- Preparation method of edoxaban intermediate
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The invention discloses a preparation method of edoxaban intermediate (1S, 3R, 4R)-3-tert-butoxycarbonylamino-4-hydroxy-cyclohexanecarboxylic acid. According to the preparation method, 3-amino-4-hydroxy-cyclohexane carboxylate represented by formula IV is taken as a raw material, protective reaction with amino protection groups is carried out so as to obtain 3-tert-butoxycarbonylamino-4-hydroxy-cyclohexane carboxylate represented by formula V, enzyme catalyzed esterification resolution reaction is carried out so as to obtain optically pure (1S, 3R, 4R)-3-tert-butoxycarbonylamino-4-hydroxy-cyclohexane carboxylate represented by formula VII, and at last lithium hydroxide hydrolysis is adopted so as to obtain the (1S, 3R, 4R)-3-tert-butoxycarbonylamino-4-hydroxy-cyclohexanecarboxylic acid represented by formula VI. The preparation method possesses following advantages: operation is simple, the preparation method is green, is friendly to the environment, and is high in selectivity and lowin cost, large scale industrialized production can be realized, and it is convenient for industrial popularization.
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- Photochemical decomposition of t-butylperoxyacetals
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The decomposition of peroxides in the solid phase by UV radiation was investigated.It was shown that the decomposition of peroxides results in the formation of unstable alkoxy radicals, which decompose at C-C or C-H bonds, giving rise to alkyl radicals.An appreciable similarity between the final products of the decomposition of solid peroxides by UV radiation and the products of the thermolysis of the same peroxides was established, which led to the hypothesis that there is some similarity between the mechanism of the decomposition of the peroxides.
- Turovskii, A. A.,Luk'yanenko, L. V.,Kucher, R. V.,Petrenko, V. V.
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p. 1157 - 1160
(2007/10/02)
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- General Syntheses of 6- and 7-Carbomethoxy-trans-1-heteradecalins and 6- and 7-Carbomethoxy-trans-2-heteradecalins
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Two routes to all of the title compounds in the oxa and aza series have been studied.The most general path, involving a cyclohexene oxide intermediate, was not successful becauase of difficulty in separating regioisomers.Allylation of 4-carbomethoxycyclohexanone (11) followed by reduction produced the required trans-disubstituted allyl alcohols, which were converted to all of the desired 6-carbomethoxy-trans-1-heteradecalins.The allyl ketones were subjected to a homologation-side chain contraction sequence to produce the 6-carbomethoxy-trans-2-heteradecalins.Allylation of 3-carbomethoxycyclohexanone (12) was not regioselective, but all four product isomers were characterized.The desired 5-carbomethoxy-2-allylcyclohexanone isomers (27 and 28) were converted to the 7-carbomethoxy-trans-decalins by similar series of reactions
- Hirsch, Jerry A.,Truc, Vu Chi
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p. 2218 - 2227
(2007/10/02)
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