- A facile synthesis of (tert-alkoxy)amines
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Tertiary alcohols react with stoichiometric BF3?Et 2O and N-hydroxyphthalimide to yield N-alkoxyphthalimides. Subsequent hydrazinolyses afford the title compounds.
- Palandoken, Hasan,Bocian, Chris M.,McCombs, Michelle R.,Nantz, Michael H.
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- Design, synthesis and evaluation of wound healing activity for β-sitosterols derivatives as potent Na+/K+-ATPase inhibitors
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β-Sitosterols, is a common steroid that can be identified in a variety of plants and their efficacy in promoting wound healing has been demonstrated. Na+/K+-ATPase, more than a pump, its signal transduction function for involvement in cell growth regulation attracts widespread concern. The Na+/K+-ATPase/Src receptor complex can serve as a receptor involved in multiple signaling pathways including promoting wound healing pathways. To finding potent accelerating wound healing small molecular, we choose the high inhibitory activity of Na+/K+-ATPase and non-cardiotoxic natural compound, β-sitosterol as the substrate. A series of β-sitosterol derivatives were designed, synthesized and evaluated as potential Na+/K+-ATPase inhibitors. Among them, compounds 31, 47, 49, showed improved inhibitory activity on Na+/K+-ATPase, with IC50 value of 3.0 μM, 3.4 μM, 2.2 μM, which are more potent than β-sitosterol with IC50 7.6 μM. Especially, compound 49 can induce cell proliferation, migration and soluble collagen production in L929 fibroblasts. Compared to model, compound 49 can accelerate wound healing in SD rats. Further studies indicated that 49 can activate the sarcoma (Src), uptake the protein kinase B (Akt), extracellular signal-regulated kinase (ERK) proteins expression in a concentration dependent manner. Finally, binding mode of compound 49 with Na+/K+-ATPase was studied, which provides insights into the determinants of potency and selectivity. These results proved β-stitosterol derivative 49 can serve as an effective inhibitor of Na+/K+-ATPase and potential candidate for accelerating wound healing agents.
- Cui, Shaoyu,Jiang, Hongli,Chen, Lei,Xu, Jian,Sun, Wenzhuo,Sun, Haopeng,Xie, Zijian,Xu, Yunhui,Yang, Fubai,Liu, Wenyuan,Feng, Feng,Qu, Wei
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- Sterol derivatives and its preparation method and application
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The invention discloses a sterol derivative of beta-sitosterol, beta-stigmasterol and cholesterol, and is shown as a formula VI. The invention also discloses a preparation method of the sterol derivative. The invention also discloses application of the sterol derivative to the aspect of preparation of wound healing promoting medicine. By starting from easily obtained natural products, the beta-sitosterol, the beta-stigmasterol and the cholesterol are used as starting raw materials; the synthetic method is simple; better operability and reaction yield are realized. The prepared sterol derivative has the obvious wound healing promoting activity; the multiplication, migration and collagen synthesis capability on L929 mechanocytes is obviously higher than that of the raw material and positive control medicine recombinant human bFGF (basic fibroblast growth factor). Compared with protide type medicine (such as bFGF), the prepared sterol derivative has more diversified dosage forms and medication modes; the reference is provided for the application in the field of wound healing promoting. The formula VI is shown as the accompanying diagram.
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Paragraph 0118-0120
(2019/05/19)
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- O - substituted hydroxylamine hydrochloride and its preparation method (by machine translation)
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The present invention provides a O - substituted hydroxylamine hydrochloride and its preparation, wherein the preparation method comprises the following steps: step S1, to the acetyl hydroximic acid ethyl ester in ethanol solution of adding sodium hydroxide, in addition at the same time instillment halohydrocarbon, chloride or acyl chloride substitution reaction to take place, then added to the water in order to separate out the O - substituted [...]; step S2, the said O - substituted [...] adding hydrochloric acid solution in order to produce reflux reaction O - substituted hydroxylamine hydrochloride. According to the embodiment of the invention of the O - substituted hydroxylamine hydrochloride of the preparation method, high purity of the product can be obtained, and the method is safe, easy to process, the process is simple, and is suitable for industrial production. (by machine translation)
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Paragraph 0072; 0075; 0076
(2018/10/11)
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- On the origins of diastereoselectivity in the alkylation of enolates derived from N-1-(1′-Naphthyl)ethyl-O-tert-butylhydroxamates: Chiral Weinreb amide equivalents
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(Chemical Equation Presented) The stereochemical outcome observed upon alkylation of enolates derived from N-1-(1′-naphthyl)ethyl-O-tert- butylhydroxamates (chiral Weinreb amide equivalents) may be rationalized by a chiral relay mechanism. Deprotonation withKHMDS leads to a nonchelated (Z)-enolate inwhich the oxygen atoms adopt an anti-periplanar conformation. The configuration of the N-1-(1′-naphthyl)ethyl group dictates the conformation of the O-tert-butyl group and the configuration adopted by the adjacent pyramidal nitrogen atom. Highly diastereoselective enolate alkylation then proceeds anti to both the bulky tert-butyl group (sterically driven) and the N-lone pair (stereoelectronically driven).
- Davies, Stephen G.,Goodwin, Christopher J.,Hepworth, David,Roberts, Paul M.,Thomson, James E.
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supporting information; experimental part
p. 1214 - 1227
(2010/04/26)
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- Synthesis of modified Weinreb amides: N-tert-butoxy-N-methylamides as effective acylating agents
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An efficient preparation of N-methyl-O-tert-butylhydroxylamine hydrochloride has been settled, which allowed the synthesis of modified Weinreb amides. Nucleophilic addition of organolithium and Grignard reagents on these N-tert-butoxy-N-methylamides afforded efficiently the corresponding ketones and reduction with DIBAL furnished the corresponding aldehydes in good yields up to 97%.
- Labeeuw, Olivier,Phansavath, Phannarath,Genêt, Jean-Pierre
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p. 7107 - 7110
(2007/10/03)
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