A kind of method of separating the purification 1 chloromethyl naphthalene
Technical field
The present invention relates to organic synthesis intermediate, more specifically be meant a kind of method of separating the purification 1 chloromethyl naphthalene.
Background technology
1 chloromethyl naphthalene claims α-chloromethyl naphthalene again, and English name is 1-chloromethylnaphthalene.Crystal, 32 ℃ of fusing points, 135~136 ℃ of boiling points (0.798kPa), specific refractory power 1.6370, density 1.180g/cm3, flash-point>110 ℃ dissolve in ether, benzene, are the tearing property stimulator.
1 chloromethyl naphthalene is a kind of important organic synthesis intermediate, can synthesize products such as α-naphthaldehyde, 1-naphthoic acid, 1-naphthylacetic acid, 1-naphthoyl chloride, 1-naphthalene acetonitrile, 1-naphthalene acetamide, 1-naphthalene methylamine.In 1 chloromethyl naphthalene synthetic, because that the separation of naphthalene is purified is difficult, thereby cause the purity of thick product 1 chloromethyl naphthalene lower, therefore must separate purification to the product that reaction is obtained.
It is that raw material is produced that the synthetic route of present 1 chloromethyl naphthalene all mainly adopts naphthalene.Document " study on the synthesis of α-naphthaldehyde " (Chang Yunheng [J]. fine-chemical intermediate, 2002,32, (2): Chang Yunheng is with naphthalene 27~28), formaldehyde, hydrochloric acid and phase-transfer catalyst extract with hexanaphthene behind the reaction 6h down in 75 ℃, and underpressure distillation obtains 1 chloromethyl naphthalene.Document " phase-transfer catalysis synthetic hydrochloric acid naftifungin " (Xu Baofeng, Zhao Aihua [J]. chemistry world, 2002, (7): Xu Baofeng, Zhao Aihua react naphthalene, Paraformaldehyde 96, Glacial acetic acid, phosphoric acid and concentrated hydrochloric acid to 6h down at 80 ~ 85 ℃ 374~377), use extracted with diethyl ether, underpressure distillation obtains the 1 chloromethyl naphthalene product, yield 68.3%.
The thick product component complexity of 1 chloromethyl naphthalene by naphthalene makes behind chloromethylation contains naphthalene, 2-chloromethyl naphthalene, 1, impurity such as 4-dichloromethyl naphthalene usually.Handle the method that the thick product of 1 chloromethyl naphthalene mainly adopts underpressure distillation at present, but because major impurity is a naphthalene in the thick product, naphthalene component zero pour is 80.2 ℃, and has a stronger sublimability, in distillation, be easy to cause the obstruction of condenser, pipeline, valve and metrical instrument, so actually operating is relatively more difficult.As adopt traditional recrystallization method that thick 1 chloromethyl naphthalene industrial goods are purified, though can obtain the 1 chloromethyl naphthalene of higher degree.But this method will consume a large amount of solvents, yield is low, production cost is high, and the mother liquor after refining can bring problem of environmental pollution, and solvent itself just may be that the impurity of product is originated simultaneously.
Summary of the invention
The object of the present invention is to provide a kind of stationary crystallization to separate the processing method of purification 1 chloromethyl naphthalene, can from mixture, separate the purification 1 chloromethyl naphthalene effectively, reduce production cost, and avoided adopting the problem that causes naphthalene cut crystallization condensation blocking pipeline, equipment in the rectificating method easily.
Technical conceive of the present invention is such:
The fusing point of 1 chloromethyl naphthalene is 32 ℃, the fusing point of naphthalene is 80 ℃, 1, and the fusing point of 4-dichloromethyl naphthalene is 172 ℃, the fusing point of 2-chloromethyl naphthalene is 47 ℃, and the characteristics that can utilize 1 chloromethyl naphthalene and impurity fusing point to differ bigger are thus separated purification with the static distribution crystallization method to 1 chloromethyl naphthalene.
Technical scheme is: will contain naphthalene and 1, the thick product of 1 chloromethyl naphthalene of impurity such as 4-dichloromethyl naphthalene, 2-chloromethyl naphthalene places crystallizer, and heating raises its temperature, collects melt by the differing temps section.Be the 1 chloromethyl naphthalene of purifying at the melt of 30~32 ℃ of collections.
For making cooling evenly, with the extremely fusing of the thick product by heating of 1 chloromethyl naphthalene, progressively cooling makes its slow crystallization then earlier, and cooling rate is too fast, and then crystallization is inhomogeneous; Cooling rate is too slow, then will reduce production efficiency.With the cooling of thick product depth, progressively improve temperature again after the cooling, and collect under 30~32 ℃ of temperature ranges melt.Heat-up rate is too fast, and then purification efficiency reduces; Heat-up rate is too slow, then will reduce production efficiency.
Optimized technical scheme of the present invention comprises the steps:
(1) with the extremely fusing of the thick product by heating of 1 chloromethyl naphthalene;
(2) the thick product of 1 chloromethyl naphthalene after will melting is cooled to 20~30 ℃ with 1-5 ℃/hr speed, is cooled to-10~-20 ℃ again and carries out degree of depth cooling;
(3) the thick product temperature of the cooled 1 chloromethyl naphthalene of the degree of depth is risen to room temperature, be increased to 15~20 ℃ with 5~10 ℃/hr speed;
(4) speed with 0.3~10 ℃/hr continues to improve temperature, is the 1 chloromethyl naphthalene of purification at the melt of 30~32 ℃ of collections.
