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 4-Bromo-2,6-difluorobenzaldehyde
537013-51-7

4-Bromo-2,6-difluorobenzaldehyde synthesis

5synthesis methods
4-Bromo-2,6-difluorobenzaldehyde can be used as organic synthesis intermediate and pharmaceutical intermediate, mainly in laboratory research and development process and chemical production process. To a solution of 1-bromo-3,5 difluoro benzene in THF was added LDA  at 0-5°C and stirred for 30 min. Then added solution of DMF with THF and again stirred for 3 h at 0-5°C. Quenched the reaction mass in acetic acid at 0°C and extracted with ethyl acetate. The organic layer was concentrated to give 4-Bromo-2,6-difluorobenzaldehyde. 
-

Yield:537013-51-7 78%

Reaction Conditions:

Stage #1:3,5-difluorobromobenzene with lithium diisopropyl amide in tetrahydrofuran at -70; for 0.5 h;
Stage #2:N-Formylpiperidine at -70 - 0;

Steps:

1.1 4-bromo-2,6-difluorobenzaldehyde (1)
55 ml (0.11 mmol) of 2 M lithium diisopropylamide are added with stirring at -70° C. to a solution of 19.3 g (0.1 mmol) of 1-bromo-3,5-difluorobenzene in 120 ml of dried tetrahydrofuran.After 30 minutes, N-formylpiperidine is added dropwise at this temperature.The mixture is allowed to warm to 0° C. At about 0° C., the reaction mixture is poured into cold water, acidified using 10% HCl and extracted twice with methyl tert-butyl ether.The combined organic phases are washed with water, dried over Na2SO4 and filtered, and the solvent is removed under reduced pressure.The residue is filtered through SiO2 (heptane/dichloromethane 1:1), (yield: 17.6 g, 78%).

References:

Merck Patent GmbH US2004/6235, 2004, A1 Location in patent:Page 11

FullText

4-Bromo-2,6-difluorobenzaldehyde Related Search:

连山| 康平县| 上杭县| 石棉县| 垣曲县| 绍兴县| 怀化市| 宁强县| 威宁| 镇沅| 木兰县| 镇平县| 汤原县| 奈曼旗| 文安县| 和静县| 澄江县| 文昌市| 公主岭市| 兴安县| 广饶县| 含山县| 赤城县| 旬邑县| 大石桥市| 抚宁县| 鄢陵县| 鸡泽县| 永吉县| 饶平县| 石屏县| 张家港市| 山丹县| 东丰县| 尖扎县| 古交市| 绥化市| 左贡县| 上蔡县| 崇州市| 东兰县|