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:

青田县| 舟曲县| 叙永县| 平山县| 那曲县| 汽车| 景德镇市| 辽阳县| 弋阳县| 安西县| 桃园县| 永安市| 全南县| 揭东县| 自治县| 英超| 台南县| 阿尔山市| 长海县| 定兴县| 邢台市| 福泉市| 米泉市| 贺州市| 胶州市| 山西省| 襄樊市| 海安县| 凤庆县| 耒阳市| 阜宁县| 康定县| 沅江市| 略阳县| 四会市| 文化| 长春市| 怀集县| 合阳县| 仁化县| 车险|