成人免费xx,国产又黄又湿又刺激不卡网站,成人性视频app菠萝网站,色天天天天

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 Avobenzone
70356-09-1

Avobenzone synthesis

12synthesis methods
Avobenzone is a dibenzoylmethane compound commonly found in sunscreens and can photoisomerize after exposure to near-ultraviolet light. At equilibrium, Avobenzone exists as a chelated enol characterized by a strong intramolecular hydrogen bond. The photochemistry of Avobenzone includes keto-enol tautomerization, cis-trans isomerization, rotation about the single bond and α bond cleavages of carbonyl groups. Findings suggest that torsion around the double C2-C3 bond of photoexcited chelated enol leads to internal conversion to the ground state and formation of rotamer E. In addition, opening of the chelated hydrogen ring by torsion of the hydroxyl group creates non-chelated enol. The possible mechanisms of rotamer Z formation are discussed.
Synthetic Routes
  • ROUTE 1

    • 202112075825533382.jpg

    Sun, Dong-Wei; Jiang, Min; Liu, Jin-Tao. Novel Bifunctionalization of Activated Methylene: Base-Promoted Trifluoromethylthiolation of β-Diketones with Trifluoromethanesulfinyl Chloride. Chemistry - A European Journal. Key Laboratory of Organofluorine Chemistry, Shanghai Institute of, Organic Chemistry. University of Chinese Academy of Science, Chinese Academy of Science. Shanghai, Peop. Rep. China 200032. Volume 25. Issue 46. Pages 10797-10802. 2019

  • ROUTE 2

    • 202112071347482091.jpg

    Cheng, Jianhua; Wang, Xiaojun; Wu, Chongcai; Wan, Jianxin. Preparation technology of sunscreen agent Parsol 1789.Xiangliao Xiangjing Huazhuangpin. Chemical Engineer School. The South China University of Technology. Zhanjiang, Peop. Rep. China 510641. Issue 3. Pages 8-10. 2002.

  • ROUTE 3

    • 202112070657862553.jpg

    Li, Min; Wei, Dan; Liu, Zhi-xiong. Synthesis of tert - butyl - methoxy - dibenzoylmethane under microwave irradiation. Riyong Huaxue Gongye. Department of Pharmacy. Guangdong Pharmaceutical University. Guangdong, Peop. Rep. China 510006. Volume 39. Issue 3. Pages 179-182. 2009

  • ROUTE 4

    • 202112070221642030.jpg

    Miralles, Ricardo; Nonell, Santiago; Raga, Manuel M.; Giuglietta, Antonio.Industrial preparation of benzoic acid ester derivatives for use as sunscreen lotions and cosmetics. Assignee Ferrer Internacional, S. A., Spain; Teixido, Jordi. WO 2006100225. 2006

  • ROUTE 5

    • 202112071494913478.jpg

    Habeck, Thorsten; Prechtl, Frank. Preparation of dibenzoylmethanes. Assignee Basf Aktiengesellschaft, Germany. EP 994092. 2000

  • ROUTE 6

    • 202112078025588865.jpg

    Koide, Masashi; Ishii, Hiroshi. Pressure-sensitive adhesive compositions containing polyesters and diphenyldiketones with excellent UV-shielding properties and optical laminates and organic electroluminescent cells using them. Assignee Toyo Ink Mfg. Co., Ltd., Japan. JP 2008297478. 2008

  • ROUTE 7

    • 202112077605971485.jpg

    Frater, Georg; Huber, Ulrich. Process for the purification of 1,3-diketones. Assignee Roche Vitamins A.-G., Switz. WO 2002062738. 2002

  • ROUTE 8

    • 202112073419372316.jpg

    Liu, Zhongchun. A method for synthesis of avobenzone. Assignee Jiangxi Hengtong Technology Development Co., Ltd., Peop. Rep. China. CN 104876814. 2015

  • ROUTE 9

    • 202112072147590196.jpg

    Liu, Qifa; Wang, Rong; Yang, Jian. Preparation of ultraviolet absorbent avobenzone. Assignee Suqian Cosmos Chemical Co., Ltd., Peop. Rep. China. CN 108658741. 2018

  • ROUTE 10

    • 202112078763989986.jpg

    Wang, Min. Method for synthesizing avobenzone. CN 109867597. 2019

202112075825533382.jpg

Sun, Dong-Wei; Jiang, Min; Liu, Jin-Tao. Novel Bifunctionalization of Activated Methylene: Base-Promoted Trifluoromethylthiolation of β-Diketones with Trifluoromethanesulfinyl Chloride. Chemistry - A European Journal. Key Laboratory of Organofluorine Chemistry, Shanghai Institute of, Organic Chemistry. University of Chinese Academy of Science, Chinese Academy of Science. Shanghai, Peop. Rep. China 200032. Volume 25. Issue 46. Pages 10797-10802. 2019

-

Yield:70356-09-1 95%

Reaction Conditions:

with potassium methanolate in toluene at 110; under 750.075 Torr; for 2 h;Product distribution / selectivity;

Steps:

1

condensation with various bases In a reaction flask with a 30 ml toluene and the base were provided under a blanket of inert gas. 20 mmole 4-tert-Butyl benzoic acid methyl ester (TBBM) and 20 mmole p-methoxy acetophenone (pMAc) was added. The mixture was stirred at about 110°C/ 1 bar while alcohol and toluene was slowly distilled off (toluene was occasionally replenished to maintain 20 ml volume). After complete conversion of TBBM and pMAc the reaction mixture was cooled and acidified with 2M acetic acid. An aliquot was analyzed by HPLC for the chemical yield of 4-te/f-Butyl-4'-methoxydibenzoylmethane. The results are given in table 1. Table 1 : ResultsAs can be seen from the results in table 1 the use of a potassium alcoholate results in higher yields and shorter reaction times compared to the use of other alkali or earth alkali alcoholates.Furthermore, the potassium salt did not crystallize and remained homogeneously dissolved in toluene whereas the sodium, magnesium and the lithium salt formed a crystalline inhomogeneous mixture

References:

WO2012/84770,2012,A1 Location in patent:Page/Page column 8-9

Avobenzone Related Search: