3- (3,5-Di- tert- butyl-4-hydroxyphenyl) propionic acid methyl ester
|Surname||3- (3,5-Di- tert- butyl-4-hydroxyphenyl) propionic acid methyl ester|
|Molecular formula||C 18 H 28 O 3|
white crystal powder
|External identifiers / databases|
|Molar mass||292.42 g mol −1|
1.09 g cm −3
66.1 ° C
0.00002 hPa at 25 ° C
|As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .|
3- (3,5-Di- tert- butyl-4-hydroxyphenyl) propionic acid methyl ester ( Metilox ) is a derivative of 4-hydroxycinnamic acid , which is hydrogenated to 3- (4-hydroxyphenyl) propanoic acid (4-hydroxydihydrocinnamic acid) and esterified to the methyl ester . As a sterically hindered phenol , Metilox has antioxidant properties and is the starting compound for longer-chain and more complex esters and amides. a. be used as stabilizers for polymers.
In the synthesis of methyl- di - tert- butylhydroxyhydrocinnamate ( 2 ), potassium tert -butanolate is used to generate the mesomeric anion from 2,6-di- tert- butylphenol ( 1 ) , which in its carbanion form in a Michael addition reacts with methyl acrylate . After acidification, the product can be isolated as a yellowish oil by vacuum distillation , which solidifies to a white solid.
3- (3,5-Di- tert- butyl-4-hydroxyphenyl) propionic acid methyl ester is a white solid which is initially obtained as a yellowish oil during synthesis. The compound is practically insoluble in water, but dissolves in many organic solvents. Its poor biodegradability is problematic if it should get into the environment as a component of liquid mixtures.
Like its starting compound 2,6-di- tert- butylphenol, methyl 3- (3,5-di- tert- butyl-4-hydroxyphenyl) propionate is also effective as a radical scavenger as an antioxidant in polymers, especially in polyolefins and polyurethanes . It is also used in technical oils, such as. B. engine oils , lubricating oils and gear oils , used in hydraulic fluids and cooling lubricants ( English metal working fluids , MWF). Metilox is an intermediate for a number of hindered phenols with longer alkyl chains or spatially more bulky structures in order to reduce volatility and diffusion in polymers and to suppress fogging , especially in vehicle interiors and living spaces.
The higher esters of Metilox (Octyl = Irganox 1135, Octadecyl = Irganox 1076, Pentaerythrityl = Irganox 1010) are mostly obtained by transesterification with the respective alcohol under catalysis with z. B. alkali hydroxides , such as lithium hydroxide or with organic tin compounds , such as dibutyltin oxide .
The Michael addition of higher acrylic acid esters, such as. B. Octadecyl acrylate on 2,6-di- tert- butylphenol analogous to the Metilox synthesis is also mentioned, but not technically relevant.
The most efficient possible stabilization of polymers against oxidative degradation initiated by light and heat usually requires the addition of anti- aging agents as mixtures (so-called " stabilizer packages ") of hindered phenols and other compounds, such as the antioxidant phosphonates , radical scavengers such as HALS ( hindered amine light stabilizers ) and UV absorbers such as benzophenones , benzotriazoles or hydroxyphenyl triazines .
- George Wypych (Ed.): Handbook of UV Degradation and Stabilization, 2nd Edition . ChemTec Publishing, Toronto 2015, ISBN 978-1-895198-86-7 .
- OECD : Screening Information Dataset (SIDS) Initial Assessment Report (SIAR) for Metilox , accessed on June 15, 2018.
- Patent US3364250 : Methyl β- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate. Applied October 22, 1965 , published January 16, 1968 , Applicant: Geigy Corp., Inventor: M. Dexter, EA Meier.
- Entry on Methyl 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate at Toronto Research Chemicals , accessed October 1, 2018 ( PDF ).
- fluorochem: MSDS Methyl 3- (3,5-di-tert-butyl-4-hydroxyphenyl) -propionate , accessed June 25, 2018.
- Patent US7985871B2 : Preparation of tetrakis [3 (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxymethyl] methane. Filed August 6, 2009 , published July 26, 2011 , applicant: Chemtura Corp., inventor: JS Hill.
- Patent US4594444 : Process for the preparation of sterically hindered hydroxyphenylcarboxylic acid esters. Applied on December 12, 1984 , published June 10, 1986 , applicant: Ciba-Geigy Corp., inventor: I. Orban.
- Patent EP0808818A1 : Process for the preparation of substituted hydroxy-hydrocinnamate esters. Applied on May 16, 1997 , published November 26, 1997 , Applicant: Ciba Specialty Chemicals Holding Inc., Inventors: ME Schultz, B. Dubuis, P. Küng, JR Ross.
- Patent US3677965 : Alkylhydroxyphenyl polyamides as antioxidants. Applied on December 29, 1967 , published July 18, 1972 , Applicants: Geigy Corp., Inventors: M. Dexter, B. Manor, JD Spivack, DH Steinberg.