With the rapid development and complex challenges of chemical substances, the synthesis of new drugs is usually one of the most effective ways to increase yield.103999-77-5, name is 2,5-Dichloro-3-fluoropyridine, molecular formula is C5H2Cl2FN, molecular weight is 165.98, as common compound, the synthetic route is as follows.Quality Control of 2,5-Dichloro-3-fluoropyridine
(c) 64.6 g (1.11 mol) of potassium fluoride and 11.25 g (0.074 mol) of caesium fluoride are suspended in 240 ml of sulfolane and the suspension is heated to 140° C. 50 mol of sulfolane are distilled off by decreasing the pressure and then 61.4 g (0.37 mol) of 2,5-dichloro-3-fluoropyridine and 1.45 g (0.0055 mol) of 18-crown-6 in 20 ml of sulfolane are added to the suspension. This reaction mixture is stirred for 35 hours at 140° C. and then taken up in ice water. The product is isolated from the aqueous mixture either by extraction with ether or by steam distillation, affording 48.7 g (88percent of theory) of 5-chloro-2,3-difluoropyridine, b.p. 65°-66° C. at 133 mbar.
At the same time, in my other blogs, there are other synthetic methods of this type of compound,103999-77-5, 2,5-Dichloro-3-fluoropyridine, and friends who are interested can also refer to it.
Reference:
Patent; Ciba-Geigy Corporation; US4831148; (1989); A;,
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