SU1057488A1 - Process for preparing 3-n-mentene - Google Patents

Abstract

METHOD OF PREPARING THE P-MENTENA by catalytic isomerization of karan at 20-80 ° C, characterized in that, in order to increase the yield of the target product and simplify the process technology, a Y-zeolite containing 1-10 wt.% Is used as a catalyst. dysprosium or 0.7-1.0 wt.% copper in an amount of 3-10% by weight of karana-.

Description

O1

u4

QO

ace

The invention relates to a process for the preparation of 3-p-mentene, which is the raw material for the synthesis of mengol. The latter is widely used in various industries, including cosmetic, food, pharmaceutical. At present, the production of menthol in our country. does not have a sufficiently reliable resource base. The need for menthol is many times greater than its capabilities. obtaining from peppermint essential oil - the only natural raw material in the USSR for the production of menthol. .

From here: the ways to obtain 3-pentene from CL and / J-pinenes or pinen-containing raw materials are concluded that they are isomerized in the presence of strong acids in p-mentadienes. Didenten, terpinol, Ieoterrinol, os and u-terpinenes, n-ment-3,8g-diene, with an admixture of fenhenor and n, -zigloll are formed. Further, the mixture of ... mentadienes 1. is disproportioned and partially hydrogenated in the presence of hydrogenation catalysts, for example palladium, Yargum Rene, nickel formate, etc., resulting in hydrogenation, in one double way, with the formation of a menten mixture. Fractional: 3-PG-1 and 2 were isolated by race.

The disadvantage of these methods is the low selectivity of the process and the low yield of the desired 3-p-mentene.

The method of producing 3-p-mentene by selective hydrogenation of non-conjugated p-mentadienes, one of whose double bonds is in position 4 (8 J or 8 (91, in the presence of a complex compound of ruthenium as a catalyst), is known. Hydrogenation is obtained. the reaction mixture containing up to 68-70% of the target 3-p-mentenase GZ J.

The closest in technical essence to the present invention is a method for producing 3-p-mentene by cataytic isomerization of quarantine. This method involves contacting the Qaran with a dilute strong acid at 20-11 s. As a catalyst in the known

The method uses inorganic acids, for example sulfuric, phosphoric, hydrochloric, as well as organic acids, for example oxalic, acetic, chloroacetic and other acids, which under the reaction conditions are not oxidizing and are comparable in strength to acetic acid G40.

A disadvantage of the known method for the preparation of 3-p-mentene is the use of inorganic and organic acids as a catalyst. Under these conditions, the reaction proceeds in two directions: with the formation of a mixture of isomeric P-mentenes up to 65% and mixed-mentenes up to 33%, which are impurities. In addition, the reaction is complicated by polymerization (up to 20%.}, A special purification of the target product is required. All this significantly reduces the output of 3-p-mentene, which is 55%, according to GLC and 36.8%, from It requires the use of a large amount of acid, the ratio of karan: acid is 1: (1-3 b Acids are not regenerated, which leads to a waste water run-up. To implement an existing system; not exposed

to the action of acids.

The purpose of the invention is to increase the yield of the target product and simplify the process technology.

The goal is achieved

In addition, according to the method of obtaining 3-p-ment by catalytic isomerization of caran at 20–80 s, a Y-type zeolite containing 1–10 May is used as a catalyst. dysprosium or 6.7-1.0 wt.% copper, in an amount of 3-10% by weight of karan.

As a catalyst in the proposed method, the industrial catalyst Tse.ocar-2 (TU-38-10233-7 L) can be used predominantly. To carry out the process, the quaran and the corresponding zeolite catalyst are heated at 2p-80 ° C for 1-3. h. The yield of the target product reaches 60.6% of the initial quarantine.

