- Functionalized Cyclopropanes as Versatile Intermediates for the Diversity-Oriented Synthesis of γ-Lactones, γ-Lactams and δ-Lactams
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A two-step procedure for the preparation of cyclopropanecarboxaldehyde-1,1-diester from a γ,δ-epoxyester and its synthetic versatility are described herein. The epoxide ring-opening/cyclopropanation process occurs in the presence of Mg(ClO 4) 2under heating, resulting in cyclopropanemethanol-1,1-diester in 65% yield. A mild TEMPO-mediated oxidation of this substrate readily generated the corresponding aldehyde in 75% yield, which was applied in the one-pot synthesis of four cyclopropylidene-γ-lactams and three δ-lactams. In addition, vinylcyclopropanes were obtained through the Wittig reaction of the aldehyde with phosphonium salts and used as precursors for tetrahydrofurans.
- Maximiano, Adrielle P.,Ramos, Giovana S.,Marques, Marcelo V.,Sá, Marcus M.
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- 2 - Oxygen -3 - piperidine carboxylic acid ethyl ester preparation method (by machine translation)
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The invention provides a 2 - oxo - 3 - piperidine carboxylic acid ethyl ester preparation method, comprising the following steps: S1, the malonic acid diethyl ester and alkaline catalyst after mixing, in the 10 - 50 °C dropping acrylonitrile, obtained by reaction of 2 - cyanoethyl malonic acid diethyl ester; S2, will be the 2 - cyanoethyl malonic acid diethyl ester and organic solvent, [...] catalyst in the hydrogen environment, for 75 - 130 °C react under the, recrystallization to obtain the 2 - oxo - 3 - piperidine carboxylic acid ethyl ester. Compared with the prior art, this invention has the following advantages: the present invention provides a 2 - oxo - 3 - piperidine ethyl formate manufacturing method, with raw materials are easy, simple operation, total yield compared with the classic N·F·Albertsm method up to 77% above (improved 20%), so it is very suitable for industrial production. (by machine translation)
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Paragraph 0027; 0028; 0029; 0032; 0033; 0034; 0035-0037
(2018/09/21)
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- Influence of ring size on the outcome of sulfide contraction reactions with thiolactams. Isolation of bicyclic ketene S,N-acetals and thioisomuenchnones
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Reaction between diethyl bromomalonate and 3-phenylpyrrolidine-2-thione yielded a vinylogous urethane by the Eschenmoser sulfide contraction. However, with 3-substituted piperidine-2-thiones, sulfur was retained in the products, and a range of bicyclic heterocycles, including bicyclic ketene S,N-acetals (2-alkylidene-1,3-thiazolidin-4-ones) and stable thioisomuechnones, was isolated. A novel dimeric ketene S,N-acetal was characterised by X-ray crystallography.
- Michael, Joseph P.,De Koning, Charles B.,Van der Westhuyzen, Christiaan W.,Fernandes, Manuel A.
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p. 2055 - 2062
(2007/10/03)
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- N6-Substituted Adenosine Receptor Agonists. Synthesis and Pharmacological Activity as Potent Antinociceptive Agents
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Novel N6-(indol-3-yl)alkyl derivatives of adenosine were synthesized.The adenosine receptor affinity and the antinociceptive activity of these compounds were assessed in binding studies and the phenylbenzoquinone-induced writhing test.Most of these analogues exhibited a potent analgesic activity without side effects.Among them, compound 3c (UP 202-32) bound to A1 (Ki = 110 nM) and A2 (Ki = 350 nM) adenosine receptors in a specific manner since it did not interact with many other receptors, especially opioid binding sites.The antinociceptive activity in the phenylbenzoquinone assay (ED50 = 3.3 mg/kg po) was antagonized by 8-cyclopentyltheophylline, suggesting that an adenosinergic mechanism underlies the analgesic activity observed with this compound.The data obtained with these new N6-substituted adenosine receptor agonists emphasize the interest of such compounds in the treatment of pain.
- Guengoer, Timur,Malabre, Patrice,Teulon, Jean-Marie,Camborde, Francoise,Meignen, Joelle,et al.
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p. 4307 - 4316
(2007/10/02)
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