SU857103A1 - Method of producing 2-methoxy-2,6-dimethyloctanol-7 - Google Patents

Description

(54) METHOD FOR OBTAINING 2-METOKCI-2,6-DI ffiTSHYUKTAHOLA-7

The invention relates to organic chemistry, in particular to the improvement of the method for producing 2-methoxy -2,6-dimethyloctanol-7, which has a santalum odor. It should be noted that the resources of natural sandalwood oil on the world market are very limited. Therefore, fragrances are of great value for perfumes. a smell similar to the smell of santal oil. The closest to the present invention is a method for producing 2-methoxy2, 6-dimethyl1octanol-7, consisting of three stages: a) addition of methyl alcohol to 2,6-dimethyloctadiene-2,7 (dihydromyrcene) in the presence of acid catalysts; b) epoxy of the resulting compound obtained in lots; c) restoration of the epoxy in the presence of skeletal nickel to the target product ll. However, the explosiveness of the epoxidation stage and the formation of aggressive wastewater, the use of ocean-nickel at the recovery stage, the low selectivity of recovery, and the low yield of the target product (60%) make it possible to widely use this method. The purpose of the invention is simplified in. process and amount of wastewater when receiving 2-methoxy-2,6-dimethyloctanol -7. The goal is achieved by the fact that according to the method for preparing 2-m-vtoxy-2, 6-da and m-1-yukhtanol-7 in one stage, namely by treating the unsaturated compound with methyl alcohol in the presence of acid catalysts, 2,6-dimethyloctane is used as the starting unsaturated compound : 2-ol-7. In addition, the process is carried out in the presence of an acid catalyst. taking in an amount of 0.03-2.5 mol per 1 mol of 2,6-dimethyloctane -2-ol 7. Strong inorganic — OR organic protic acids, such as concentrated sulfuric acid or p-toluenesulfonic acid, can be used as the acid catalysts, in the amount of 0.032.5 mol per 1 mol of elenol. When the amount of acid is less than 0.03 mol, the process proceeds too slowly, and the use of acid in the amount of more than 2.5 mol does not improve the process parameters and is therefore impractical. As an acid catalyst, it is also possible to use an ambient resin cation, for example, K5-23 in the H form, in an amount up to 35% by weight of the starting elenol. The initial molar ratio of elenol and methyl alcohol can vary from 1:10 to 1: 2.5. With a lack of methyl alcohol, the yield of the target product decreases, and an excess of methyl alcohol above 10: 1 does not improve the process parameters. The temperature range of the reaction lies in the range from 20 ° C to the boiling point of the reaction mass, which depends on the initial ratio of reagents, but does not exceed 75 ° C. At 20 ° C, the reaction proceeds almost irreversibly, but slowly, and therefore an excess of acid catalyst is required. up to 2.5 mol per 1 mol of ele el. The yield of the target product thus exceeds 90% according to GLC. Pr temperatures above 30 ° C establish an equilibrium. At a temperature, the ratio between the desired product and slenol is 65:35 at equilibrium (according to GLC). The equilibrium time decreases with an increase in the reaction temperature and the amount of acid, the equilibrium ratio indicated in the reaction mass at 70-75 ° C is reached in 6 hours with the use of 0.04 mol per 1 mol of the initial elenol. The ability to use such a small amount of acid to the talizator makes it possible to minimize and even completely eliminate waste water while neutralizing the reaction mass. Purification of the target product (82 C / 1 mm) from unreacted enool (batch mm) is carried out by 4 vacuum distillation and does not require high efficiency vacuum rectification. Unreacted elenol and methyl alcohol are recycled. The overall yield of the target methoxy alcohol is 90% of the theoretical one for the reacted elenol. Example 1. To a solution of 100 g (o, 64 mol) of 2,6-dimethyloken-2-ol-7 (slenol) in 71.7 g (2.24 mol) of methyl alcohol was added 2.6 g (0.026 mol) concentrated sulfuric acid and stirred for 7 hours at a boiling point of 72-73 ° C. The reaction mass is cooled to 30 ° C, neutralized with addition of 3 g (o, 0028 mol) of soda, the unreacted methyl alcohol is distilled off, the residue is filtered off from the salt precipitate and distilled into vacuum, giving 32.1 g of unreacted slenol and 71.9 g of 2-methoxy-2,6-dimethyloctanol-7 (elesant). Yield 60% of theoretical and 87.8% of reacted elenol. The resulting elenol and yeast alcohol are reused to obtain the eslesant. 2-Methoxy-2,6-dimethyloctanol-7 (elesant), T / 1 mm Hg, n |, ° 1.4458. Found,%: C 69.92; H 12.93 Calculated,%: C, 70.16; H 12.85, the IR spectrum confirms the structure of the target product. Example 2. Synthesis was carried out analogously to example 1, but the reaction mass was neutralized by adding 5.33 g of a 42% aqueous solution of caustic soda (0.056 mol), and then treated as indicated in example 1. The yield of ethanol was 61.5% of the theoretical for taken and 89% for reacted ele ol. Example 3. The synthesis is carried out similarly to examples 1 and 2, but the residue of the salts after neutralization is not filtered off, but vacuum distilled in the presence of a precipitate in a still tank. Elesant yield is 61% of the theoretical one taken and 90% of the reacted elenol. Example4. 22.4 g (0.13 mol) of para-toluene sulfonic acid (PTSA) was added to a solution of 100 g (0.64 mol) of maple of 204.8 g (6.4 mol) of methyl alcohol and stirred for i h at the boiling point 6768 ° C. The reaction mass is cooled until neutralized with the addition of 35 g (0.253 mol) of potash, the precipitate is filtered off, the excess methyl alcohol is distilled off, the residue is distilled in vacuum. 30.5 g of unreacted elenol and 76 g of elesaite are obtained, yield 63% of the theoretical one and 83.7% of the amount of reacted elenol.