In the step (1), make its fusing with more than the thick product by heating to 90 of 1 chloromethyl naphthalene ℃.
In the step (2), the degree of depth refrigerative time is 2~3 hours.
In the step (4), preferably the speed with 0.5~5 ℃/hr improves temperature.Collect each component since 20 ℃ to 45 ℃, be the 1 chloromethyl naphthalene of purification at the melt of 30~32 ℃ of collections.Also can under other differing temps sections, collect other impurity.
In the industrial production, can repeat the aforesaid operations process to improve the purity and the yield of product.
Adopt the 1 chloromethyl naphthalene that aforesaid method obtained, its purity can reach more than 99%.Compare with other technology, the present invention is that the isomer by product, product has the principle of different fusing points to purify with impurity, has that cost is low, simple to operate, quality is good, energy consumption is low, the yield advantages of higher.The present invention has avoided adopting naphthalene cut in the rectificating method to cause the problem of crystallization condensation blocking pipeline, equipment easily; Using solvent, is that production process or the finished product have all been avoided the environmental pollution that brought by solvent; Be easy to realize serialization, do not produce waste water.
Embodiment
Product analysis carries out on Agilent 6890 type gas chromatographs, and chromatographic column is the HP-5 capillary chromatographic column.Spectrum peak tie substance comes qualitative with hewlette-packard HP6890 and Britain Micromass GCT type gas chromatography instrument.The chromatographic run condition is: warm 300 ℃ eventually of 60 ℃ of post initial temperature, post, and the post initial temperature is to warm eventually 4 ℃/min of temperature rise rate, post initial temperature hold-time 2min, post be temperature hold-time 35min eventually, 250 ℃ of temperature of vaporization chamber, 320 ℃ of detector temperatures, post flow 1mL/min, splitting ratio 10: 1.
Embodiment 1
With 10 gram purity is that 91.47% 1 chloromethyl naphthalene is a raw material, will melt the back and add in the crystallizer, is warming up to 95 ℃, and it is fully melted in crystallizer.Slowly cooling then, the control cooling rate is at 3 ℃/hr, make it be cooled to 25 ℃, again crystallizer is put into refrigerator-freezer and carried out degree of depth crystallisation by cooling to-15 ℃, and kept 2 hours, after the speed with 10 ℃/hr of then taking out is warmed up to 20 ℃, again heat-up rate is controlled at 1 ℃/hr, collecting melt since 20 ℃ to 45 ℃ by the differing temps section, is 1 chloromethyl naphthalene at the melt of 30~32 ℃ of collections.
Obtain 99.12% 1 chloromethyl naphthalene product 8.1 grams at last, yield 87.77%.
Embodiment 2
With 10 gram purity is that 90.17% 1 chloromethyl naphthalene is a raw material, its fusing back is added in the crystallizer, be warming up to 100 ℃, make its fully fusing in crystallizer, slowly cooling then, the control cooling rate is at 4 ℃/hr, make it be cooled to 20 ℃, to tie the product device again and put into refrigerator-freezer and carry out degree of depth crystallisation by cooling to-10 ℃, and keep 3 hours, the speed of then taking out with 8 ℃/hr heats up; After temperature is brought up to 15 ℃, heat-up rate being controlled at 0.5 ℃/hr, collecting melt since 20 ℃ to 45 ℃ by the differing temps section, is 1 chloromethyl naphthalene at the melt of 30~32 ℃ of collections.
Obtain 99.23% 1 chloromethyl naphthalene product 7.5 grams at last, yield 82.5%.
Embodiment 3
With 10 gram purity is that 89.72% 1 chloromethyl naphthalene is a raw material, its fusing back is added in the crystallizer, be warming up to 110 ℃, make its fully fusing in crystallizer, slowly cooling then, the control cooling rate is at 2 ℃/hr, make it be cooled to 30 ℃, crystallizer is put into refrigerator-freezer again and carried out degree of depth crystallisation by cooling to-20 ℃, and kept 3 hours, the speed of then taking out with 10 ℃/hr heats up; After temperature is brought up to 18 ℃, heat-up rate is controlled at 5 ℃/hr, collect melt since 20 ℃ to 45 ℃ by the differing temps section, collect each component since 20 ℃ to 45 ℃, be 1 chloromethyl naphthalene at the melt of 30~32 ℃ of collections.
Obtain 99.05% 1 chloromethyl naphthalene product 7.3 grams at last, yield 80.59%.
Embodiment 4
With 10 gram purity is that 90.53% 1 chloromethyl naphthalene is a raw material, its fusing back is added in the crystallizer, be warming up to 90 ℃, make its fully fusing in crystallizer, slowly cooling then, the control cooling rate is at 1 ℃/hr, make it be cooled to 27 ℃, crystallizer is put into refrigerator-freezer again and carried out degree of depth crystallisation by cooling to-18 ℃, and kept 3 hours, the speed of then taking out with 5 ℃/hr heats up, after temperature is brought up to 15 ℃, heat-up rate being controlled at 2 ℃/hr, collecting melt since 20 ℃ to 45 ℃ by the differing temps section, is 1 chloromethyl naphthalene at the melt of 30~32 ℃ of collections.
Obtain 99.18% 1 chloromethyl naphthalene product gram 7.9 grams at last, yield 86.55%.