Synthetic Route of 450-88-4,Some common heterocyclic compound, 450-88-4, name is 1-Bromo-4-fluoro-2-methoxybenzene, molecular formula is C7H6BrFO, traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route.
Reference Example 29 (1) In 15 ml of N, N-dimethylformamide were dissolved 3.94 g of [2-BROMO-5-FLUOROPHENOL] and 1.62 ml of methyl iodide, slowly added thereto was 5.08 g of potassium carbonate under ice-cooling. The mixture was stirred at room temperature for 3 hours. After insoluble matters were removed by filtration, distilled water was added to the filtrate, and the mixture was extracted with diethyl ether and washed with saturated brine. The organic layer was dried over magnesium sulfate and concentrated under reduced pressure. The residue was purified by silica gel column chromatography- (hexane : ethyl acetate=19: [1-9] : 1), to give 4.10 g of [1-BROMO4-FLUORO-2-] methoxybenzene. MS (m/z): 204/206 [(M++L) O] (2) To 7 ml of tetrahydrofuran were added 486 mg of magnesium and trace of iodine, and dropped thereto was a solution of 4.10 g of the compound of the above [(1)] in 16 ml of tetrahydrofuran, to prepare Grignard reagent. To the solution, a solution of 1.96 g of 4-methoxypyridine in 7 ml of tetrahydrofuran was added dropwise under nitrogen atmosphere [AT-60C] or below. Subsequently, a solution of 3.75 g of benzyl chloroformate in 18 ml of tetrahydrofuran was added dropwise, and the mixture was stirred for 3 hours. The temperature of the mixture was raised to room temperature, and 40 ml of a 5% aqueous citric acid solution was added thereto. The mixture was extracted with ethyl acetate and washed with saturated brine. The organic layer was dried and concentrated. The residue was purified by silica gel column chromatography (hexane: ethyl acetate=2: [1-1] : 2), to give 3.15 g of [1-BENZYLOXYCARBONYL-2- (4-FLUORO-2-METHOXYPHENYL)-4-OXO-] 3,4-dihydro-2H-pyridine. MS (m/z): 356 [[M++1]] (3) In a mixed solution of 79 ml of ethanol and 6 ml of tetrahydrofuran was dissolved 3.15 g of the compound of the above (2), and added thereto was 706 mg of sodium borohydride and the mixture was stirred at room temperature for 6 hours. The reaction mixture was concentrated and distilled water was added to the residue. The mixture was extracted with chloroform, and the organic layer was dried and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (chloroform: acetone=19: [1-9] : 1), to give 1.62 g of [1-BENZYLOXYCARBONYL-2- (4-FLUORO-2-] methoxyphenyl)-4-hydroxypiperidine. MS (m/z): 360 [[M++1]] (4) In 20 ml of toluene was dissolved 1.62 g of the compound of the above (3), added thereto was 876 mg of 1, [1′-] carbonyldiimidazole and the mixture was stirred at [60C] for an hour. Added thereto was 1.09 ml of ethanolamine, and the mixture was stirred at [60C] for 6 hours. To the reaction mixture was added distilled water and the mixture was extracted with chloroform. The organic layer was dried and concentrated. The residue was purified by silica gel column chromatography (chloroform: acetone=4: [1-1] : 1), to give 1.81 g of [1-BENZYLOXYCARBONYL-2- (4-FLUORO-2-METHOXYPHENYL)-4- (2-] hydroxyethylaminocarbonyloxy) piperidine. MS (m/z): 447 [[M++L]] [(5)] In 20 ml of methanol was dissolved 1.81 g of the compound of the above (4), and added thereto was 90 mg of 10% palladium-carbon, and the mixture was stirred at room temperature for an hour under hydrogen atmosphere. After insoluble matters were removed by filtration, the filtrate was concentrated. To the residue was added diethyl ether and precipitates were collected by filtration, to give 1.30 g of [2- (4-FLUORO 2-METHOXYPHENYL)-4- (2-] hydroxyethylaminocarbonyloxy) piperidine as shown in Table 134 below.
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 1-Bromo-4-fluoro-2-methoxybenzene, its application will become more common.
Reference:
Patent; TANABE SEIYAKU CO., LTD.; WO2003/99787; (2003); A1;,
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