ChemicalBook CAS DataBase List Avobenzone

Avobenzone synthesis

12synthesis methods

Product Name:Avobenzone
CAS Number:70356-09-1
Molecular formula:C20H22O3
Molecular Weight:310.39

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

ROUTE 2

ROUTE 3

ROUTE 4

ROUTE 5

ROUTE 6

ROUTE 7

ROUTE 8

ROUTE 9

ROUTE 10

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

26537-19-9
258 suppliers
$16.00/25g

100-06-1 Synthesis

100-06-1
569 suppliers
$18.19/25g

70356-09-1
487 suppliers
$14.00/5g

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

258497-50-6 Synthesis

2-Propen-1-one, 3-[4-(1,1-dimethylethyl)phenyl]-1-(4-methoxyphenyl)-

258497-50-6
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inquiry

70356-09-1
487 suppliers
$14.00/5g

References

Benzoic acid, 4-(1,1-dimethylethyl)-, 1,1-dimethylethyl ester

92279-83-9
0 suppliers
inquiry

100-06-1 Synthesis

100-06-1
569 suppliers
$18.19/25g

70356-09-1
487 suppliers
$14.00/5g

References

943-27-1 Synthesis

943-27-1
199 suppliers
$6.00/1g

121-98-2 Synthesis

121-98-2
284 suppliers
$12.00/1mg

70356-09-1
487 suppliers
$14.00/5g

References

874-90-8 Synthesis

874-90-8
329 suppliers
$8.00/10g

2-BROMO-1-(4-TERT-BUTYL-PHENYL)-ETHANONE

30095-47-7
38 suppliers
$142.00/100mg

70356-09-1
487 suppliers
$14.00/5g

References

Avobenzone Related Search:

Monobenzone tert-Butyl hydroperoxide tert-Butyldimethylsilyl chloride Phenylhydrazine PHENYL VALERATE Dibenzoylmethane tert-Butyl methyl ether Butyl acetate BOURGEONAL CHEMBRDG-BB 5213821