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Method of selective cyclization of myrac aldehyde catalyzed by supported tungsten carbide for preparation of cyclic myrac aldehydes

A tungsten carbide catalyzed and supported technology is applied in the preparation of carbon-based compounds, chemical instruments and methods, catalysts for physical/chemical processes, etc. Mild conditions, low cost, high activity and selectivity

Active Publication Date: 2019-04-19
DALIAN INST OF CHEM PHYSICS CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The traditional production process of citrus cyanal uses protonic acids such as sulfuric acid, phosphoric acid, p-toluenesulfonic acid, Amberlite H + etc. are catalysts (Bull.Chem.Soc.Chim.Fr.1959,601-606; EP 0743297, priority 16.5.1995 toGivaudan[Chem.Abstr.126,103856h]), there are large amounts of catalyst, relatively harsh reaction conditions, and the product Disadvantages such as not easy to separate, serious environmental pollution and non-reusable

Method used

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  • Method of selective cyclization of myrac aldehyde catalyzed by supported tungsten carbide for preparation of cyclic myrac aldehydes
  • Method of selective cyclization of myrac aldehyde catalyzed by supported tungsten carbide for preparation of cyclic myrac aldehydes
  • Method of selective cyclization of myrac aldehyde catalyzed by supported tungsten carbide for preparation of cyclic myrac aldehydes

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] W 2 C / AC(W 2 C is tungsten carbide, and AC is activated carbon) The specific preparation method is as follows:

[0018] Dissolve ammonium metatungstate in water so that the mass concentration of ammonium metatungstate is 0.4g / ml. Then, the solution was impregnated with activated carbon support (AC) by the method of equal volume impregnation. After oven drying at 120 °C for 12 h, the catalyst precursor was placed in H 2 A temperature-programmed carbothermal reaction was carried out in the atmosphere. The specific reaction process was as follows: 1.0 g of precursor was heated from room temperature to 400 °C in a quartz reaction tube for 1 h, then raised to 700 °C at 1 °C / min and kept for 1 h for carbonization. The hydrogen flow rate was 60ml / min. A tungsten carbide loading of 30wt% W 2 C / AC catalyst.

[0019] Other conditions remain the same, only change the concentration of ammonium metatungstate in the impregnation solution to obtain catalysts with different loadi...

Embodiment 2

[0021] Tungsten carbide is supported on alumina, silica, titania, zirconia, titania, silica-alumina molecular sieve, and phosphorus-aluminum molecular sieve to prepare supported tungsten carbide catalyst WxC / B (WxC is tungsten carbide, 1≤x≤2; B It is a porous carrier, which is activated carbon, alumina, silica, zirconia, titania, silica-alumina molecular sieve, phosphorus-aluminum molecular sieve). : The preparation process is similar to Example 1, except that the carrier uses alumina, silica, zirconia, titania, silicon-aluminum molecular sieve, phosphorus-aluminum molecular sieve instead of activated carbon, and at the same time, the carbonization gas is changed from hydrogen to CH 4 / H 2 (Volume ratio 1:4), the loading amount of tungsten carbide in the catalyst is 30wt%, thus obtained six kinds of catalysts with tungsten carbide loaded on alumina, silica, zirconia, titania, silica-alumina molecular sieve, and phosphorus-aluminum molecular sieve .

Embodiment 3-18

[0023] W 2 C / AC catalyzed the selective cyclization of p-citrus aldehyde to prepare citrus aldehyde: 0.5 g of citrus aldehyde was mixed with a certain mass of W in the reaction kettle 2 The C / AC catalysts were dissolved in 50ml of toluene, and replaced with nitrogen five times to make the initial pressure of nitrogen 0.1MPa-20MPa, the temperature was raised to 50-200°C, and the stirring reaction was carried out at a speed of 1000 rpm for 0.5-24h. After the reaction was completed, the temperature was lowered to room temperature, and the supernatant was filtered and then sampled for analysis. Qualitative analysis of the product was carried out by GC-MS technology and standard sample control, and quantitative analysis was realized by gas chromatography internal standard method. The reaction results are shown in Table 1.

[0024] Table 1 W under different conditions 2 C / AC catalyzed the cyclization reaction of 4-(4-methyl-3-pentenyl)-3-cyclohexenal (p-citral) to generate cycloc...

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Abstract

The invention relates to a cyclization reaction of myrac aldehyde catalyzed by tungsten carbide, specifically to a method of selective cyclization of myrac aldehyde catalyzed by supported tungsten carbide for preparation of cyclic myrac aldehydes. According to the method, para- / meta- myrac aldehyde is used as a raw material to undergo a highly selective reaction in an organic solvent at 50-150 DEGC to generate cyclic myrac aldehydes 1,2,3,4,5,6,7,8-octahydro-,8,8-dimethyl-2-naphthaldehyde and 1,2,3,4,5,6,7,8-octahydro-5,5-dimethyl-2-naphthaldehyde. The conversion rate of the substrate reachesup to 100%, and yield of the target product reaches up to 99%. Compared with the conventional catalytic route, the supported non-noble metal tungsten carbide is used as a catalyst without the use ofinorganic acid or alkali in the invention, thus avoiding generation of a large amount of acid liquor by traditional catalysis. The invention has the following characteristics: the reaction condition is mild; the catalyst is cheap and recyclable and has high activity and selectivity; and the reaction process is environmentally-friendly.

Description

technical field [0001] The invention relates to the efficient catalytic reaction of citrus aldehydes to prepare citrus aldehydes, in particular to a method for preparing citrus aldehydes through efficient conversion of citrus aldehydes by using loaded non-noble metal tungsten carbide instead of traditional liquid acid catalysts. Background technique [0002] Citrus green aldehyde, also known as Merlot, includes two isomers (Formula 1), and the full names are 1, 2, 3, 4, 5, 6, 7, 8-octahydro-, 8, 8-dimethyl Dimethyl-2-naphthaldehyde and 1,2,3,4,5,6,7,8-octahydro-5,5-dimethyl-2-naphthaldehyde. These two isomers have a pleasant woody fragrance and a complex herbal fragrance respectively. They are necessary intermediates for the synthesis of various valuable spices and are widely used in fields such as perfumes and cosmetics (see literature: a) Ohloff, G. Riechstoffe Aromen 1957, 38-40. b) Ohloff, G. DE 1057108, 1957, Dragoco Spezialfabrikkonz. Riech-und Aromastoffe Gerberding ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C45/67C07C47/347B01J27/22B01J29/83B01J29/06
CPCB01J27/22B01J29/06B01J29/83B01J2229/18C07C45/67C07C47/347Y02P20/584
Inventor 李昌志代弢季建伟王爱琴张涛
Owner DALIAN INST OF CHEM PHYSICS CHINESE ACAD OF SCI
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