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 Menadiol diacetate
573-20-6

Menadiol diacetate synthesis

9synthesis methods
Menadione

58-27-5

Acetic anhydride

108-24-7

Menadiol diacetate

573-20-6

General procedure for the synthesis of vitamin K4 from 2-methyl-1,4-naphthoquinone (20.0 g) and acetic anhydride (29.65 g): 2-methyl-1,4-naphthoquinone was first dissolved in ethyl acetate (200 g). Subsequently, acetic anhydride, 4-dimethylaminopyridine (DMAP, 1.42 g), and palladium/carbon catalyst (Pd/C, 0.6 g) were added to the solution. The reaction mixture was stirred at room temperature in a hydrogen atmosphere overnight. Upon completion of the reaction, the Pd/C catalyst was removed by filtration. The filtrate was washed with brine and the organic layer was separated. The organic layer was concentrated and recrystallized in a solvent mixture of water (60 g) and isopropanol (IPA, 80 g) to yield 28.0 g of vitamin K4 as white crystals (yield: 84.2%, HPLC purity: 99.8%). The structure of the compound was characterized by 1H-NMR with the following chemical shifts: δ 2.27 (s, 3H), 2.46 (s, 3H), 2.50 (s, 3H), 7.27 (s, 1H), 7.55-7.62 (m, 2H), 7.85-7.89 (d, 2H).

-

Yield:573-20-6 90.2 %

Reaction Conditions:

with pyridine at 65 - 70;

Steps:

1.2; 2; 3.2

(2) the above0.45 g (0.006 mol) of pyridine is added to the 2-methyl-1,4-naphthalenediol ethyl acetate solution,17.1 g (0.167 mol) of acetic anhydride was added dropwise at 65-70° C. and aged at the same temperature for 3 hours. The organic layer was washed with city water and 5% sodium bicarbonate water,The organic layer was concentrated, and a mixed solution of isopropanol (IPA) and city water was added to the residue. The resulting slurry was filtered and dried under reduced pressure to give 12.0 g of colorless crystalline powder of 1,4-diacetoxy-2-methylnaphthalene.(0.046 mol) was obtained.HPLC purity is 99.96 Area%,The yield from bisulfite trihydrate of 2-methylnaphthoquinone was 90.2%.

References:

JP2023/16443,2023,A Location in patent:Paragraph 0023-0025

Menadiol diacetate Related Search:

肇源县| 南投县| 体育| 宣威市| 横山县| 宁明县| 崇义县| 丰原市| 华亭县| 炎陵县| 宝坻区| 武义县| 社旗县| 商洛市| 尚义县| 敦化市| 琼结县| 绥江县| 威宁| 公主岭市| 什邡市| 潼关县| 祁连县| 镇远县| 措美县| 电白县| 南城县| 古交市| 神木县| 邵东县| 平阴县| 大港区| 陇川县| 土默特左旗| 鄂伦春自治旗| 云和县| 新巴尔虎右旗| 沈阳市| 东方市| 光山县| 腾冲县|