Share a compound : 4-Chloro-2,5-difluoropyridine

At the same time, in my other blogs, there are other synthetic methods of this type of compound,851386-40-8, 4-Chloro-2,5-difluoropyridine, and friends who are interested can also refer to it.

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.851386-40-8, name is 4-Chloro-2,5-difluoropyridine, molecular formula is C5H2ClF2N, molecular weight is 149.53, as common compound, the synthetic route is as follows.Safety of 4-Chloro-2,5-difluoropyridine

To a solution of 4-chloro-2,5-difluoropyridine (200 nig, 1.33 mmol) and 4M HCl in dioxane (0.33 ml, 1.33 mmol) in 2-propanol (3 ml) was added hydrazine hydrate (134 mg, 2.68 mmol). Reaction mixture was stirred at rt for 1 month. Solvents were evaporated under vacuum. Aqueous NaHC03 solution was added to the mixture. Precipitate formed was filtered oft” washed with water and dried under vacuum yielding 51 mg of 4-chloro-5- fluoro-2-hydrazinylpyridine and 2,5-difluoro-4-hydrazinylpyridine as a 1/1 mixture.MS: m/z 162 I M I f ] . 1H NMR (DMSO-d6) delta: 8. 19 (br s, IH), 8.09 (d, 1 1 1 ).. 7.70 (d, 1 1 1 }.. 7.66 (d, H), 6.88 (d, IH), 6.55 (d, IH), 4.39 (d, 2H), 4.21 (br s, 2H ) To a solution containing the mixture of 4-chloro-5-fluoro-2-hydrazinylpyridine and 2,5-difluoro-4-hydrazinylpyridine (50 mg, 0.31 mmol) in THF (3 ml) at 0C was added triphosgene (92 mg, 0.31 mmol). Reaction mixture was stirred at 0C for 1 hour. Solvents were evaporated under vacuum. A solution of IM aqueous HCl was then added and the mixture was extracted 3 times with EtOAc. Organic layers were concentrated under vacuum. Evaporation residue was dissolved in IM NaOH solution and extracted twice with EtOAc. Aqueous phase was acidified with cone, HCl and extracted twice with EtOAc. Organic layers were dried and concentrated under vacuum. Evaporation residue was stirred in Et20, filtered off and dried under vacuum yielding 1 1 mg of pure 7-chloro-6-fluoro- [l,2,4]triazolo[4,3-a]pyridii -3(2H)-one. MS: m/z 188 [M+Hf. 1H NMR ( DM SO-d,.) delta: 12.71 (br s, IH), 8.27 (dd, IH), 7.75 (dd, IH)

At the same time, in my other blogs, there are other synthetic methods of this type of compound,851386-40-8, 4-Chloro-2,5-difluoropyridine, and friends who are interested can also refer to it.

Reference:
Patent; RICHTER GEDEON NYRT.; ORION CORPORATION; HAIKARAINEN, Anssi; JOUBERT, Muriel; KAROLYI, Benedek; KAeSNAeNEN, Heikki; PASSINIEMI, Mikko; POHJAKALLIO, Antti; SZANTO, Gabor; VAISMAA, Matti; (97 pag.)WO2019/43635; (2019); A1;,
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