation to afford the desired product using a low loading of a Pd catalyst.
Preparation method of heteroatom-containing cyclohexene halide
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Paragraph 0039-0041, (2019/12/25)
The invention discloses a preparation method of a heteroatom-containing cyclohexene halide, belonging to the field of synthesis of fine chemical intermediates. According to the preparation method, cyclohexanone containing heteroatoms is used as a raw material, and gem-dihalide or alkenyl halide is mainly generated in a halogenating reagent; and after an additive is added into organic alkali, and hydrogen halide is removed to generate cyclohexene halide containing heteroatoms. The method is simple in process; the operation of purifying a mixture in traditional methods is avoided; and a productis fully utilized. Under close-to-elimination condition of gem-dibromide, an additive is added to overcome the problem of difficulties in gem-dichloride elimination is by adding, and the purpose of controlling regioselectivity is achieved through steric hindrance of different alkalis.
Method for synthesizing 3, 6-dihydro-2H-pyrazine (thiazine) furan-4-boric acid ester
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Paragraph 0014, (2016/10/31)
The invention discloses a method for synthesizing 3, 6-dihydro-2H-pyrazine (thiazine) furan-4-boric acid ester. According to the method, tetrahydropyrazole (thiazine) furan-4-ketone serves as the raw material, generates hydrazone with p-toluenesulfonhydrazide, then reacts with NBS/organic alkali to generate alkenyl bromide and next forms Grignard reagent with magnesium metal, after the Grignard reagent is formed, boron reagent is added for a reaction, and the 3, 6-dihydro-2H-pyrazine (thiazine) furan-4-boric acid ester is obtained. By means of the method, ultralow temperature, column chromatography and palladium catalyzed coupling in a literature method are avoided, raw materials are easy to obtain, cost is low, conditions are mild, and the method has potential industrial application and amplification prospect.