The synthetic method of watermelon ketone
Technical field
The present invention relates to chemical technology field, be specifically related to a kind of synthetic method of watermelon ketone.
Background technology
Watermelon ketone is referred to as Calone/Watermelon ketone abroad, chemistry 7-methyl-3 by name, 4-dihydro-2H-1,5-benzo dioxa Zhuo-3-ketone.
Along with the development of fragrance industry, watermelon ketone is widely used, because watermelon ketone itself, is a kind of new principle to the preparation of perfume, so become domestic and international blending expert's new selection.China is to the main dependence on import of the demand of watermelon ketone.Synthetic method about watermelon ketone mainly contains following several.For example:
U.S.'s report is condensed into the intermediate of dicarboxylic ester class with 4-methyl pyrocatechol and methyl bromoacetate; then under the effect of highly basic; by the Dieckmann condensation, obtain the compound of 2-methoxycarbonyl base, and then hydrolysis decarboxylation obtains watermelon ketone in alcohol hydrochloric acid.
The scholar that Canadianizes is that starting raw material prepares watermelon ketone in order to 4-methyl pyrocatechol and chloromethyl cyanide.
The scholar that Italianizes uses 4-methyl pyrocatechol and l, and the 3-dichlorohydrine is condensed into intermediate benzocyclohepta alkanol, and then oxidation obtains watermelon ketone, but yield 4%.
Also have take 4-methyl pyrocatechol and Dichloro acetone as raw material, the condensation of 4-methyl pyrocatechol by becoming ring, is reset and also can be obtained watermelon ketone, although reactions steps is simple, but the one-step synthesis watermelon ketone, but yield also can only reach 50%.
To sum up, the disclosed method of America ﹠ Canada all requires to use highly basic NaH as reagent, severe reaction conditions, and reaction yield is low, is not suitable for suitability for industrialized production; The disclosed method yield of Italy is too low, does not have utility value; Take 4-methyl pyrocatechol and Dichloro acetone as raw material, by becoming ring, reset and obtain watermelon ketone, although the method can neither very high (can only reach 50%) for the production of, yield.
The patent application that proposes before the applicant, application number are 200810244583.7 to disclose a kind of synthetic method of watermelon ketone, and this synthetic method adopts one kettle way to carry out, and maximum defective is that yield is very low (being lower than 50%) also.
Summary of the invention
The technical problem to be solved in the present invention provides a kind of synthetic method of watermelon ketone, and this synthesising method reacting condition is easily controlled, and is simple to operate, and yield is high, and production cost is low, and reaction safety, environmental protection can realize suitability for industrialized production.
Technical scheme of the present invention is:
The synthetic method of watermelon ketone comprises the following steps:
(1) under nitrogen protection, adds mass concentration in the reactor and be
40~50The ﹪ sodium carbonate solution, nitrogen protection adds the 4-methyl pyrocatechol, is warming up to 60~80 ℃ of reactions 1~2 hour, then adds toluene in reactor, and heating evaporation is taken the moisture in the material out of under normal pressure;
(2) in the material of step (1), add organic amine, iodate amine, then drip 1,3-DCA and alcohol or 1,3-DCA and butanone mixing solutions at 60~80 ℃, drip off rear insulation back flow reaction 3-5 hour; Cooling, suction filtration gets crude product, and described crude product is sloughed alcohol or butanone, toluene under condition of negative pressure;
(3) slough crude product behind alcohol or butanone, the toluene to neutral with metabisulfite solution washing step (2), then underpressure distillation, fraction gets the watermelon ketone of white crystalline solid with acetone and normal hexane mixed solvent recrystallization.
4-methyl pyrocatechol and 1, the mol ratio of 3-Dichloro acetone is 1:0.9~1.05, the mol ratio of yellow soda ash and 4-methyl pyrocatechol is 1:0.4~0.5, and the mol ratio of ammonium iodide and 4-methyl pyrocatechol is 1:10.0~7.5, and organic amine and ammonium iodide mol ratio are 1:0.8~2.
The volume ratio of acetone and normal hexane is 1:1~1.5 in the mixed solvent, and the volume ratio of described mixed solvent and fraction is 1~3:1.
1,3-DCA and pure mass ratio are: 1:4~10,1,3-DCA and butanone mixing quality ratio are: 1:4~7.Described alcohol is methyl alcohol or ethanol.
Describedly add toluene in step (1) material, sodium carbonate solution with the volume of toluene ratio is: 1:1.5~3.
