SU395351A1 - WAY OF OBTAINING 2,6-DI-HN? G-BUTYL-4-METHOXYMETHYLPHENOL - Google Patents

Description

one

The invention relates to methods for the preparation of 2,6-di-greg-butyl-4-methoxy-imethyl Nol - a polyester dyes antioxidant, lubricating oils, etc.

A known method for the preparation of this antioxidant in the form of 2,6-D1I-Greg-but1 ILPhenol with Pharmaldegve and methaNol in the presence of alkali. Along with the implementation of the method, along with the main product, a side-product is obtained - 4,4-methylene-bis- (2,6 g; and-gre- (but 1 IL phenol). 5-SOVo. The resulting mixture causes, due to the impurity of the noi6o4 product, the ossification when introduced into the polymer. (2,6-di-gret-, butylfe: nola) in a mixture (usually 20-22Vo). The yield of the target product is 60-65o / of theory (without losses during purification).

The purpose of the present invention is to increase the yield and improve the quality of 2,6-di-greg-butyl-4-1-methoxy-1-methylphenol. To obtain this goal, the process is proposed to be carried out in the presence of an alkaline buffer, for example acetate, at a pH of 12.5-14.0.

The proposed method makes it possible to increase the yield of the target product to 80-BBO / o from a theoretical reduction in the course of an increase in the amount of side-produced 4,4-methylene-bis- (2,6-di-greg-butylphenol), the content of which in the target product is 1 -4 weight. / 0.

The use of recycled filtrate, as well as farmadin, methanol and a buffer catalyst reduces the consumption of reagents and eliminates the formation of phenolic wastewater.

P p i. e p 1. And with about 3 about in and p not a cetat a about about buffer.

I cycle. In a flask with a smeshalka. reverse cooler, ter, mol; rum, dropping funnel, equipped with water oine, load 475 ml of methanol, 9.1 g e1D1Kogo soda, 3.5 g of acetic acid and 50 ml of formalin. The mixture is heated to 60 ° C and with stirring in

a solution of 25.8 g of 2,6 di-greg-butylphenol in 25 ml of methanol is added over 30 minutes, then further maintained at 60 ° C for 30 minutes and cooled to 0 ° C. The precipitated crystals are filtered, the filtrate is used for

conducting the P cycle (after replenishing the consumed formalin p methanol). 20.6 g of crude 2,6-di-greg-butyl-4-methoxymethylphenol (theoretical yield) are obtained with t. 98.6-99 ° С (according to literary data, t. Pl. 100-101 ° С) containing less than

P / s 4,4 - M. methylene-bis- (2,6-1di-gu5eg-butylphenol).

II cycle. I cycle was carried out to the filtrate obtained, 15 ml of methanol and 8 ml of forms were added and the mixture was added to 60 ° C, and a solution of 25.8 g of 2,6-di-g / 7et-, butylphenol B 25 ml of methanol. The mass is additionally stirred at 60 ° C for 30 minutes, cooled to 0 ° C, the precipitated ise is filtered off, and the filtrate is used for carrying out cycle III. . 28.4 g of crude 2,6-di-tert-butyl-4-1-methoxymethyl | phenol (90.8Vo from the theoretical) are obtained with m. Pl. 97.4-98.6 ° C, containing less than 2% 4.4 - methylene-BDS- (2,6-d. And-t t7e-byb Ilfenol).

Iii. cycle. The filtrate obtained in the second cycle is also treated and 29.7 g of crude 2,6-d (util-4-metaxy-1-methylphenol {95.0 "/ o from theoretical η1) with m. Pl. 96.2-97.0 ° C, containing less than 3, 4,4-methylepys- (2,6-d | i-greg-butfilf0nola).

IV CYCLE. The filtrate obtained in the third cycle is treated in the same way as in cycle two. Obtain 29.8 g of crude 2,6-di-g / 7et-.butyl-4-methoxymethylphenol (95.3v / o from the theoretical) with m. 96-96,7 ° C, containing 01kol 4,4-methyl (Nb "c- (2,6-d-tert; butylphenol).

So | M oyrazam, in 4 cycles receive 105.2 g of the product (80, from theoretical).

When a part of methanol is removed from the filtrate, an additional 9.3 g of a crystalline product is isolated, after purification of which 6.2 g of its 2,6-D cheese is obtained (I-agreg-buti l-4 -1 meto1K cI | Meti lf en ol with mp. 97-97.4 ° C (containing 3, G / o 4.4-1 met1Ilei-bms- (2,6-DI-gret-1 butylphepol).

Taking into account the additionally allocated target product, its yield is 111.4 g, i.e. 85, from the theoretical. The crude product is 2,6-di-G; og-butyl-4-methoxymethylphenol, - (obtained in 4 cycles, it will contain on average about 3Vo 4.4-1-1-methylene-by- (2,6-dit / et- butylfavnola) without additional purification | Ki. With its introduction as IB as an antiacoid in polymers, the latter do not change color during the aging process.

Example 2. The use of phosphate buffer.

The reaction is carried out analogously to example 1, but acetic acid is replaced with 0.85 g of phosphoric acid (85 / o-1H).

In 4 cycles, 103.7 g of the intended product - 2,6-di-t / 7eg-butyl-4-metaxy-1-methylphenol (79.8% of the theoretical) are obtained, and taking into account the purified product additionally separated from the filtrate, 113.4 g , ie, 87.2 “/ o from theoretical. The crude product obtained in 4 cycles contains, on average, about 4 «/ about 4,4 methylene bis- (2,6-di-tert-butylphenol) without additional purification.

The filtrates that form after the last cycle, and used to separate some additional product, are distilled. The methanol is distilled off, which is returned to conduct the reaction, then the resin precipitate is separated, and the amount of 1LUODY that was separated during the reaction is distilled off from the aqueous layer, after which the aqueous layer containing form | Small n and the buffer catalyst are again used to carry out the reaction .

PREAMETE OF THE INVENTION

The method of obtaining 2,6-dp-g / 9r-bu11Il-4-methoxyxylphenol is possible by the interaction of 2,6-digreg-butylphenol with formaldepid and methanol in an alkaline medium (followed by separation of the target product by known methods, characterized by that, in order to capture the fruit of the target product and improve its quality, the process is carried out in the presence of an alkaline buffer, such as acetate, at pH 12.5-14.0.