At the same time, in my other blogs, there are other synthetic methods of this type of compound,51173-05-8, 5-Fluoro-2-hydroxypyridine, and friends who are interested can also refer to it.
Related Products of 51173-05-8, Researchers who often do experiments know that organic synthesis is a process of preparing more complex target molecules from simple raw materials through one or more chemical reactions. Generally, it requires fewer steps,and cheap raw materials. 51173-05-8, name is 5-Fluoro-2-hydroxypyridine. A new synthetic method of this compound is introduced below.
The solid from above containing (4-80) was divided in 4 batches and treated with H2SO4 and fuming HNO3 as shown below. The amounts used were: Compound 4-80 was dissolved in sulfuric acid (the larger amounts indicated above) at rt and then heated to 65 C. A preformed solution of fuming nitric acid and sulfuric acid (the smaller amount indicated above) was added dropwise. The temperature was kept between 65 C. and 80 C. (rxn is exothermic and although the bath is at 65 C., temperature goes higher, usually 75, sometimes 80 C.). After the addition was complete, the reaction mixture was heated at 65 C. for an additional hr. The reaction mixture was then cooled to rt and poured in a flask containing ice) (20 g of ice/gr compound, evolution of gas occurred). A solid precipitated out and it was collected by filtration (1HNM? showed 4-80 and something else (discarded)). [1493] The aqueous layer was extracted with AcOEt several times (3-5) and concentrated on a rotary evaporator under vacuum to afford a solid that was triturated with ether to afford 5-80 as a bright yellow solid. A total of 117 g of desired product was collected in the first crop (27% yield from diazonium salt). A portion did not crystallize: this oil was triturated with MeOH and Et2O to afford 3.6 g of 5-80; another precipitation from the mother liquid afforded an additional 6.23 g of the desired product 5-80 [1494] Total:117.0+3.6+6.23 =126.83. 30.4%). Yield for 3 steps (decomposition of diazonium salt; deprotection and nitration). [1495] Analytical data from Notebook: 53877-115: 1HNMR(delta, MeOD): 8.56-8.27 (dd, J=7.5, 3.3 Hz, 1H), 8.01 (d, J=3.3 Hz, 1H); LC/MS(M+1)+=158.9; rt=0.15 min. [1496] Note: A portion of the aqueous acidic solution was taken and neutralized with Na2CO3 until effervescence stopped and then it was extracted with AcOEtA different product was obtained. No desired product in these extracts.
At the same time, in my other blogs, there are other synthetic methods of this type of compound,51173-05-8, 5-Fluoro-2-hydroxypyridine, and friends who are interested can also refer to it.
Reference:
Patent; Wang, Tao; Zhang, Zhongxing; Meanwell, Nicholas A.; Kadow, John F.; Yin, Zhiwei; Xue, Qiufen May; Regueiro-Ren, Alicia; Matiskella, John D.; Ueda, Yasutsugu; US2004/110785; (2004); A1;,
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem