607-97-6Relevant articles and documents
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Wislicenus,J.
, p. 187 ()
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Cambillau et al.
, p. 2675,2677 (1978)
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Preparation method of remdesivir intermediate 2-ethyl-1-butanol
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Paragraph 0051-0052, (2020/08/09)
The invention relates to a preparation method of a remdesivir intermediate 2-ethyl-1-butanol. The preparation method comprises a step of substitution reaction, namely a step of carrying out a substitution reaction on alkyl acetoacetate and halogenated ethane under an alkaline condition to obtain alkyl 2-ethyl-3-oxo-butyrate; a step of addition reduction, namely a step of carrying out an addition reduction reaction on the alkyl 2-ethyl-3-oxo-butyate to obtain alkyl 2-ethylbutyrate; a step of reduction, namely a step of subjecting the alkyl 2-ethylbutyrate to a reduction reaction to prepare 2-ethyl-1-butanol (I). According to the preparation method of the remdesivir intermediate 2-ethyl-1-butanol, the alkyl acetoacetate and halogenated ethane serve as main raw materials, the raw materials are simple and easy to obtain, the 2-ethyl-1-butanol (I) is prepared through substitution reaction, addition reduction and reduction reaction, the process is simple, economical and environmentally friendly, the product is convenient to obtain, and industrial production of remdesivir bulk drugs is facilitated.
Asymmetric Aza-Wacker-Type Cyclization of N-Ts Hydrazine-Tethered Tetrasubstituted Olefins: Synthesis of Pyrazolines Bearing One Quaternary or Two Vicinal Stereocenters
Kou, Xuezhen,Shao, Qihang,Ye, Chenghao,Yang, Guoqiang,Zhang, Wanbin
supporting information, p. 7587 - 7597 (2018/06/04)
We have developed an asymmetric aza-Wacker-type cyclization of N-Ts hydrazine-tethered tetrasubstituted olefins, affording optically active pyrazolines bearing chiral tetrasubstituted carbon stereocenters. This reaction is tolerant to a broad range of substrates under mild reaction conditions, giving the desired chiral products with high enantioselectivities. Generation of two vicinal stereocenters on the C=C double bonds was also achieved with high selectivities, a process which has been rarely studied for Wacker-type reactions. A mechanistic study revealed that this aza-Wacker-type cyclization undergoes a syn-aminopalladation process. It was also found that for substrates bearing two linear alkyl substituents on the outer carbon atom of the olefin, both of which are larger than a methyl group, the alkyl substituent that is cis to the intranucleophilic group participates more readily in β-hydride elimination. When one of the two alkyl substituents on the outer carbon atom of the olefin is a methyl group, β-hydride elimination proceeds selectively at the methylene side, thus both diastereomers can be prepared via switching the configuration of the olefin. Furthermore, the product can be converted to a pharmaceutical compound in high yields over three steps.
Highly crystalline poly(heptazine imides) by mechanochemical synthesis for photooxidation of various organic substrates using an intriguing electron acceptor – Elemental sulfur
Savateev, Aleksandr,Dontsova, Dariya,Kurpil, Bogdan,Antonietti, Markus
, p. 203 - 211 (2017/05/04)
Low-defect potassium poly(heptazine imide) (PHIK-BM) was engineered for application in photocatalytic oxidation of organic substrates. Mechanochemical pretreatment of a mixture of 5-aminotetrazole in LiCl/KCl eutectics using high-energy ball milling afforded a highly homogeneous mixture that, upon sequential thermolysis at 600?°C, gave nanosized particles of PHIK–BM. The photocatalytic activity of the free-standing PHIK–BM plates was assessed in the oxidation of benzyl alcohol to benzaldehyde under visible light irradiation using elemental sulfur as an electron acceptor. Both quantitative conversion (>99%) of benzyl alcohol and selectivity (>98%) with respect to benzaldehyde were achieved. The developed method was extended to aliphatic alcohol oxidation coupled with multicomponent Hantzsch 1,4-dihydropyridine synthesis. These 1,4-dihydropyridines were also photocatalytically oxidized by PHIK–BM to the corresponding substituted pyridines, with very good yields and under mild metal-free conditions.
