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 Catechol
120-80-9

Catechol synthesis

14synthesis methods
Pyrocatechol may be obtained by the fusion of o-phenolsulfonic acid with alkali, by heating chorophenol with a solution of sodium hydroxide at 200°C in an autoclave, or by cleavage of the methyl ether group of guaiacol (obtained from beechwood tar) with hydriodic acid.
-

Yield:120-80-9 99%

Reaction Conditions:

Stage #1: 2-methoxy-phenolwith pyridine;iodine;aluminium in acetonitrile; for 18 h;Reflux;
Stage #2: with hydrogenchloride in lithium hydroxide monohydrate;acetonitrile at 20;

Steps:

14 Example 14 (guaiacol demethylation)

To a 100 ml eggplant flask were added iodine (2.098 g), aluminum powder (0.467 g) and acetonitrile (50 ml), heated toReflux, stir for 2 hours to the purple red of iodine disappears. Then pyridine (1.889 g) and guaiacol (0.621 g) were added to continue the reaction18 hours. After stirring at room temperature, 2 mol / L dilute hydrochloric acid (10 ml) was added to the reaction solution, and the mixture was extracted with ethyl acetate(50 ml x 3). The organic phases were combined and dried over anhydrous sodium sulfate. The filtrate was evaporated to dryness with a rotary evaporator and the residue passed throughPurified column chromatography (mobile phase ethyl acetate: petroleum ether = 1: 1, volume ratio) to obtain catechol (colorless needleCrystal, 0.546 g, yield 99%).

References:

CN106278825,2017,A Location in patent:Paragraph 0077; 0078; 0079

Catechol Related Search:

阿勒泰市| 新营市| 上犹县| 潼关县| 上杭县| 元谋县| 木兰县| 岑巩县| 元朗区| 新昌县| 阿拉善左旗| 台东市| 通海县| 德江县| 察隅县| 桑植县| 正阳县| 甘南县| 台北市| 南澳县| 霍林郭勒市| 平江县| 依兰县| 轮台县| 廉江市| 抚远县| 天水市| 奇台县| 怀集县| 印江| 罗定市| 涟水县| 昭觉县| 扬中市| 三亚市| 南宫市| 宁津县| 禄丰县| 安国市| 樟树市| 巧家县|