63331-67-9Relevant academic research and scientific papers
Technology for synthesizing N-substituted pyrazol-4-borate
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Paragraph 0016; 0017, (2016/12/01)
The invention discloses a technology for synthesizing N-substituted pyrazol-4-borate. The technology comprises the following steps: taking 2-bromomalonaldehyde as a raw material; firstly, causing the 2-bromomalonaldehyde and triethyl orthoformate to react to obtain acetal; transforming bromine into bi(diisopropylamine)boron; then, carrying out a condensation reaction on the bi(diisopropylamine)boron and substituted hydrazine; and finally, causing an obtained product to react with different glycols to obtain the N-substituted pyrazol-4-borate. The method has the advantage of easy obtaining of raw materials, simple synthesis steps and high reaction yield and is suitable for industrialization amplification production.
Claisen Orthoester Rearrangement in the Direct Preparation of Z-Isositsirikine and Z-Geissoschizine Derivatives Possessing the Right Oxidation State at C-17
Lounasmaa, Mauri,Hanhinen, Pirjo,Jokela, Reija
, p. 8623 - 8648 (2007/10/02)
The Claisen orthoester rearrangement utilizing allylic alcohol 1 (or 2) and trimethyl 3-methoxyorthopropionate 13a leads to Z-isositsirikine derivatives 21a-22a (or 23a-24a) possessing one RO-function at C-17.In the cases of trialkyl 3,3-dialkoxyorthopropionates , the intermediate ketene acetals 25a,b do not rearrange according to the Claisen mechanism to form compounds 26a,b and/or possessing two two RO-functions at C-17.Syntheses of the intermediate orthoesters, trimethyl 3-methoxyorthopropionate 13a, trimethyl 3,3-dimethoxyorthopropionate 14a, trimethyl trans-3-methoxyorthoacrylate 20c, and triethyl 3,3-diethoxyorthopropionate 14b are described.
