Synthesis of Prenyl Alcohol by Isomerization of Aqueous Methyl Butenol

Abstract

The invention belongs to the field of chemical engineering and particularly relates to isomerization synthesis of 3-methyl-2-buten-1-ol using methyl butenol in a water-containing condition. In the invention, the methyl butenol is adopted as a raw material for isomerization synthesis of 3-methyl-2-buten-1-ol; in the reaction materials, the water content is 0.5-6.5%; the catalyst is vanadium oxide or vanadium-containing metal salt; the catalyst concentration is 0.1-5.0%, the reaction temperature is 120-190 DEG C, and the reaction time is 20-180min; the purity of the obtained 3-methyl-2-buten-1-ol product is higher than or equal to 98%; and the 3-methyl-2-buten-1-ol selectivity in the reaction process can be controlled at 95% or above. The invention has the following advantages: the adopted catalyst does not need to be prepared in advance and is relatively cheap; the raw material methyl butenol can be adopted for isomerization synthesis of 3-methyl-2-buten-1-ol in a water-containing condition; and the reaction activity and selectivity are relatively high.

Description

technical field [0001] The invention belongs to the field of chemical engineering, in particular to the isomerization of water-containing methyl butenol to synthesize isopentenol. Background technique [0002] Isopentenol is an important spice, pharmaceutical and pesticide intermediate, mainly used to produce citral, isophytol, DV permethrin, etc., and also used to synthesize the third generation cement water reducer, polycarboxylate water reducer Raw material TPEG. According to the different sources of raw materials, there are mainly three routes for the formation of prenyl alcohol: the condensation of isobutylene and formaldehyde, the method of acetylene acetone and the hydration of isoprene. [0003] Using acetylene acetone as a raw material to obtain methyl butynol through alkynylation, and then half-hydrogenating to generate methyl butenol, and then isomerizing to obtain isopentenol. In this process route, the alkynylated product methyl butynol and water form an azeot...

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Problems solved by technology

However, this reaction system introduces more other components, which increases the subsequent separation process and brings about the problem of solvent loss.

In addition, from the results reported by the patent, the reaction rate is very slow, and the conversion rate of reaction 4-15h is only 22%

When Rajender Reddy Leleti et al. used methanesulfonic acid as a catalyst, the reaction rate was slow and the selectivity was not high. In THF / H 2 Reaction in O solvent for 12h, the selectivity of the product is only 74%

[0007] It can be seen from the above that the problem of the isomerization of methyl butenol to generate isopentenol is that the use of pre-prepared vanadate catalysts requires deep water removal of raw materials and the selectivity is not high. Not high and selectivity is low, and the use of rhenium-based catalysts with higher reactivity is very expensive

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