2687-43-6Relevant articles and documents
Synthesis and stereoisomerization of 2-(1-alkoxyimino-2,2,2-trifluoroethyl) -5-trimethylsilylfurans
Melnik,Vorona,Veinberg,Popelis,Ignatovich,Lukevics
, p. 718 - 721 (2005)
2-(1-Alkoxyimino-2,2,2-trifluoroethyl)-5-trimethylsilylfurans were synthesized by the condensation of 2-(trifluoroacetyl)-5-trimethylsilylfuran with alkoxyamines. According to 1H and 19F NMR spectroscopic data, the alkoxyimino group in the E-isomers descreens the H-3 and H-4 protons of the furan ring more strongly than in the Z-isomers, shifting their signals downfield. The fluorine atoms of the α-trifluoromethyl group in the Z-isomer are characterized by a downfield shift in relation to the E-isomer. 2005 Springer Science+Business Media, Inc.
Preparation method of benzyloxyamine hydrochloride
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Paragraph 0059-0061; 0064, (2021/04/14)
The invention discloses a preparation method of benzyloxyamine hydrochloride. The preparation method comprises the following steps: (1) dispersing ketoxime 2 and alkali metal hydroxide into a mixed solvent of dimethylacetamide and water at the temperature of 50-55 DEG C and the stirring speed of 100-120 rpm; (2) dropwise adding a benzyl halide compound 1 into a dispersion body obtained in the step (1), reacting for 130-140 minutes at the temperature of 60-65 DEG C after dropwise adding is completed, then cooling to room temperature, adding water, extracting by using normal hexane, and distilling an organic phase under reduced pressure to obtain a product 3; and (3) adding the product 3 obtained in the step (2) into a mixed solution of methanol and a hydrochloric acid solution with the mass concentration of 38% , reacting for 200-220 minutes at the temperature of 35-40 DEG C and at the stirring speed of 80-100 rpm, distilling under reduced pressure until a solid is separated out, cooling to room temperature, washing the solid with petroleum ether, and drying to obtain the target product 4-benzyloxyamine hydrochloride. According to the preparation method, the total yield can reach 95% or above, and the product purity can reach 99% or above.
Vinylogous Aza-Michael Addition of Urea Derivatives with p-Quinone Methides Followed by Oxidative Dearomative Cyclization: Approach to Spiroimidazolidinone Derivatives
Kaur, Navpreet,Singh, Priyanka,Banerjee, Prabal
supporting information, p. 2813 - 2824 (2021/04/21)
Herein, we report an efficient protocol for the synthesis of spiro-imidazolidinone-cyclohexadienones from p-quinone methides (p-QMs) and dialkyloxy ureas under mild conditions. The strategy follows a two-step process involving an initial vinylogous conjugate addition of urea derivatives to p-QMs, followed by oxidative dearomative cyclization of open-chain product to the projected spiro-imidazolidinones. This protocol exhibits good functional group tolerance and provides a straightforward method to access spiro-imidazolidinone-cyclohexadienones. In follow-up chemistry, we have shown the debenzylation of spiroimidazolidinones to give N-hydroxycyclic ureas. (Figure presented.).
