Catalyst for selective hydrogenation of 3,7,11-trimethyl-1-dodecyne-3-alcohol

Abstract

The invention discloses a catalyst for selective hydrogenation of 3,7,11-trimethyl-1-dodecyne-3-alcohol to synthesize an important intermediate namely 3,7,11-trimethyl-1-dodecene-3-alcohol of vitamin E. The existing catalysts of the type have low selectivity or low product quality. The catalyst of the invention uses calcium carbonate as a carrier, Pd as an active ingredient and Pb and X as poisoning agents, wherein X refers to metal Mn or / and Zn. During the preparation of the catalyst, a Pd compound is adsorbed to the carrier to perform filtration first, and then perform reduction. The catalyst of the invention has high activity and high selectivity, the quality of a product is improved, and a selected preparation method can greatly reduce the content of the noble metal Pd in the catalyst.

Description

technical field [0001] The invention relates to a catalyst for synthesizing vitamin E intermediates, especially a catalyst for the selective hydrogenation of 3,7,11-trimethyl-1-dodeyn-3-ol to synthesize 3,7,11-tri Catalyst for methyl-1-dodecen-3-ol. Background technique [0002] 3,7,11-Trimethyl-1-dodecen-3-ol is a straight-chain sesquiterpenoid pentadecyl unsaturated tertiary alcohol, and its molecular structure is: [0003] [0004] 3,7,11-Trimethyl-1-dodecen-3-ol is a key intermediate in the synthesis of vitamin E acetate and has important economic value. [0005] So far, there are only sporadic reports on the chemical synthesis of 3,7,11-trimethyl-1-dodecen-3-ol in the open literature. Using poly-2-methyl-5-vinylpyridine as a catalyst and ethanol as a solvent, 3,7,11-trimethyl-1-dodeyn-3-ol is selectively hydrogenated to produce 3,7,11 -Trimethyl-1-dodecen-3-ol was studied. Through the comparison of different additives Co, Fe, Ni, it is found that adding Ni in the...

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Problems solved by technology

Through the comparison of different additives Co, Fe, Ni, it is found that adding Ni in the catalyst can obviously improve the rate of hydrogenation reaction and the reaction rate of 3,7,11-trimethyl-1-dodecen-3-alcohol Selectivity, but the disadvantage of this method is that the yield of 3,7,11-trimethyl-1-dodecen-3-ol is low, about 80%

However, its obvious disadvantage is that it has low selectivity to the catalytic hydrogenation reaction of long-chain alkynols such as 3,7,11-trimethyl-1-dodeyn-3-ol. In order to make up for this defect, usually in the reaction system Add a certain amount of organic compounds such as quinoline

Although this type of organic matter can effectively improve the reaction selectivity, it is easy to change the color of the product and bring peculiar smell, which reduces the product quality, and the subsequent separation of this type of organic matter is also a process of high energy consumption.

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