- Switchable synthesis of cyclic carbamates by carbon dioxide fixation at atmospheric pressure
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The base-promoted switchable synthesis of five- and six-membered cyclic carbamates using atmospheric pressure carbon dioxide as the C1 source was developed. The chemoselectivity of products was simply controlled by changing bases and solvents. The reaction proceeds effectively under mild conditions, affording valuable cyclic carbamates. Experimental results and DFT studies revealed the reaction mechanism.
- Toda, Yasunori,Shishido, Minoru,Aoki, Tatsuya,Sukegawa, Kimiya,Suga, Hiroyuki
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supporting information
p. 6672 - 6675
(2021/07/13)
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- ACID ADDITION SALTS OF SYNTHETIC INTERMEDIATES FOR CARBAPENEM ANTIBIOTICS AND PROCESSES FOR PREPARING THE SAME
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The present invention provides a process for preparing an acid addition salt of a synthetic intermediate for carbapenem antibiotics and a novel acid addition salt of a synthetic intermediate for carbapenem antibiotics obtained from the process. The present invention also provides a process for preparing a carbapenem antibiotic using the acid addition salt. According to the process of the present invention, an acid addition salt of a synthetic intermediate for carbapenem antibiotics can be prepared in a high yield and high purity, without conducting column chromatography. Thus, the process of the present invention can be applied to mass production with an industrial scale. Furthermore, since the acid addition salts have solid forms, they are easy to handle and keep in a manufacturing site.
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Page/Page column 8
(2010/12/26)
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- ACID ADDITION SALTS OF SYNTHETIC INTERMEDIATES FOR CARBAPENEM ANTIBIOTICS AND PROCESSES FOR PREPARING THE SAME
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The present invention provides a process for preparing an acid addition salt of a synthetic intermediate for carbapenem antibiotics and a novel acid addition salt of a synthetic intermediate for carbapenem antibiotics obtained from the process. The present invention also provides a process for preparing a carbapenem antibiotic using the acid addition salt. According to the process of the present invention, an acid addition salt of a synthetic intermediate for carbapenem antibiotics can be prepared in a high yield and high purity, without conducting column chromatography. Thus, the process of the present invention can be applied to mass production with an industrial scale. Furthermore, since the acid addition salts have solid forms, they are easy to handle and keep in a manufacturing site.
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Page/Page column 19
(2009/04/25)
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- 2-ARYLMETHYLAZETIDINE CARBAPENEM DERIVATIVES AND PREPARATION THEREOF
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A 2-arylmethylazetidine carbapenem derivative of formula ( I ) or a pharmaceutically acceptable salt thereof exhibits a wide spectrum of antibacterial activities against Gram-positive and Gram-negative bacteria and excellent antibacterial activities against resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) and quinolone-resistant strains (QRS).
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Page/Page column 9; 11
(2008/06/13)
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- Preparation of Trimethylsilyl Ethers of 3-Azetidinols . Scope and Limitations
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Preparation of the trimethylsilyl ethers of 1-alkyl-3-azetidinols from-non-hindered primary amines and epichlorhydrin by conversion of the intermediate 1-(alkylamino)-3-chloro-2-propanols to their trimethylsilylethers by either N-(trimethylsilyl)acetamide or by 1-(trimethylsilyl)imidazole followed by ring closure in acetonitrile is described.This sequence of reactions fails for aromatic amines, but appears to be general for all primary aliphatic amines, although the condensation of hindered amines with epichlorhydrin occurs slowly.Several novel azetidinols, in which the N-alkyl substituent insefl contains a second heterocyclic system, are reported.In addition, the pKA's of several m- and p-substituted 1-benzylazetidinols correlates well with the Hammett equation.
- Higgins, Robert H.,Watson, Monique R.,Faircloth, William J.,Eaton, Quentin L.,Jenkins, Harvey
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p. 383 - 387
(2007/10/02)
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- Preparation of 3-Azetidinols with Non-Bulky 1-Alkyl Substituents
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Cyclization of either the tetrahydropyranyl or trimethylsilyl ether of 1-(alkylamino)-3-chloro-2-propanols 1 followed by cleavage of the azetidinyl ether provides a general method for the preparation of 1-alkyl-3-azetidinols.Unhindered amines provide a more facile preparation of derivatives of 1, or its ethers, than do hindered amines, while hindered derivatives of 1 undergo more facile ring closure.
- Higgins, Robert H.,Eaton, Quentin L.,Worth, Leroy,Peterson, Myra V.
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p. 255 - 259
(2007/10/02)
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