CS237195B1 - A method for isolating a lanolin alcohol moiety from hydrolyzed lanolin - Google Patents

Abstract

The invention relates to a method of isolating the lanolin alcohol fraction from technical or crude lanolin, after hydrolysis with an aqueous solution of sodium hydroxide at the boiling point of the reaction mixture to form sodium soaps, which are isolated and extracted in the solid state with acetone or ethyl acetate; the extract residue is processed in a known manner to obtain crude cholesterol, which is an important starting material in the pharmaceutical and cosmetic industries.

Description

The present invention relates to a process for the isolation of a lanolin alcohol moiety from lanolin of varying degrees of purity after sodium hydroxide hydrolysis based on solid-liquid extraction. Lanolin, obtained in large quantities from wool laundering wastewater, is currently the most promising source of cholesterol, an important raw material for the pharmaceutical and chemical industries. Cholesterol is used, for example, in the manufacture of certain drugs of steroid structure, vitamin cholecalciferol, ointment bases, emulsifiers, etc.

Isolation of cholesterol from lanolin has been extensively studied for many years and various procedures have been the subject of numerous patents and other publications. A number of references are summarized in some works (eg Elsevier Encyclopaedia of Organic Chemistry, Volume 14-Supplement, Elsevier Publishing Company, Amsterdam, 1954, pp _. 1580s to 1581s); Synthesis of Pardubice-Semtín 1973; Schwarz et al.: 231 912 There are known work using microbiological and enzymatic processes for the processing of lanolin (Japan Ko.kai 7 301 184, 7 301 185) 7 303 393), but in most cases it is isolation of cholesterol based on several successive chemical operations: lanolin hydrolysis, extraction of lanolinal alcohol fraction, isolation of crude cholesterol from lanolinal alcohol fraction, purification of raw cholesterol. The published procedures differ in the different working conditions of the individual lanolin processing operations.

Alkaline hydrolysis of lanolin yields a mixture of lanolinic acid salts and a cholesterol-containing lanolin-alcohol moiety in addition to a number of other neutral substances. Isolation of the lanolin-alkaloid portion is therefore a key operation. The alkaline hydrolysis is generally carried out with potassium hydroxide or sodium hydroxide in water

237 195 of an alcoholic or aqueous solution (see above for quotations) and extraction of the lanolin alcohol moiety is generally performed by a liquid-liquid system. This procedure is used by the vast majority of authors, not only after hydrolysis with potassium hydroxide, where extraction of this type is only possible, but also after hydrolysis with sodium hydroxide, where the resulting sodium soaps can be prepared in a solid state. There is a known procedure whereby lanolin is extracted after hydrolysis with sodium hydroxide from aqueous ethanol solution (BIOS 1581.4) or ethanol solution (Niewiadomski et al .: Przemysl Chemiczny 44. 213, 1965). hydrolysis with sodium hydroxide in aqueous isopropyl alcohol, followed by countercurrent melt extraction after hydrolysis with gasoline (US patent 2,619,495). Also described is the hydrolysis of lanolin with aqueous ethanolic sodium hydroxide, followed by neutralization with acid sulfuric acid; isolation of the lanolin alcohols is accomplished by precipitation of sodium salts in excess acetone (Brabenec; Internal Report of VÚOS S.37, 1960). Solid-liquid extraction is described in US Patent 2,579,986; the process is based on the hydrolysis of lanolin with sodium hydroxide and the conversion of sodium soaps to calcium, which are then extracted with acetone. Also Belgian patent 816,235 describes the conversion of sodium soaps to calcium, which under certain conditions is separated from the lanolinal alcohol fraction. However, these processes require a further operation, i.e., converting the sodium soaps to calcium by calcium chloride. The usual liquid-liquid operation is very demanding. Its success depends strictly on the ratio of water-alcohol or water-alcohol. % aqueous solution of hydrolyzed lanolin and water-immiscible solvent, the ratio being varied with lanolin composition, temperature, extraction speed, etc., and there is always the risk of forming inseparable emulsions. Liquid extraction

- the liquid further requires significant volumes of extraction solvents or the use of efficient but costly devices such as countercurrent column extraction

The above disadvantages are eliminated by the process of isolating the lanolin alcohol moiety from industrial or crude lanolin after hydrolysis with aqueous sodium hydroxide solution at the boiling point of the reaction mixture to form sodium soaps according to the invention, which consists in extracting solid sodium soaps in solid state liquid with acetone or ethylacetate and the extract is worked up to a lanolinal alcohol fraction. Cholesterol is obtained from this fraction in a known manner. 3,237,195 is based on the hydrolysis of lanolin with an aqueous solution of sodium hydroxide at elevated temperature. Drying yields solid sodium soaps which, after crushing, are extracted in a Soxhlet extractor or other similar device. Acetone or ethyl acetate is preferably used as the extraction solvent, while other organic solvents such as aliphatic or aromatic hydrocarbons, chlorinated solvents and alcohols do not give good results »Evaporation of the extraction solvent yields a high-cholesterol lanolinal alcohol fraction from which is then isolated cholesterol by any of the known methods, for example by forming an adduct with zinc chloride, decomposing the adduct with water to produce crude cholesterol and crystallizing it from methanol, thereby obtaining highly pure cholesterol (Schwarz et al.): AO 231 912 neutralization of extracted sodium soaps and further isolation of neutral waste after formation of adduct with zinc chloride or after crystallization of raw cholesterol, ie raw materials with potential use in chemical industry, for example »in the production of surfactants»

The following examples illustrate the invention but do not limit it.

Example 1

500 g of molten technical lanolin is hydrolysed by boiling with 75 g of sodium hydroxide in 500 ml of water for 6 hours. After cooling the mixture to 6 ° C, 120 g of sodium chloride are added and the mixture is allowed to stand for 16 hours at 22 ° C. The sodium soaps were separated and dried at 50-55 ° C to constant weight (573 g).

500 g of sodium soaps are extracted in a Soxhlet extractor with 3 liters of acetone for 4 hours. The acetone extract was evaporated to dryness, yielding a 221 g lanolin alcohol content containing 33.5% cholesterol (OLO). The lanolin alcohol fraction was dissolved in 1.1 liters of benzene, water residues were distilled off azeotropically, 55 g of anhydrous zinc chloride were added and the sieve was boiled for 1 hour. After cooling to 30 DEG C., the precipitated calcium chloride addition compound is suction filtered, washed with benzene, dried and quenched with 400 ml of water. The precipitated crude cholesterol is filtered off with suction, washed, dried and crystallized from methanol. 22.7 g of I. product, m.p. 145-147, are obtained

The mother liquors are worked up

4 7.5 g of the II. Product, m.p. 143-145 ° C. 237 195

Example 2

The procedure of Example 1, but using 500 g of crude lanolin and extracted with an equal volume of ethyl acetate Workup as in Example 1, a total of 24.3 g of cholesterol, mp 143-146 DEG C. _e

Claims (1)

OBJECT OF THE INVENTION 237 195 Process for the isolation of a lanolinalcoholic portion from lanolin of technical or crude, after hydrolysis with aqueous sodium hydroxide solution at the boiling point of the reaction mixture to form sodium soaps, characterized in that the solid sodium soaps are extracted with solid-liquid acetone or ethyl acetate and extract is sprayed onto the lanolin alcohol moiety.