1159908-25-4

Upstream product

• 117528-59-3 2,4-dichloro-3-cyano-5-fluoro-benzoyl chloride 
• 924-99-2 ethyl 3-(dimethylamino)acrylate 
• 117528-58-2 2,4-dichloro-3-cyano-5-fluorobenzoic acid 
• 1117-37-9 ethyl (E)-3-(dimethylamino)acrylate 

Downstream Products

• 117528-63-9 ethyl 2-(2,4-dichloro-3-cyano-5-fluorobenzoyl)-3-cyclopropylaminoacrylate 
• 195532-12-8 8-Cyano-1-cyclopropyl-7-((1S,6S)-2,8-diazabicyclo[4.3.0]nonan-8-yl)-6-fluoro-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid 

Relevant academic research and scientific papers

METHOD FOR THE HYDROLYSIS OF QUINOLONECARBOXYLIC ESTERS

Quinolonecarboxylic esters of the general formula (II) are hydrolyzed to quinolonecarboxylic acids of the general formula (I): The method comprises the step A): A) reacting compounds of the formula (II) with a mixture comprising acetic acid, sulfuric acid and water In step A), ≥30 to ≤40 mol of acetic acid, ≥0.3 to ≤1 mol of sulfuric acid and ≥0.9 to ≤2.5 mol of water are used per mole of compounds of the formula (II). The method is particularly suitable for the synthesis of the intermediate (I) in the synthesis of pradofloxacin.

Synthesis method of pradofloxacin

The invention relates to a synthesis method of pradofloxacin. According to the method, a cheap and easy-to-obtain compound is taken as a raw material and subjected to chlorination, acylation, nucleophilic substitution, cyclization, hydrolysis and alkylation reactions, and the target product, namely, pradofloxacin, is obtained. The nucleophilic substitution target product beta-substituted amino-alpha-substituted benzoyl acrylate compound has good quality and has the purity of 98% or above and the yield of 80%-90%, and the yield is increased by 10% or above as compared with that in the prior art; the provided ester hydrolysis method and product quality are good, and the reaction yield reaches 93%-98%; organic base is used for replacing conventional inorganic base to serve as a cyclization reaction catalyst, the operation is simple, no pollution is caused, and the cost is substantially reduced; halogenated hydrocarbon is taken as an alkylation solvent, the reaction temperature is the roomtemperature, the reaction is mild and easy to operate, fewer impurities are produced in the alkylation reaction at the temperature of 20-40 DEG C as compared with those produced in the alkylation reaction at the high temperature in the prior art, the yield is high, halogenated hydrocarbon solvents are easy to recycle and reuse, pollution is greatly reduced, and the synthesis method is environmentally friendly.

A novel approach to Finafloxacin hydrochloride (BAY35-3377)

Finafloxacin hydrochloride, an important clinical compound was synthesized by a novel synthetic approach. An active intermediate ethyl 7-chloro-8-cyano-1-cyclopropyl-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylate 19 was prepared by a new route. The chiral (S,S′)-N-Boc 10 was derived from protected pyrrolidine and the absolute stereochemistry was established by X-ray analysis.