The method of obtaining betulin

 

(57) Abstract:

Usage: in the medical, chemical and perfume industries. The inventive product betulin formula 1 is obtained from the bark of the birch, pre-activated in conditions pisabarro of paratrechina with the following parameters: pressure 2-5 MPa, temperature 180-260^oWith aging 60-360 C. the Structure of the compounds of formula 1 are provided in the text of the description. table 1.

The invention relates to extraction of valuable chemicals from waste wood, namely the method of obtaining betulin formula 1 from birch bark used in medicine and perfumery industry [1]

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Known methods of obtaining betulin, namely, that the bark is then ground in aqueous alkali and extracted with isopropyl alcohol. The output of betulin 26% by weight of the dry bursty [2]

During vacuum distillation of the dry alkaline hydrolysate at 230-245^oAnd a residual pressure of 10-14 mm RT.article the output of betulin amounted to 20% [3]

The closest technological essence and the achieved result is a way to handle birch bark aqueous alkali solution and extraction with isopropyl alcohol, the output betlog product (up to 26% by weight of the dry bark or not more than 60% of its content in bark), the low quality of betulin (in all cases betulin turns gray or yellow and is not given its melting point), the duration of the retrieval operations and consequently, the low efficiency of the process.

Shredding bark in one alkali solution is complex in terms of technology and requires high energy costs.

The aim of the invention is to simplify the process technology, increasing output and improving the quality of the target product.

The proposed method is that technological bark previously subjected to activation conditions pisabarro of paratrechina commonly used for activation wood chips [5] Naysabury precracking conduct: pressure 2-5 MPa, temperature 180-260^oC, the exposure time 60-360 C. When the bark is loosened in the dust and at the same time is the hydrolysis of weak bonds in the macromolecular structure of organic matter.

Bark after activation boiled in aqueous alcoholic alkali solution for 10-15 minutes, separating the solution from which distilled alcohol, the resulting solution was diluted with water. Fallen in sediment betulin is separated by filtration.

We offer akim output and better quality of birch bark, pre-activated in conditions pisabarro of paratrechina. The proposed method activation bark for these purposes has not been previously used.

Example. To 3 g of birch bark birch subjected to activation conditions pisabarro of paratrechina (pressure of 3.4 MPa, temperature 240^oC, hold time is 180 (C) with a humidity of up to 1% add 40 ml of water, 20 g of sodium hydroxide and 60 ml of ethanol and boiled in a flask with reflux condenser for 15 minutes the Solution is separated by filtration, distilled alcohol, the residue is diluted with 50-60 ml of water. Fallen betulin is filtered off, washed on the filter with hot water, dried. Exit 37% by weight of the absolutely dry bark (see table).

Optimal conditions for pisabarro of paratrechina: pressure of 3.4 MPa, temperature 240^oC, activation time, depending on the age and size of wood chips bark can vary from 60 to 360 C. the activation of the crust under lower pressure and temperature is impractical, because to achieve a good loosening and hydrolysis of birch bark requires a long exposure time, which reduces the intensity of the entire process of obtaining betulin.

Betulin by a known method is obtained with a yield of 12% of the PR CLASS="ptx2">

The proposed method betulin is obtained with the yield up to 37% by weight of the absolutely dry bark and is a white powder with so pl. 250-251^oC, known from the literature so pl. 251-252^oC [6]

The method of obtaining betulin formula

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from birch bark by extraction in aqueous alcoholic alkaline medium, characterized in that the bark is pre-incubated at 180 260^oC, 2 5 MPa for 60 360 C.