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 56741-34-5 as follows. name: Methyl 5-amino-2-fluorobenzoate
EXAMPLE 8 Methyl 2-bromo-3-(3-methoxycarbonyl-4-fluorophenyl)propionate To a solution of methyl 5-amino-2-fluorobenzoate (4.12 g) in 47% hydrobromic acid (11.4 ml), methanol (20 ml) and acetone (50 ml), a solution of sodium nitrite (1.88 g) in water (3 ml) was slowly added dropwise under cooling with salt-ice and stirring so as to keep an internal temperature of not higher than -5 C. After stirred for 30 minutes as it was, ice bath was removed, methyl acrylate (13.3 ml) was added, and cuprous oxide (225 mg) was added little by little while stirring vigorously. After no nitrogen became to generate, the reaction liquor was concentrated under reduced pressure. The residue was dissolved into ethyl acetate, washed with water, saturated aqueous solution of sodium hydrogencarbonate and water in order, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The residue was purified by means of silica gel column chromatography (developing solvent; n-hexane:ethyl acetate=10:1) to obtain 3.48 g (45%) of aimed compound as an oily material. 1 H NMR (CDCl3), delta: 3.25 (1H, dd, J=7.3, 14.6 Hz), 3.46 (1H, dd, J=7.8, 14.2 Hz), 3.75 (3H, s), 3.93 (3H, s), 4.38 (1H, t, J=7.8 Hz), 7.09 (1H, dd, J=8.8, 10.8 Hz), 7.38 (1H, ddd, J=2.4, 4.4, 8.8 Hz), 7.80 (1H, dd, J=2.4, 6.3 Hz) MS(m/z): 318, 320 (M+)
According to the analysis of related databases, 56741-34-5, the application of this compound in the production field has become more and more popular.
Reference:
Patent; Kyorin Pharameuticals Co., Ltd.; US6001862; (1999); A;,
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