Reference of 2729-34-2, As we all know, there are many different methods for the synthesis of a compound, and people can choose the synthesis method that suits their own laboratory according to the actual situation. 2729-34-2 name is 3,5-Dichloro-4-fluoroaniline, This compound is widely used in many fields, so it is necessary to find a new synthetic route. The downstream synthesis method of this compound is introduced below.
To a suspension of ethyl 2-cyanoacetimidate hydrochloride (0.50 g, 3.36 mmol, Eq: 1.00) in ethanol (5.2 mL), was added 3,5-dichloro-4-fluoroaniline (606 mg, 3.36 mmol, Eq: 1.00). The suspension was stirred overnight at room temperature, under a nitrogen atmosphere. The reaction mixture was filtered to remove the salts. The clear yellow filtrate was then treated with hydrazine (in water) (313 mg, 310 mu, 3.42 mmol, Eq: 1.02) and heated in an oil bath at 80- 85C for 4.5 h. The reaction was cooled to room temperature and concentrated. The residue was partitioned between EtOAc and water. The organic phase was removed, washed with brine, dried (Na2S04) and concentrated over celite. The crude material was purified by flash chromatography (silica gel, SF 15-24 g, 20% to 100% EtOAc in hexanes) to give a light brown oil, which was further purified by HPLC (reverse phase, Sunfire Prep C18 OBD [5 uM; 30×100 mm], 5% to 95% acetonitrile in water (each containing 0.1% TFA)). The product-containing fractions were combined and freeze-dried. The freeze-dried material was taken up in EtOAc and washed with aqueous NaHC03 (lx) and water (2x). The organic phases was dried (Na2S04) and concentrated. The residue was dissolved in acetonitrile-water and freeze-dried to give 45 mg (5%) of desired product as an off-white solid. MS m/z 261, 263 [M+H]
At the same time, in my other blogs, there are other synthetic methods of this type of compound, 3,5-Dichloro-4-fluoroaniline, and friends who are interested can also refer to it.
Reference:
Patent; F. HOFFMANN-LA ROCHE AG; HOFFMANN-LA ROCHE INC.; PLANCHER, Jean-Marc; WEIKERT, Robert James; WO2014/135423; (2014); A1;,
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