一二三四区视频,亚洲少妇熟女色,日本久热无码视频网,欧美国产日韩大尺度,亚洲a视频,久久少妇一区二区,日韩999无码视频,刺激久久久久久久,啊啊啊啊不要啊在线

Welcome to chemicalbook!
Chinese English Japanese Germany Korea
010-86108875
Try our best to find the right business for you.
Do not miss inquiry messages Please log in to view all inquiry messages.

Welcome back!

ChemicalBook CAS DataBase List 5-Fluoro-2-hydroxypyridine
51173-05-8

5-Fluoro-2-hydroxypyridine synthesis

2synthesis methods
5-Fluoro-2-hydroxypyridine is synthesised using 5-fluoro-2-methoxypyridine as a raw material by chemical reaction. The specific synthesis steps are as follows:
A total of 4.6 L of toluene solution containing 3-80 was placed in several sealed tubes and treated with 900 ml of 35percent HCl at 145° C. for 2 hr. LC/MS showed no starting material, only 4. The toluene solution was decanted and discarded. The aqueous phase was washed with EtOAc and concentrated down to remove volatiles to afford a brown solid containing the desired fluoro-hydroxypyridine 4-80. [1488] A total of 244 g of this solid was collected and taken to next step as is (it was not completely dry). [1489] Note: We have subsequently run this by decanting the toluene layer first prior to heating to reduce volumes. Same reaction was carried out using HBr (48percent in H2O) at 100° C. for 6 h with similar result to the literature procedure 49percent yield. [1490] Ref: J. Heterocyclic Chem., 10, 779, 1973 (for above Reactions, Including Analytical Data).
5-Fluoro-2-hydroxypyridine synthesis
-

Yield:51173-05-8 49%

Reaction Conditions:

with hydrogen bromide in water at 100; for 6 h;

Steps:


A total of 4.6 L of toluene solution containing 3-80 was placed in several sealed tubes and treated with 900 ml of 35% HCl at 145° C. for 2 hr. LC/MS showed no starting material, only 4. The toluene solution was decanted and discarded. The aqueous phase was washed with EtOAc and concentrated down to remove volatiles to afford a brown solid containing the desired fluoro-hydroxypyridine 4-80. [1488] A total of 244 g of this solid was collected and taken to next step as is (it was not completely dry). [1489] Note: We have subsequently run this by decanting the toluene layer first prior to heating to reduce volumes. Same reaction was carried out using HBr (48% in H2O) at 100° C. for 6 h with similar result to the literature procedure 49% yield. [1490] Ref: J. Heterocyclic Chem., 10, 779, 1973 (for above Reactions, Including Analytical Data)

References:

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 Location in patent:Page 211

FullText

5-Fluoro-2-hydroxypyridine Related Search:

阿合奇县| 大厂| 汉沽区| 新沂市| 万安县| 彩票| 蒙山县| 依兰县| 铅山县| 绿春县| 社会| 太仓市| 苏州市| 瑞金市| 四川省| 壶关县| 高邑县| 娱乐| 庆元县| 永州市| 沙坪坝区| 中江县| 泽普县| 托里县| 芦溪县| 商水县| 望谟县| 黎川县| 江都市| 黔江区| 长丰县| 民丰县| 万荣县| 攀枝花市| 靖远县| 杨浦区| 伽师县| 封丘县| 丰城市| 天水市| 余姚市|