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 4,4'-(Hexafluoroisopropylidene)diphthalic anhydride
1107-00-2

4,4'-(Hexafluoroisopropylidene)diphthalic anhydride synthesis

10synthesis methods
Acetic anhydride

108-24-7

2,2-Bis(3,4-dimethylphenyl)hexafluoropropane

65294-20-4

4,4'-(Hexafluoroisopropylidene)diphthalic anhydride

1107-00-2

The general procedure for the synthesis of hexafluorodianhydride (6FDA) from ethanoic anhydride and 2,2-bis(3,4-dimethylphenyl)hexafluoropropane was as follows: in a 2000 mL three-necked flask, 14.40 g of 4,4'-(hexafluoroisopropylidene)bis(o-xylene) and solvent mixture of pyridine (200 mL) and water (100 mL) were added. The mixture was heated to 100 °C and then 38.0 g of potassium permanganate was added slowly and the reaction was maintained for 3 hours. Upon completion of the reaction, a small amount of ethanol was added dropwise to quench the unreacted potassium permanganate. The reaction mixture was filtered and the pyridine was subsequently recovered from the filtrate by distillation. The pH of the remaining solution was adjusted to 1 and water was removed to dryness by evaporation. 320 mL of acetone was added to dissolve the organic material, and after filtration to remove insoluble material, the filtrate was evaporated to dryness to give hexafluorobutyric acid in 80% yield. A mixture of 4.80 g of hexafluorobutyric acid with 8 mL of acetic anhydride and 8 mL of xylene was added to a 150 mL flask and reacted at 140 °C for 40 min. After completion of the reaction, the crude product was cooled and filtered to obtain hexafluorodianhydride (6FDA) crude product. After purification by sublimation and drying, hexafluorodianhydride (6FDA) with purity greater than 99.5% was obtained in 79% yield.

-

Yield:1107-00-2 96%

Reaction Conditions:

with acetic anhydride at 120; for 4 h;Temperature;

Steps:

1.2; 15-16; 1-2

Add hexafluorotetraacid to 40ml of anhydrous acetic anhydride, stir and reflux at 120°C for 4h, the molar ratio of hexafluorotetraacid to anhydrous acetic anhydride is 1:3.5. The reaction solution was cooled by an ice-water bath to precipitate white crystals, and after drying, the crude hexafluorodianhydride was obtained with a purity of 98%.The crude hexafluorodianhydride was added to 20ml of anhydrous trifluoroacetic anhydride and mixed, and then heated to reflux at 35°C for 1.5h. The molar ratio of crude hexafluorodianhydride to anhydrous trifluoroacetic anhydride was 1:1.5. The reaction solution was cooled by an ice-water bath to precipitate white crystals, and after drying, the finished product of hexafluorodianhydride was obtained with a purity of 99.8%. The yield of S2 step was 96%.

References:

CN113480504,2021,A Location in patent:Paragraph 0026; 0030-0031; 0045-0046; 0047-0048; 0049; 0051

4,4'-(Hexafluoroisopropylidene)diphthalic anhydride Related Search:

明光市| 密山市| 和田市| 收藏| 石狮市| 宜春市| 营口市| 鹿泉市| 和田市| 新丰县| 四会市| 淮阳县| 汉阴县| 荃湾区| 都昌县| 大荔县| 满洲里市| 成都市| 崇信县| 利川市| 平舆县| 新田县| 衡阳市| 龙里县| 南投县| 教育| 宁武县| 甘孜| 宁南县| 金乡县| 佳木斯市| 宽甸| 澄江县| 惠安县| 临汾市| 淮阳县| 布尔津县| 岗巴县| 呼伦贝尔市| 航空| 阿巴嘎旗|