Electric Literature of 28342-75-8,Some common heterocyclic compound, 28342-75-8, name is 1,5-Dibromo-2,4-difluorobenzene, molecular formula is C6H2Br2F2, 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.
To a stirred solution of 1,5-dibromo-2,4-difluorobenzene (20.0 g, 73.6 mmol) in diethyl ether (400 mL) in a dry ice bath was added n-butyl lithium in hexanes (31 ml, 2.5 M, 77 mmol) so that the temperature of the reaction mixture stayed between -65¡ã C and -70¡ã C and then the mixture was stirred at -70¡ã C for further 0.5 h. N,N-dimethylformamide (7.1 ml, 92 mmol) was slowly added so that the temperature of the reaction mixture stayed between -65¡ã C and -70¡ã C and then the mixture was stirred at -70¡ã C for fu rther 0.5 h. The dry ice bath was removed and the mixture was allowed to warm up to 0¡ã C. A m ixture of water (180 mL) and acetic acid (1 1 ml, 200 mmol) was added and the mixture was stirred for 15 min. The phases were separated and the aqueous phase was extracted with ethyl acetate. The organic phases were combined and washed with saturated sodium chloride solution, dried (sodium sulfate), filtered and the solvent was removed in vacuum. Silicagel chromatography gave 12.6 g (77 percent yield) of the title compound. LC-MS (Method 1 ): Rt = 1 .09 min; MS (ESIpos): m/z = 220 [M+H]+ 1H-NMR (400 MHz, DMSO-d6) d [ppm]: 2.518 (0.45), 7.716 (4.55), 7.738 (4.98), 7.742 (4.92), 7.765 (4.71 ), 8.141 (4.86), 8.159 (6.75), 8.179 (4.87), 10.079 (16.00).
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 1,5-Dibromo-2,4-difluorobenzene, its application will become more common.
Reference:
Patent; BAYER PHARMA AKTIENGESELLSCHAFT; SCHULZE, Volker; HEINRICH, Tobias; CHRIST, Clara; BRIEM, Hans; FARIA ALVARES DE LEMOS, Adelaide, Clara; BADER, Benjamin; HOLTON, Simon; BOeMER, Ulf; LIENAU, Philip; KUHNKE, Lara, Patricia; (122 pag.)WO2019/185525; (2019); A1;,
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