EXAMPLE 5-19. To estimate the dependence of the yield of elesant on the ratio of reagents and the amount of catalyst, synthesis is carried out analogously to example 1, starting from 25 g of elenol in the presence of an internal standard (tridecan 12.5 g), changing the parameters under study. Without separation of the reaction mass after neutralization, the

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analytical output of elesant as a percentage of the theoretical for the taken elenol on GLC on the chromatograph LHM-8MD-5 with a stainless steel column (3 m X 3 mm), filled with an elastomer SE-30, 5 weight% with a chromaton. % j thermostat temperature, carrier gas rate (helium) 80 cm3 / min. The results are shown in the table.

PRI me R 20. A mixture of 10 g (0.064 mol of elenol, 60 g (1.9 mol) of methanol and 3.5 g of cation exchanger KU-23-15 / 100 in the H form is stirred at 65 ° C5 h, cooled , the catalyst is filtered off, 6 g of elesant is recovered from the filtrate by distillation, the yield is 50% of the theoretical, if taken, and 75% on the reacted elenol.

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92 70 64 67 61 67 58 47 56 65 67 67 66 67 67

20 70 70 70 70 70 73 73 73 72 67 67 67 67 67

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78571038

Claims (2)

Formula inventive 2. Method pop. 1, differing. 1. A method for producing 2-methoxy-2,6-di-yi and that the process is carried out in methyloctanol - by treatment with the me-presence of an acid catalyst, Tilov "alcohol unsaturated compounds in the amount of 0.03-2.5 mol in the presence of acid kata-jna I mol 2,6-dimethylotene - 2-ol-7. 1eatorov, different the fact that, in order to simplify the process-Sources of information, In the examination of water, 2,6-dimes are used as the source of unsaturated waste. tiLoktei-2-ol- 7.№ 1Д14458, cl. C 2C, 1975 (prototype)