DE654393C - Process for the production of benzoyl caseins - Google Patents

Description

Process for the preparation of benzoyl caseins It has been found that one can benzoylate casein in a convenient way if one is on in concentrated solutions Casein dispersed by neutral alkali salts in the presence of alkaline ones Allow alkali salts benzoyl chloride to act.

The weight ratios of the starting materials can be within wide limits modified «to earth. You can also carry out the reaction at a higher or lower temperature carry out, with higher benzoylated products usually at a higher temperature can be obtained than at a lower temperature. That also plays an important role Degree of distribution of the casein. So you get z. B. all other things being equal with different degrees of division, products that are benzoylated to different degrees. Thus, as you wish, you can go from gritty, flour-like or dust-like or start from the finest wind-sighted casein.

Derivatives of proteins have already been made by acylating or alkylating them. The methods used up to now, such as acylation in the presence of aqueous media in which the proteins were dissolved (cf. Hoppe-Seiler, Zeitschrift für Physiologische Chemie, Vol. 88 [19i31, p.286 and 322, and Zeitschrift für Physiologische Chemie, Vol. 165 [1927], p.279), have the disadvantage of requiring large excesses of acylating agents and giving poor yields. The new procedure leads smoothly and in a simple manner to the desired casein derivatives without the use of large excesses of acylating agents. Depending on the amount of benzoyl chloride used, degrees of benzoylation of up to 15 % (determined as the benzoic acid which can be split off) can be achieved.

The benzoyl casein is said to be used for a wide variety of technical purposes, in particular for the production of plastics.

Example ii 50 parts of sodium carbonate are stirred in 1,000 parts of cold, saturated sodium chloride solution. Then, at room temperature, sprinkle 250 parts of as finely ground casein as possible into the salt solution and stir the mixture for 3 to 4 hours, giving a pulpy mass in which the casein is present in swollen form. Then zoo parts of benzoyl chloride are allowed to flow in over the course of 3 to 4 hours and the temperature of the mixture is kept within 20 ° to 30 °. The reaction mixture is then stirred for about another hour, ie until a sample of the casein has become insoluble in dilute sodium carbonate solution. Then tvi, approx the benzoylated product filtered off, with% v iel Washed in cold water and if possible dried at low temperature. The .e tene benzoylated casein may still be required from admixtures of casein and zoic acid can be purified by treatment with dilute aqueous sodium carbonate solution and then with water. The product forms a sandy powder that is insoluble in water, even in the presence of alkalis. The amount of sodium chloride used can be changed to a large extent. The degree of benzoylation can also be largely changed by changing the amount of benzoyl chloride used. The cold saturated sodium chloride solution can be replaced by that of sodium sulfate. EXAMPLE 2 25 parts of finely powdered lactic acid casein are sprinkled into 120 parts of saturated sodium chloride solution in which 15 parts of sodium carbonate have been stirred, and the mixture is stirred for some time until it is in a swollen form. 6 parts of benzoyl chloride are then allowed to flow in over the course of 3 to 4 hours, the reaction mixture being kept at a temperature of 20 ° to 25 °. The mass is stirred for a further 1 to 2 hours and the product is then filtered. To remove the added inorganic salts, the benzoylated mass is introduced into weakly acidic water, stirred until no further evolution of gas can be detected, the aqueous layer is separated from the precipitate by filtration, washed neutral and the benzoylated product is dried at the lowest possible temperature. If necessary, it is extracted with alcohol or ether to remove small amounts of added benzoic acid. A sandy powder is obtained which is insoluble in water and contains about 6% bound berizoic acid.

Example 3: -8o g of sodium carbonate become more saturated in 8oo ccm Stirring sodium chloride solution; then casein is sprinkled at 55 ° 1309. After four hours Stirring at this temperature, Ios g of benzoyl chloride are added dropwise over the course of 3 hours. When everything is mixed, stirring is continued for another hour at 50 ° and after that Sucked off cooling to room temperature. The sandy precipitate will be four more times Stirred with 2.5 liters of water for 15 minutes and decanted. It weighs after drying 8o g at 5o ° in a vacuum and is a pure white powder. Benzoic acid content: Example 4 450 ccm of saturated potassium sulfate solution are mixed with 2Io g of crystallized Stirred trisodium phosphate and after adding 50 g of casein for 20 hours Held 35 °. Then within q. Hours 10 g of benzoyl chloride was added dropwise. To stirring for a further two hours at 40 °, the mixture is cooled and filtered. The sandy, weak one yellowish precipitate is purified and dried as above. It weighs 43g. Salary Benzoic acid: 3.1%.

Claims (1)

PATRNTANSPRUCI3: Process for the production of benzoyl caseins, thereby characterized that one - on in concentrated aqueous solutions of neutral Casein dispersed in alkali salts in the presence of alkaline agents benzoyl chloride can be @ virken.