In the chemical reaction process, reaction time, type of solvent, can easily affect the result of the reaction, thereby determining the yield and properties of the reaction product. An updated downstream synthesis route of 4897-84-1 as follows. Quality Control of Methyl 4-bromobutanoate
To a solution of 2-methyl-3-fluorophenol (5 g, 39.64 mmol) in DMF (60 ml), was added potassium carbonate (6.03 g, 43.61 mmol). After 10 minutes of stirring at room temperature, methyl-4-bromobutyrate (8.31 g, 43.61 mmol) was added. The white suspension was heated at 50¡ãC for 24 hours. After cooling to room temperature, MeOH (50 ml), water (50 ml) and sodium hydroxide 32percent (30 ml) were added. The reaction mixture was heated at 80¡ãC for 30 minutes. After cooling to room temperature, ice (100 g) was added, then HCI 5N was added to pH 3. The solid was filtered, washed with water (3×50 ml) and dried by heating under reduced pressure over P205. To the obtained white powder, polyphosphoric acid (PPA, 100 g) was added, then the mixture was heated at 90¡ãC for 15 minutes. Ice (300 g) was slowly added and the precipitate was filtered, and dried under reduced pressure over P205 to give 6.64 g (86percent) of 8-fluoro-9-methyl-3,4- dihydrobenzo[b]oxepin-5(2H)-one as a yellow solid. LC/MS (m/z, MH+): 195
According to the analysis of related databases, 4897-84-1, the application of this compound in the production field has become more and more popular.
Reference:
Patent; SANOFI; BOUABOULA, Monsif; BROLLO, Maurice; CERTAL, Victor; EL-AHMAD, Youssef; FILOCHE-ROMME, Bruno; HALLEY, Frank; MCCORT, Gary; SCHIO, Laurent; TABART, Michel; TERRIER, Corinne; THOMPSON, Fabienne; (294 pag.)WO2018/91153; (2018); A1;,
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