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-2,3-difluorophenol
144292-32-0

4-Bromo-2,3-difluorophenol synthesis

2synthesis methods
1-BROMO-4-METHOXY-2,3-DIFLUOROBENZENE

406482-22-2

4-Bromo-2,3-difluorophenol

144292-32-0

The general procedure for the synthesis of 2,3-difluoro-4-bromophenol from 4-bromo-2,3-difluoroanisole was as follows: to a stirred solution of 1-bromo-2,3-difluoro-4-methoxybenzene (3 g, 13.45 mmol) in dichloromethane (DCM, 30 mL) was slowly added dropwise to a dichloromethane (DCM) solution of 1 M boron tribromide (BBr3) (26.9) at -20 °C. The dropwise addition time was controlled to 10 min. mL, 26.9 mmol), and the dropwise addition time was controlled over 10 min. The cooling bath was removed and the reaction mixture was continued to be stirred at room temperature for 12 hours. Subsequently, the reaction mixture was cooled to 10 °C and the reaction was quenched with saturated aqueous sodium bicarbonate solution (100 mL). The mixture was diluted with dichloromethane (DCM, 150 mL) and the organic layer was separated, dried over anhydrous sodium sulfate and concentrated under reduced pressure to afford the target product 4-bromo-2,3-difluorophenol (2 g, 9.47 mmol, 70% yield) in the form of a dark red oil. NMR hydrogen spectrum (400MHz, chloroform-d): δ 7.15-7.21 (m, 1H), 6.69-6.76 (m, 1H), 5.30-5.31 (m, 1H) ppm.

6418-38-8 Synthesis
2,3-Difluorophenol

6418-38-8
342 suppliers
$10.00/1g

-

Yield: 73%

Reaction Conditions:

with acetic acid;potassium bromide in water;acetic acid at 35;regioselective reaction;

Steps:

4.2. General Procedure for the Bromination
General procedure: 0.11 g (1.0 mmol) of 4-methylphenol, 5 mL of acetic acid, 0.5 mL of water, and 0.12 g (1.0 mmol)potassium bromide were placed in round-bottomed flask. Then, 0.19 g (0.2 mmol)ZnAl-BrO3--LDHs was added in the flask under stirring at 35 °C. After the addition, stirring wascontinued to the end of reaction (monitored by thin layer chromatography). The residualZnAl-BrO3--LDHs were removed by centrifugation. The product was extracted with 3 × 10 mLdichloromethane. The combined extract was washed with sodium sulfite solution, brine, and dried(Na2SO4). Evaporation of the solvent left the crude product. The crude product was purified bycolumn chromatography over silica gel (ethyl acetate-petroleum ether) to obtain pure product.

References:

Wang, Ligeng;Feng, Chun;Zhang, Yan;Hu, Jun [Molecules,2020,vol. 25,# 4,art. no. 914] Location in patent:supporting information

4-Bromo-2,3-difluorophenol Related Search:

桑植县| 甘南县| 锦州市| 会同县| 会同县| 微博| 江陵县| 黄大仙区| 栾城县| 儋州市| 尼玛县| 阜新市| 弋阳县| 南宁市| 台东县| 大同县| 凉城县| 威宁| 西丰县| 桦川县| 昌邑市| 噶尔县| 景谷| 巴林右旗| 澄迈县| 涟水县| 上栗县| 梨树县| 东光县| 新野县| 静安区| 玉树县| 乐昌市| 建湖县| 拉萨市| 舒城县| 通州区| 海盐县| 新化县| 九寨沟县| 天镇县|