The preparation method of alpha-terpineol
Technical field
The present invention relates to a kind of preparation method of terpenol of fragrance, relate to a kind of preparation method of alpha-terpineol in particular.
Background technology
Alpha-terpineol is colourless stiff liquid, and the density in the time of 20 ℃ is about 0.931~0.941, refractive index 1.4825-1.4850, boiling point is 214-224 ℃, dissolves in organic solvents such as ethanol, and is water insoluble, have stable Syringa oblata Lindl. fragrance, extensively be present in the multiple essential oil.Terpineol 350 has three kinds of isomer, i.e. α-Shi, β-Shi and γ-Shi Terpineol 350, and the commodity Terpineol 350 is these three kinds of mixture of isomers, wherein based on α-Shi.Content is higher than 90% alpha-terpineol, usually be used as the flotation agent of solvent, sterilant, sterilizing agent, washing agent, clean-out system, blending essence, nonferrous metals ore etc., except as solvent and the fragrance applications, also as organic synthesis intermediate, as dihydroterpineol, acetate pine tar vinegar, Geraniol, pyrethroid, press foline, tobacco flavoring agent etc.1878, Tilden etc. have made Terpineol 350 by the Terpine hydrate dehydration first, the raw material of synthetic Terpineol 350 is firpene (α-Pai Xi, a beta-pinene), firpene adds water and makes Terpine hydrate, then Terpine hydrate being dewatered at a certain temperature makes Terpineol 350, and dewatering agent generally adopts sulfuric acid or phosphoric acid.But by product is many, and raw material consumption is big, the production process complexity, and length consuming time, equipment corrosion is serious, has " three wastes " to pollute.The seventies, Japanese Songyuan City justice are controlled etc., adopt the hydration of chloracetic acid catalysis firpene, opened up the hydration of organic acid catalysis firpene and produced the precedent of Terpineol 350, final product Terpineol 350 yield and selectivity all can match in excellence or beauty with sulfuric acid process, but it is more to consume chloracetic acid, recycling is few, shortcomings such as cost height.In recent years, increasing scientific research personnel works hard on catalyzer, studies the influence of different catalyzer to reaction.Phase transfer catalysis process is arranged, film catalysis method or the like, but these methods all can't resolve the low shortcoming of preparation alpha-terpineol purity.
Summary of the invention
Technical problem to be solved by this invention provides a kind of with 8, and 9-epoxy limonene is a feedstock production purity up to the method for 98% alpha-terpineol.
The technical solution used in the present invention: a kind of preparation method of alpha-terpineol comprises the following steps:
A. under 0 ℃, lithium aluminum hydride is joined in the organic solvent, with 8,9-epoxy limonene is dissolved in the organic solvent, in solutions of lithium aluminium hydride, dropwise add 8,9-epoxy taro alkene solution, under 0~5 ℃, carried out ring-opening reaction 5~10 hours, dropwise dripping frozen water under the whipped state in reaction system emits up to no longer including hydrogen, in reaction system, add the aluminum hydroxide precipitation that concentration 5~20% dilute sulphuric acid solubilizing reactions generate then, separate water layer, ether extraction, the common salt aqueous solution washing, filter, remove ether, obtain crude product, wherein said organic solvent is selected from ether, tetrahydrofuran (THF), N, dinethylformamide or methylene dichloride one of them;
B. crude product separates with silicagel column, makes eluent with the mixed solvent of sherwood oil and ethyl acetate product is carried out drip washing, obtains colourless stiff alpha-terpineol except that after desolvating.
The mixed solvent PetroChina Company Limited. ether of above-mentioned sherwood oil and ethyl acetate: ethyl acetate=3: 1~6: 1.
Beneficial effect of the present invention: the present invention is dissolved in lithium aluminum hydride in the organic solvent at low temperatures, add 8 then, the diethyl ether solution of 9-epoxy taro alkene, carry out the ring-opening reaction of epoxide, obtain the alpha-terpineol crude product, through silicagel column separation, eluent drip washing, to remove and desolvate, the colourless stiff alpha-terpineol purity that obtains at last is greater than 98%.