Described organic amine is diethylamine or triethylamine.
Chemical equation is as follows:
The present invention compared with prior art has following obvious advantage:
The condition of the present invention's reaction is to react under lower temperature, and solvent is many, and temperature is controlled simply in the reaction process, and the reaction water of its recovery can reclaim and continue to use.Can find out that from equation adopt the present invention, the material selectivity ratios is higher in its reaction process, by product is few, has reduced the reaction loss, the then corresponding minimizing of production cost.
Embodiment
Below in conjunction with concrete example, the present invention is described in further detail.Should be understood that these embodiment just in order to demonstrate the invention, but not limit the scope of the invention by any way.
Embodiment 1
Adding mass concentration in the 2000ml four-hole round-bottomed flask of thermometer, reflux condensing tube, water trap, agitator is housed is 50% sodium carbonate solution 440g, under the nitrogen protection, add the 124g4-methyl pyrocatechol, be warming up to 60~80 ℃ of reactions 1~2 hour, adding 800ml toluene heating evaporation is taken away the moisture in the material;
When steaming without moisture to the material, material is cooled to 60 ℃, adds successively 5g triethylamine, 14g ammonium iodide, slowly drips 1,3-DCA and the 300ml alcohol mixed solution of 130g, drips off follow-up continuation of insurance temperature back flow reaction 3-5 hour; Reaction process sampling GC analyzes, when 1,3-DCA less than 0.01% stopped reaction, cooling, suction filtration gets crude product, again with crude product under condition of negative pressure, slough ethanol, toluene, obtain precipitation crude product 180g, watermelon ketone content is 95% in the precipitation crude product;
Be washed till neutrality with metabisulfite solution, watermelon ketone fraction 153 grams are collected in underpressure distillation, and cut gets white crystals watermelon ketone 145 grams with acetone and the normal hexane mixed solvent secondary crystal of 200ml 1:1, and content 98.5%, yield are 80.2%.
Embodiment 2
Adding mass concentration in the 2000ml four-hole round-bottomed flask of thermometer, reflux condensing tube, water trap, agitator is housed is 50% sodium carbonate solution 460g, nitrogen protection, add the 124g4-methyl pyrocatechol, 60~80 ℃ of reactions of temperature control 1~2 hour, adding 800ml toluene heating evaporation is taken away the moisture in the material;
When steaming without moisture to the material, material is cooled to 60 ℃, adds successively .8g diethylamine, 15g ammonium iodide, slowly drips the 1,3-DCA of 120g and the mixing solutions of 300ml butanone, drips off follow-up continuation of insurance temperature back flow reaction 3-5 hour; Reaction process sampling GC analyzes, when 1,3-DCA less than 0.01% stopped reaction, cooling, suction filtration gets crude product, again with crude product under condition of negative pressure, slough butanone, toluene, receive precipitation crude product 175g, content is 96%;
Be washed till neutrality with metabisulfite solution, watermelon ketone fraction 150 grams are collected in underpressure distillation, and cut gets white crystals watermelon ketone 142 grams with acetone and the normal hexane mixed solvent secondary crystal of 200ml 1:1.3, and content 99.2%, yield are 83.3%.
Embodiment 3
Adding mass concentration in the 2000ml four-hole round-bottomed flask of thermometer, reflux condensing tube, water trap, agitator is housed is 50% sodium carbonate solution 480g, nitrogen protection, add the 124g4-methyl pyrocatechol, 60~80 ℃ of reactions of temperature control 1~2 hour, adding 800ml toluene heating evaporation is taken away the moisture in the material;
When steaming without moisture to the material, material is cooled to 60 ℃, adds successively 10g triethylamine, 17g ammonium iodide, slowly drips the 1,3-DCA of 126g and the mixing solutions of 500ml butanone, drips off follow-up continuation of insurance temperature back flow reaction 3-5 hour; Reaction process sampling GC analyzes, when 1,3-DCA less than 0.01% stopped reaction, cooling, suction filtration gets crude product, again with crude product under condition of negative pressure, slough butanone, toluene, receive precipitation crude product 183g, content is 95.5%; Be washed till neutrality with metabisulfite solution, watermelon ketone fraction 155 grams are collected in underpressure distillation, and cut gets white crystals watermelon ketone 142 grams with acetone and the normal hexane mixed solvent secondary crystal of 200ml 1:1.5, and content 99.3%, yield are 79.2%.