- A 5-benzyl -7 (S)-tert-butoxycarbonylamino-5-azaspiro [2,4] heptane preparation method of
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The invention discloses a preparation method for 5-benzyl-7(S)-t-butyloxycarborylamino-5-aza-spiro[2,4]heptane. The method comprises the following steps: reacting benzoylamide acetoacetate as a raw material with 1,2-dichloroethane to obtain 3-cyclopropyl benzoylamide acetoacetate, brominating 3-cyclopropyl benzoylamide acetoacetate by NBS (n-bromosuccinimide) to obtain 1-bromo-3-cyclopropyl benzoylamide acetoacetate, cyclizing under alkaline conditions to obtain 5-benzyl-5-aza-spiro[2,4]heptane-4,7-diketone, further reacting with hydroxylamine hydrochloride to form an oxime compound-4-oxo-5-benzyl-7-oximido-5-aza-spiro[2,4]heptane, reducing by NaBH4 and boron trifluoride diethyl etherate to obtain 5-benzyl-7-amino-5-aza-spiro[2,4]heptane, performing chiral resolution by a resolving agent-L-camphorsulfonic acid to obtain 5-benzyl-7(S)-amino-5-aza-spiro[2,4]heptane, and reacting with di-tert-butyl dicarbonate ester to obtain 5-benzyl-7(S)-t-butyloxycarborylamino-5-aza-spiro[2,4]heptane. According to the method, an intermediate body-carbonyl does not need protection, raw materials are easy to get, a process route is simple, and the method is suitable for industrial production.
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- Halonium-initiated C - O bond formation via umpolung of α-carbon to the carbonyl: Efficient access to 5-amino-3(2 H)-furanones
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Highly efficient C - O bond formation has been developed via carboxylic acid catalyzed reaction of 1-acetylcyclopropanecarboxamides with N-halosuccinimide (NXS), which provides strategically novel and atom-economic access to biologically important 5-amino
- Wei, Ying,Lin, Shaoxia,Xue, Hongxun,Liang, Fushun,Zhao, Baozhong
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scheme or table
p. 712 - 715
(2012/04/10)
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