DE921327C - Process for the preparation of alkylsulfuric acid salts of imido ethers - Google Patents

Description

Process for the production of alkyfischulfur acid salts of imido ethers It has been found that alkylsulfuric acid salts of imido ethers are obtained if one carboxamides which contain at least one hydrogen atom in the amide group, in the absence of or in the presence of only small amounts of solvents, expedient at elevated temperature, reacts with dialkyl sulfates.

It is known that imido ethers can be obtained from aromatic and aliphatic nitriles by treating their alcoholic solutions with hydrochloric acid (Pinner: "The imino ethers and their derivatives" [1892 ]). In addition, Bühner (Liebigs Ann. Chem. 333, p. 292) prepared methylsulfuric acid imidoether from low molecular weight acid amides such as benzamide, methylbenzamide and acetanilide by boiling the benzene solution with 11/2 moles of dialkyl sulfate. According to Bühner, the reaction of 1 mole of benzamide with 1.5 moles of dimethyl sulfate in a benzene solution gives 89% of a crude product which, on reprecipitation, gives a product with losses which melts at lob to iii °. According to the present process, about 90 o / o of a product with a melting point of 118 '°' is obtained directly from benzamide. The process according to the invention therefore represents a technical advance, especially when working with higher molecular weight carboxamides.

According to the invention one works without a solvent or only with a small amount Amounts of solvents, when it comes to the melting point of high melting point To degrade substances. In most cases it is not necessary to have one To use excess dialkyl sulfate. The manufacture of the salts of the imido ethers becomes advantageous according to the present process so carried out that the liquid or molten carboxylic acid amides or those by a small, but inadequate addition of solvents to liquefied carboxamides treated at elevated temperature with dialkyl sulfate in approximately molar quantities for so long until the products have become water-soluble. In certain cases it can be useful be to use a deficit of dialkyl sulfate. A mixture is then obtained on imido ethers with unchanged carboxylic acid amide. Complete water solubility occurs naturally not one.

Carboxylic acid amides, those on nitrogen, are suitable as starting materials carry at least i free hydrogen atom, z. B. those in the amide group, if appropriate monosubstituted amides of resin acids, naphthenic acids, fatty acids, or of substituted Carboxylic acids, e.g. B. of chlorinated or phenylated fatty acids. As a substituent in the amide group, for example, alkyl groups, oxalkyl groups or polyglycol ether groups can be used to serve. As dialkyl sulfates, for example, dimethyl sulfate, diethyl sulfate and the like. a. into consideration. The process can be carried out at room temperature or at an elevated temperature to 2oo ° are carried out, the reaction time largely depending on the temperature depends. It proves to be expedient to add in the temperature range from 8o to 100 ' work, on the one hand to accelerate the course of the reaction and on the other hand bright Products to receive.

The salts of imido ethers obtained according to the invention are partly crystallized substances, partly waxy to oily substances. The products can be used with advantage as such or after their treatment with alkali or organic bases, possibly in the presence of solvents, in the textile industry or in the production of synthetic fibers. Example i 211 g of coconut fatty acid amide (1 mol) and 126 g of dimethyl sulfate (1 mol) are heated to 80 °. The reaction starts after a short time with a significant increase in temperature. After a few minutes, the product dissolves clearly in water, producing a well-foaming solution. 330 g of a red-brown oil are obtained. If the reaction is carried out in boiling benzene according to Bühner's method, a dark-colored product with unsatisfactory properties is obtained when the benzene is distilled off in vacuo at an elevated temperature. Example e 30.2 g of benzamide (0.252 mol) are mixed with β g of benzene and heated to 80 ° with 47.4 g of diethyl sulfate (0.38 mol) and converted into a benzene-free melt by distilling off the benzene in vacuo at 80 ° . By placing the melt in a desiccator over concentrated sulfuric acid, crystals are obtained after a few hours which, after rubbing with a little ether and suction, give 55 g of the methylsulfuric acid salt of the imidoether formed with a melting point of 118 °. Yield 89.5% of theory. The product can be obtained in the same purity if one works with molar amounts of dimethyl sulfate in the absence of benzene.

Example 3, Ulan drops 1 mole of dimethyl sulfate at 150 ° in a few minutes to 1 mole of coconut fatty acid ethanolamide. During the reaction, distill in descending order 8 g of methanol over the cooler. After briefly stirring at 150 to 160 °, a brown oil, which gives a good foaming solution when completely soluble in water, shows the acidic reaction. The imino ether separates from these solutions when added of lye. If the same reaction is carried out at 80 to 100 ° in 75 minutes, so you get a lighter product with otherwise the same properties. Example 4 i Mol Coconut fatty acid ethanolamide, which with the addition of 0.5% alkali at 125 ° with 2 mol Ethylene oxide has been pretreated, is reacted at 7o to 75 ° `with 1 mole of dimethyl sulfate. A brown water-soluble oil is obtained. When using stearic acid ethanolamide instead of coconut fatty acid amide, waxy products are obtained in some cases.

Example 1 mole of lauric acidethanolamide is treated with 1 mole of dimethyl sulfate at 90 ° to 95 ° for 8 hours (at the end in vacuo). During the reaction, 39 methanol distilled off on the descending condenser. On cooling, a slightly colored product of waxy consistency is obtained. It dissolves clearly in water and gives good foaming solutions which, when soda solution is added, result in a precipitate. Under the same experimental conditions, oleic acid ethanolamide can be treated with molar amounts of dimethyl sulfate and a brown oil is obtained. EXAMPLE 6 1 mole of coconut fatty acid ethanolamide is treated with 10 moles of ethylene oxide at 10 ° with the addition of 1.5% caustic soda and then reacted with 1 mole of dimethyl sulfate at 70 to 75 °. The dark brown oil is clearly soluble in water. The foaming aqueous solution gives no precipitation after the addition of alkali. When using stearic acidethanolamide, some waxy products are obtained by the same procedure. If oleic acid ethanolamide is treated with the addition of 0.5% caustic soda at 120 ° with 12 mol of ethylene oxide and reacted with 1 mol of dimethyl sulfate, a clear, water-soluble brown oil is obtained.

Example ? ioi g oleic acid ethanolamide (0.3i mol) are at 9o to ioo ° 55 minutes with 15.7 g of dimethyl sulfate (o, 125 mol) implemented and 8 Hours at 90 to 100 ° 'stirred in vacuo. 116 g of a brown colored one are obtained 151s, which still contains unchanged oleic acid ethanolamide.

Claims (2)

PATENT CLAIMS: i. Process for the production of alkyl sulfuric acids Salts of imido ethers, characterized in that carboxamides which are in of the amide group contain at least i hydrogen atom, in the absence of or in the presence of only small amounts of solvents, expediently at elevated temperature, with dialkyl sulfates. 2. The method according to claim i, characterized in that that approximately equimolar amounts of the starting materials are used.