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 5,8-Dihydroxy-1,4-naphthoquinone
475-38-7

5,8-Dihydroxy-1,4-naphthoquinone synthesis

13synthesis methods
1,8-Dinitronaphthalene and 1,5-Dinitronaphthalene mixture or both alone and one of sulfur 40% fuming sulfuric ACID reaction, the product (5, 8 – dihydroxy – naphthoquinone) into Sulfurous acid?hydrogen salt.
-

Yield: 16.95%

Reaction Conditions:

with aluminum (III) chloride;sodium chloride at 200; for 2 h;High pressure;Friedel-Crafts Acylation;Temperature;

Steps:

1 Example 1 The method for the synthesis of naphthoquinone by molten salt method is as follows:
In the first step, the oven will be preheated to 160°C.Weigh the sample with 25% fullness of the hydrothermal reactor, including NaCl 2.10g, with a balance.Anhydrous AlCl 310.67g, maleic anhydride 1.18g and hydroquinone 1.10g;The weighed sample is placed in a grinding crucible, fully mixed, ground, and transferred to a hydrothermal reactor.The reaction vessel was screwed; the reaction vessel was placed in an oven that had been preheated to 200 DEG C. and subjected to Friedel-Crafts acylation reaction for 2 hours.After the reaction is complete, remove the reactor and allow the reactor vessel to cool to room temperature.A purple-black solid was obtained as a complex of 5,8-dihydroxy-1,4-naphthoquinone and tri-alumina;In the second step, transfer the purple-red solid obtained in the first step to a beaker.Add 20% hydrochloric acid solution to fully boil until bubbles are no longer generated, then filter to remove the upper solid;The solid was then dispersed with a small amount of ultrapure water and extracted three times with CH2Cl2.The resulting extract was dried under reduced pressure and dried in a vacuum oven under vacuum at 55°C for about 8 hours.0.3223 g of purple-red powder was obtained, namely naphthoquinone (5,8-dihydroxy-1,4-naphthoquinone).The theoretical yield of hydroquinone was 1.8998 g as the starting material, so the total yield was 16.95%.

References:

Yunnan China National Tobacco Industry Co., Ltd.;Hubei University;Chang Gang;Zhou Yang;Zhu Ruizhi;Liu Zhihua;Cao Yunbin;Cao Ribing CN107417508, 2017, A Location in patent:Paragraph 0028-0031; 0033-0042

5,8-Dihydroxy-1,4-naphthoquinone Related Search: