- Efficient synthesis of (S,S)-2,8-diazabicyclo[4.3.0]nonane
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An efficient synthetic route for moxifloxacin chiral intermediate via five steps was established. First, dehydration, N-acylation, and cyclization were combined in one pot to meet the industrial requirement. Then relatively low hydrogen pressure was employed in the catalytic hydrogenation reaction with high yield. Isopropanol/water system was used in resolution, which guaranteed high yield and perfect optical purity. The racemic process conducted by manganese dioxide and Pd/C successfully converted the undesired enantiomer into the racemate and hence the total yield increased remarkably. Furthermore, mild hydrogen transfer catalytic hydrogenation method was utilized in debenzylation process instead of high-pressure hydrogenation. Total yield of 39.0% was achieved, which was much higher than that of 29.0% in literature.
- Chen, Shipeng,Liu, Dongqi,Si, Leilei,Chen, Ligong,Yan, Xilong
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- Highly efficient racemisation of a key intermediate of the antibiotic moxifloxacin
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N-Chlorination by sodium dichloroisocyanurate and dehydrochlorination by TEA, followed by hydrogenation, allowed (1R,6S)-8-benzyl-7,9-dioxo-2,8- diazabicyclo[4.3.0]nonane to be quantitatively racemised and the resulting trans-free cis racemate to be recycled into the resolution process to yield (1S,6R)-8-benzyl-7,9-dioxo-2,8-diazabicyclo[4.3.0]nonane, a key intermediate of moxifloxacin.
- Pallavicini, Marco,Bolchi, Cristiano,Fumagalli, Laura,Piccolo, Oreste,Valoti, Ermanno
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- A 6 - benzyl - 5, 7 - dioxo - 1, 2, 3, 4 - tetrahydro - pyrrolo [3, 4 - b] pyridine preparation method
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The invention discloses a preparation method for 6-benzyl-5,7-dioxo-1,2,3,4-tetrahydro-pyrrolo-[3,4-b] pyridine. The preparation method comprises the steps that an oxidative dehydrogenation reaction is performed on (1R,6S)-cis 8-benzyl-7,9-dioxo-2,8-diaza
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Paragraph 0022; 0029; 0030; 0031; 0032; 0033
(2017/07/12)
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- METHOD FOR PRODUCTION OF (S,S)-6-BENZYLOCTAHYDRO-1H-PYRROLO[3,4-B]PYRIDINE, AN INTERMEDIATE OF AZABICYCLO PYRIDINE DERIVATIVES
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The present invention relates to a cost effective process for the production of (S,S)-6- benzyloctahydro-1H-pyrrolo[3,4-b]pyridine of Formula (I), an important intermediate for the manufacture of azabicyclo pyridine derivatives.
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Page/Page column 25
(2014/07/08)
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- Racemisation of (1R, 6S)-8-benzyl-7,9-dioxo-2,8-diazabicyclo[4.3.0]nonane using halogenated solvent in basic medium
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A simple, highly rapid, efficient and eco friendly process for Racemisation of (1R, 6S)-8-benzyl-7,9-dioxo-2,8-diazabicyclo[4.3.0] nonane in various halogenated solvents has been carried out as a base catalysed reaction to afford racemic mixture in excellent yields (80-95%) at temperature of or below 40°C. The base catalysed racemisation in halogenated solvent has an advantage of simple workup procedure, and use of less volume of halogenated solvent irrespective of type of solvent used in the reaction system.
- Bhavsar, Jigar,Bhashkar, Bhuwan,Kumar, Anil
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p. 241 - 246
(2013/06/27)
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