The chemical nature of the occurring PE process can be represented by the following scheme: Catalyst 20-80 C t A T l l L; L Example 1. 138 g of quarantine and 6.9 g (5% of the mass of quarantine of a zeolite of type Y containing 1% by weight of dissolution is heated under reflux by nickname for 3 hours. The reaction product is separated from catalysis). 130.9 g (94.9%) of isomerizate are obtained, containing, according to GLC analysis, 72.2% of the 3-p-mentena. By distillation on a 60 t column, 76.5 g (54.5%) are obtained. , 8% of the initial tselenoprodukta.Tp. Bp 168-169 ° / / 760 mm Hg 1.4525, d 0.81.30. Found,%: C 86.89; H 13.11. - 1-8% is defined,%: C 86.96; H 13.04. EXAMPLE 2 Differs from example 1 in that the reaction is carried out in the presence of 6.9 g (5% by weight of quarantine) zeolite -type Y, containing 5. wt.% dysprosium for 2 hours. The yield of 3-p-mentene is "83.6 g (60.6%). The product has the same constants. Example 3. Differs from example 1 by the fact that the reaction is carried out in the presence of a type-Y zeolite containing 10% by weight of dysprosium for 1.5 hours. The yield of the target product is 81.0 g (58.7%. The product has the same constants. Example 4. Differs from example .1 in that the reaction is carried out in the presence of 13.8 g (10% by weight of quarantine) type Y zeolite containing 0.7 wt.% Copper for 3 hours. The yield of the target product is 71.3 (51.7%). The product has the same constants. . . Example 5. It differs from Example 4 in that the reaction is carried out in the presence of a Y-type zeolite containing 0.9% by weight of copper at 50 ° C for 3 hours. The yield of the desired product is 81.8 g (59, 3%). The product has the same constants. Example 6. It differs from Example 4 in that the reaction is carried out in the presence of a Y-type zeolite containing 1.0% by weight of copper at 70 ° C for 2 hours. The yield of the 3n-mentena was 82.9 g (60.1%). Products have the same constants. Example 7. h. 38 g of quarantine and 4.2 g (3% of the mass .. apfi.Ha) of zeolite Tseokar-2 (TU-38 -10233-71) are heated under reflux for 2 hours, and the rest under the same conditions as in example 1. I obtain 132.5 g of nzomerizate containing, according to GLC, 72.8% of the Gn-menten. By rectification of the isomeriate, 80.3 (52.8% per quarantined) of the target Product was isolated. The product has CBN stanta given in Example 1. Example B. Differs from Example 7 in that the reaction is carried out with 6.9 g (5% of the mass of quarantine) of Zeolar-2 zeolite at 50 ° C for 3 h. The yield of the target product is 83.3 g (60.4% of the initial). The product has the same constants. Example 9. It differs from Example 7 in that the reaction is carried out with 13.8 g (10% of the mass of the quarantine) of Zeolit-2 Zeolite at a temperature of 20 ° C for 3 hours. The yield of the target product is 82.8 (60.0%). The product has the constants given in example 1. EXAMPLE 10 - conditions of the prototype. 175 h karana and. .350 h 50% heat at boiling (105 ° C) for 7 h. The reaction product is washed with water (3; 200 ml) with 5% soda solution and again with water until neutral. Dried. After distillation, dissolve. The bodies are obtained a dark brown product, which is dispersed in vacuo. A fraction of hydrocarbons of 107f 6 g (78%) is obtained, which, according to GLC, contains 55% of the Z-p-mentene and polymers 38.5 g (22%). By rectification of the fraction. And hydrocarbons, 50.7 gg (36.8%) of the desired product is obtained. 1.4538. Bp 167-169, 0.8147. Found,%: C 86.87; H 13.13. C-H g. Calculated,%: C, 86.96; H, 13.04. The use of the proposed method of obtaining Zn-mentene from karana provides a number of advantages compared with existing methods. As a catalyst, type-V zeolites modified with rare-earth or transition metals are used, which makes it possible to increase the selectivity of the process, minimize the polymerization reaction, eliminate special treatment of the reaction product. All this allows to increase the yield of the target product by 23% compared with the prototype. The advantage of the proposed method is the fact that the industrial zeolite Deocar-2 can be used as a catalyst. However, the yield of the target product does not decrease. In the existing method used in. as a catalyst, inorganic and organic acids, which leads to the formation of a mixture of hydrocarbons P- and m-mentene, in a ratio of about 2: 1. The reaction is complicated by polymerization (20%). special cleaning of the target product is required; the output of which does not exceed 36.8%. from the original karana. In the proposed method, the catalysts are used in a small amount, since they are highly active. The reaction proceeds with the use of a catalyst in the amount of 3-10% by weight of karan, preferably 5%. With increasing amount of catalyst proceeds the process of polymerization, which reduces the yield of the target product. In the existing method, the acids are used in large quantities - 100-300% by weight of karan. The catalyst is easily regenerated, has a long period of action, S10574886

does not corrode hardware. In essence, a special procedure is required by the acidic acid method. It is not a regeneration apparatus that is not exposed, which would lead to contamination by the action of acids.

Claims (1)

METHOD FOR PRODUCING 3-P-MENTHENE by catalytic isomerization of karan at 20-80 ° C, characterized in that, in order to increase the yield of the target product and simplify the process technology, ceo is used as a catalyst. type lithium containing 1-10 ’wt.% dysprosium or 0.7-1.0 wt.% copper in an amount of 3-10% by weight of the quran. SL • M 105/488