天堂网亚洲,天天操天天搞,91视频高清,菠萝蜜视频在线观看入口,美女视频性感美女视频,95丝袜美女视频国产,超高清美女视频图片

Welcome to chemicalbook!
Chinese English Japanese Germany Korea
400-158-6606
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-Fluoro-2-methylphenylboronic acid
139911-29-8

4-Fluoro-2-methylphenylboronic acid synthesis

4synthesis methods
-

Yield: 61.5%

Reaction Conditions:

Stage #1:2-Bromo-5-fluorotoluene with n-butyllithium in tetrahydrofuran;hexane at -78; for 1 h;
Stage #2:Triisopropyl borate in tetrahydrofuran;hexane for 1 h;

Steps:

1 Example 1: synthesis of 2-methyl-4-fluorophenylboronic acid
In a solution of 2-bromo-5-fluorotoluene (250 g) in tetrahydrofuran (250 ml) and n- hexane (250 ml) was added n-butyl lithium (991.5 ml) drop wise at -78°C in a dry-ice bath. The solution was stirred for an hour. Triisopropyl borate (373.11 g) was added drop wise and reaction was stirred for further an hour. The resulting solution was diluted with aqueous sodium hydroxide and then washed with n-heptane. The pH of the aqueous layer was adjusted to pH 2-3 using hydrochloric acid and then extracted with ethyl acetate. The organic layer was concentrated under vacuum. This was dissolved in ethyl acetate at about 40°C and to this heptane was added to obtain 2- methyl-4-fluorophenylboronic acid. Yield: 61.5%; HPLC purity: 99.00%.

References:

GLENMARK PHARMACEUTICALS LIMITED;KUDUVA, Srinivasan Subramanian;-, Rajender;CHORAGHE, Mahendra Joma;NAIK, Samir;BHIRUD, Shekhar Bhaskar WO2017/125835, 2017, A1 Location in patent:Paragraph 00117

4-Fluoro-2-methylphenylboronic acid Related Search: