180506-32-5

Upstream product

• 100-46-9 benzylamine 
• 161692-12-2 1-(2-acetoxy-1-oxoethyl)-1-ethoxycarbonylcyclopropane 
• 129306-05-4 ethyl 1-(2-bromoacetyl)cyclopropanecarboxylate 
• 32933-03-2 ethyl 1-acetylcyclopropanecarboxylate 
• 207554-16-3 4-(Benzyl-tert-butoxycarbonyl-amino)-3-oxo-butyric acid ethyl ester 
• 220969-69-7 1-(2-Benzylamino-acetyl)-cyclopropanecarboxylic acid ethyl ester 
• 76315-01-0 N-benzyl-N-(tert-butoxycarbonyl)glycine 
• 129306-04-3 5-benzyl-5-azaspiro[2.4]heptane-4,7-dione 
• 207554-17-4 1-[2-(Benzyl-tert-butoxycarbonyl-amino)-acetyl]-cyclopropanecarboxylic acid ethyl ester 

Downstream Products

• 144282-41-7 (S)-7-amino-5-benzyl-5-azaspiro[2.4]heptan-4-one 
• 144282-35-9 5-benzyl-7(S)-amino-5-azaspiro[2,4]heptane 
• 1432056-70-6 5-benzyl-7(S)-tert-butoxycarbonylamino-5-azaspiro[2,4]heptane 
• 127254-12-0 sitafloxacin 
• 127199-45-5 (7S)-5-azaspiro[2.4]heptan-7-ylcarbamic acid tert-butyl ester 

Relevant academic research and scientific papers

Preparation method of sitafloxacin hydrate

The invention discloses a preparation method of sitafloxacin hydrate. The method comprises the following steps: taking ethyl 4-bromoacetoacetate used as a raw material, enabling ethyl 4-bromoacetoacetate to be fully reacted with 1,2-dibromoethane and preparing the obtained product into a compound II in the presence of carbonyl reduction enzyme; taking the compound II, enabling the compound II to carry out cyclization reaction with benzylamine in a solvent in the presence of cesium carbonate, enabling the obtained product to be reacted with DPPA and preparing a compound IV; reducing nitrine group of the compound IV to prepare a compound V; connecting primary amine group of the compound V with a BOC protection group to obtain a compound VI; reducing the compound VI through Pd/C, enabling theobtained product to be reacted with 8-chlorine-6,7-difluoro-1-[(1R,2s)-2-fluorocyclopropyl]-4-oxo-1,4-dihydroquinoline-3-carboxylic acid ethyl ester to prepare a compound VIII; and carrying out deprotection of the compound VIII to obtain sitafloxacin hydrate. The sitafloxacin hydrate is few in preparation steps, simple in post-treatment and relatively high in yield.

Preparation method for efficiently synthesizing Sitafloxacin midbody (7S)-5-azaspiro[2.4] heptanes-7-phenylbutane

The invention discloses a preparation method for efficiently synthesizing Sitafloxacin midbody (7S)-5-azaspiro[2.4] heptanes-7-phenylbutane. The method comprises the following steps that a first material shown as the accompanying drawing takes a reaction to obtain a second material shown as the accompanying drawing; the second material takes a reaction to obtain a third material shown as the accompanying drawing; the third material takes a reaction to obtain a fourth material shown as the accompanying drawing; the fourth material takes a reaction to obtain a fifth material shown as the accompanying drawing. The preparation method has the advantages that the single compound with a high ee value can be obtained; the unnecessary waste of materials is avoided; the yield is obviously improved; the operation is simple; the industrial application is easy; the production cost is reduced.

An efficient synthesis of a key intermediate of DU-6859a via asymmetric microbial reduction

An efficient synthetic method for the C-7 substituent of DU-6859a (1), which is a new-generation antibacterial quinolone carboxylic acid, was established by utilizing an enantioselective microbial reduction of 5- benzyl-4,7-dioxo-5-azaspiro[2,4]heptane (7) to the corresponding chiral alcohol (8) as the key reaction. This synthetic method was based on use of AIPHOS (Artificial Intelligence for Planning and Handling Organic Synthesis), which is a synthesis design system that generates suitable retrosynthetic routes from the standpoints of both novelty and practicality.