Description of drawings
Fig. 1 is that GC-9160 type gas chromatograph carries out product quantitative analysis figure.
Embodiment
Below by embodiment the present invention is described in further detail, shown in following reaction formula:
The preparation method of alpha-terpineol comprises the following steps: to comprise the following steps: a kind of preparation method of alpha-terpineol
A. under 0 ℃, lithium aluminum hydride is joined in the organic solvent, with 8,9-epoxy taro alkene is dissolved in the organic solvent, in solutions of lithium aluminium hydride, dropwise add 8,9-epoxy taro alkene solution, under 0~5 ℃, carried out ring-opening reaction 5~10 hours, dropwise dripping frozen water under the whipped state in reaction system emits up to no longer including hydrogen, in reaction system, add the aluminum hydroxide precipitation that concentration 5~20% dilute sulphuric acid solubilizing reactions generate then, separate water layer, ether extraction, the common salt aqueous solution washing, filter, remove ether, obtain crude product, wherein said organic solvent is selected from ether, tetrahydrofuran (THF), N, dinethylformamide or methylene dichloride one of them; B. crude product separates with silicagel column, makes eluent with the mixed solvent of sherwood oil and ethyl acetate product is carried out drip washing, except that after desolvating, obtains colourless stiff alpha-terpineol.Sherwood oil and the ethyl acetate ratio in mixed solvent is a sherwood oil: ethyl acetate=3: 1~6: 1.
Embodiment 1
Take by weighing 0.9865 gram lithium aluminum hydride in the 100mL there-necked flask that the 30mL anhydrous diethyl ether is housed, in the time of 0 ℃, dropwise add 1.0148 grams 8, the anhydrous ether solution of 9-epoxy taro alkene and 10 milliliters, open magnetic stirring apparatus simultaneously, after raw material is added dropwise to complete, reacted at normal temperatures 6.5 hours.The product that reaction is obtained cools off with frozen water, and (drop by drop) drips frozen water very carefully under whipped state, emits up to no longer including hydrogen, and then adds 25 milliliter of 10% sulfuric acid, makes aluminum hydroxide precipitation dissolved.Separate water layer with separating funnel, and, merge ether extracted liquid, use the saturated common salt solution washing again, add Na with ether extraction three times
2SO
4Drying is filtered, and boils off ether, and obtaining product is 0.6316 gram.As shown in Figure 1, through gas Chromatographic Determination Terpineol 350 purity of the present invention greater than 98%.Table 1 has provided the more detailed data of gas Chromatographic Determination.
Table 1
ID |
Retention time (minute) |
Peak height (microvolt) |
Peak area (microvolt * second) |
Content (%) |
1 2 3 4 |
2.3987 3.828 5.156 6.0213 |
3902 684136 4756 6440 |
23579.8 5395604 26895.1 39374.2 |
0.4299 98.362 0.4903 0.7178 |
Embodiment 2
Take by weighing 0.5034 gram lithium aluminum hydride and pour in the 100mL there-necked flask that the 30ml anhydrous tetrahydro furan is housed, cool off magnetic agitation, dropwise add 8 of 0.5011 gram with frozen water, the mixed solution of the anhydrous tetrahydro furan of 9-epoxy limonene and 10ml, normal temperature reacted 6.5 hours down.After reaction finishes, with the frozen water cooling, under agitation drip frozen water, emit up to no longer including hydrogen, add the sulfuric acid of 25ml10% then, aluminum hydroxide precipitation is dissolved.Separate with separating funnel, water layer extracted with diethyl ether three times, combined ether solution is also used the saturated common salt water washing, adds Na
2SO
4Drying is filtered, and boils off ether, and obtaining product is 0.2985 gram.
Above said content only is the basic explanation of the present invention under conceiving, and according to any equivalent transformation that technical scheme of the present invention is done, all should belong to protection scope of the present invention.