SU362000A1 - - Google Patents

Description

(54) METHOD FOR OBTAINING MQHO - AND DIALDEHYDES

one

The invention relates to the field of petrochemical synthesis, in particular, to methods for the treatment of aliphatic mono- and dialdehydes.

Aldehydes are semi-products for the synthesis of alcohols, acids, eph1fs, etc.

A known method of producing aldehydes, including dialdehydes, consists in ozonizing the corresponding olefins or cycloolefins, followed by hydrogenation of the ozone products obtained on a palladium catalyst. The disadvantages of this method are the lack of view selectivity as a result of the side reaction of formation of acids and. accordingly, low yields of the target product (60-70% of theory).

In order to increase the selectivity of the process and increase the yield of the target product, the platinum catalyst and the ved1 / t process in the active solvent medium are used as the catalyst for hydrogenation.

The starting bead - the appropriate olefinic hydrocarbon or mixture of hydrocarbons - is ozonated in the medium

aliphatic alcohol or mono-carboxylic fatty acid C2-. With the way

bubbling through a solution of ozone-containing gas with an ozone concentration of 2–5%. The choice of one or another solvent is determined by technological considerations.

The resulting ozonisate without prior separation is subjected to hydrogenation

in the presence of platinum catalysts at a temperature of about-5 ° C and a hydrogen pressure of 1-5 atm. The use of a solvent reduces the amount of by-products.

The resulting aldehydes are isolated from the solution by any method or else they are subjected to further conversion into alcohols or amines by known methods in the same solvent without prior isolation.

The latter method is more preferable with respect to dialdehydes, which, when isolated, are easily polymerized.

Example 1. 10 g of dodecene in a solution of 40 ml of undepshtyl alcohol is subjected to ozo tsirovaniyu iiyrt M barotene through a variety of ozonated air containing 2% of Osyun, to the amount of ozone in the exhaust gas. The obtained ozonisate without pretreatment is subjected to hydrogenation with hydrogen in the presence of catalyst Pi 02 at atmospheric pressure and at TeMnepaiyre. Hydrogenation absorbs 1300 ml of hydrogen. After separation of the catalyst, the hydrogenate is washed three times with hot () water. The wash water contains 2.1 g of formaldehyde (89% of acacia), and the washed hydrogenate contains 9.6 g (96% of theory) of undecyldehyde (according to GLC analysis). Example 2. 11 g of Csschoschen in a solution of 5 O ml of n-butanol is ozonated by bubbling through a solution of oxygen containing 5% ozone until ozone appears in the waste gas. The obtained ozonisate is hydrogenated without pretreatment in the presence of 1 g of catalyst with 5% platinum on SSC silica gel at atmospheric pressure and at temperature. 2.2 p of hydrogen is absorbed (96% of theory), the hydrogenate is subjected to va; distillation at a residual pressure of 2. Art. 13.4 g of 1.8 hexanded is obtained with a carbonyl number of 778 mg KOH / g (theoretical 785). The output of the theory is 92%. Example 3, 8 g of cyclododecene in rastonate 4O ml of glacial acetic acid is ozonated at room temperature ui uiiii (with oxygen containing 5% ozone) until ozone appears in the exhaust gas. Ozonisate is hydrogenated in an autoclave under hydrogen pressure 5 atm at room temperature in the presence of 0, 5 g of catalyst 5 / o P on silica gel SSC. After separation of the catalyst, the hydrogenate is rectified at a residual pressure of 2 mm Hg. After 30 ml of acetic acid, the residue is washed with water until neutral in water. exist under vacuum After that, 8.9 g of 1.10 dodecandial with a carbonyl number of 550 mg KOH / g (theoretical 565 MI KOH / g) is obtained. The yield is 85% of the theoretical gain. Subject 1. Method of elimination mono- and donaldegady ozonization of olefins in a polar solvent, for example aliphatic alcohol, followed by hydrogenation of the ozonation products in the presence of a catalyst and the division of the target product with known methods, in order to increase the yield of the target product and se- lecture process, as a catalyst for hydrogenation of Root Plain Kata Visitors. 2, a method according to claim 1, characterized in that, in order to reduce the formation of by-products, rHAjjapoBauHe is carried out in a polar solvent, such as aliphatic alcohol.