A kind of preparation method of hexanolactam
Technical field
The present invention relates to a kind of preparation method of-hexanolactam, particularly finger ring hexanone oxime and nicotinic acid or sulfuric acid are being the method for preparing hexanolactam under the inert solvent existence condition to nicotinic acid or sulfuric acid.
Background technology
Cyclohexanone-oxime is to generate hexanolactam according to Beckmann rearrangement.Industrial, rearrangement reaction is the homogeneous reaction of carrying out with strong acid.Normally rearrangement reaction takes place with the nicotinic acid that contains any sulphur trioxide concentration down at 70 ℃~130 ℃ in cyclohexanone-oxime, and the reaction mixture that contains hexanolactam then neutralizes with ammoniacal liquor, and hexanolactam is separated from ammonium sulfate solution again.In the above-mentioned technology, in the preparation hexanolactam, produce a large amount of sulphur ammoniums.If reaction is to utilize the nicotinic acid single-stage to reset, 1 ton of hexanolactam approximately produces 1.7 tons~1.9 tons sulphur ammoniums.This technology is owing to consume the sulfuric acid and the ammoniacal liquor of high value, the sulphur ammonium of by-product low value, and have problem such as equipment corrosion, therefore for a long time since, people are seeking the no by-product or the novel method of the production hexanolactam of by-product sulphur ammonium less always.
There also have some patents to propose condition before this to be gentle or do not have a liquid phase rearrangement method of by-product sulphur ammonium, there is the bright people of grade in Japanese kokai publication hei 4-342551, to study employing N as SUMITOMO CHEMICAL Co., Ltd. spring, at least a phosphide in the middle of the disubstituted alkylamide of N-and chloro thiophosphoric acid diester, hydroxyl phosphorus trichloride and the phosphorus pentachloride is made catalyzer, carries out the technology that oxime is converted into corresponding amides in the presence of solvent.Temperature of reaction is usually at 20 ℃~150 ℃.But the hexanolactam yield is less than 70%wt, and reaction system is formed complicated.
The middle forest of Ube is just being recorded and studying the technology of using phosphoric acid or condensed phosphoric acid based compound to make the rearrangement reaction catalyzer of alicyclic ketoxime in Japanese kokai publication sho 62-149665 in addition.This reaction generally is to carry out in solvent, and the rearrangement reaction temperature is 80 ℃~150 ℃; Reaction times 20min~300min; The consumption of phosphoric acid or condensed phosphoric acid systemization platform thing is that every mole of oxime uses 1.1mol~3.0mol (to be converted into P
2O
5).Still need after the reaction with the ammonia neutralization, hexanolactam reclaims after with solvent extraction; Ammonium phosphate decomposes under 200 ℃~800 ℃ temperature, and the ammonia of recyclable 60%wt~95%wt (molar yield that is equivalent in the ammonium phosphate salt full ammonia amount), the main drawback of this patent are that ammonium phosphate decomposes that to need high temperature, energy consumption height, advantage be no ammonium salt as by-product by.
The Peter Horn of Germany BASF AG, Otto-Alfred Grosskinsky etc. were at US4 in 1979,257, in 950 patents also to cyclohexanone-oxime by being dissolved in the solvent to nicotinic acid inertia and water insoluble and nicotinic acid, still utilize nicotinic acid to carry out Beckmann rearrangement and generate hexanolactam and carried out research as catalyzer.Its principal feature is that cyclohexanone-oxime is dissolved in cycloalkane (as the mixture of pentamethylene, hexanaphthene, suberane or these materials) solvent, and with the nicotinic acid reaction, rearrangement reaction heat is returned by solvent evaporation and phlegma and removed under intense mixing; Reactant is divided into two-phase, and the upper strata is a solvent phase, can be recycled by washing regeneration; Lower floor be hexanolactam with nicotinic acid mutually, by separating in the ammoniacal liquor with hexanolactam, and by method refined caprolactam such as extractions.The advantage of this patent: the one, can not cause local superheating during reaction, reaction heat energy is in time removed; The 2nd, technology is simple, is easy to industrialization; The 3rd, the hexanolactam impurity of this explained hereafter is reset technology than simple nicotinic acid and is lacked; The 4th, hexanolactam yield height can reach more than 98.5%.Shortcoming is that by-product sulphur ammonium does not reduce.
Above technology because of solvent or catalyst recovery difficulty, product yield is low or by-product sulphur ammonium does not reduce and do not realize industrialization.
Summary of the invention
The object of the present invention is to provide a kind of preparation method of hexanolactam, particularly finger ring hexanone oxime and nicotinic acid or anhydrous slufuric acid are being the method for preparing hexanolactam under the inert solvent existence condition to nicotinic acid or sulfuric acid.
Technical process of the present invention is made up of circulation line 1, recycle pump 2, reactor 3, condenser 5 and separator 6.Reaction mixture or nicotinic acid are by recycle pump 2 circulations, nicotinic acid or anhydrous slufuric acid are to add by pipeline 6, cyclohexanone-oxime is to add by pipeline 7, mix fully at reactor with circulating mixture, rearrangement reaction heat shifts out by condenser 4, and in separator 5, reaction mixture is divided into solvent phase and contains own nicotinic acid mutually, the solvent that contains unnecessary nicotinic acid returns use by pipeline 8, and the hexanolactam that is dissolved in the nicotinic acid enters neutralization and caprolactam refining operation by pipeline 9.
(1) solvent that uses in the present invention is that nicotinic acid or sulfuric acid are inert halohydrocarbon, ester class, ketone equal solvent.
(2) using halogenated hydrocarbon solvent in the present invention is trichloromethane, trieline, 1,2-ethylene dichloride, 1 etc.; Esters solvent is butylacetate, tributyl phosphate etc.; Mibk etc.
(3)) catalyzer that uses in the present invention as nicotinic acid or anhydrous slufuric acid wherein nicotinic acid be meant the sulfuric acid that contains free sulphur trioxide.
(4)) solvent that contains unnecessary nicotinic acid in the present invention returns use.
(5)) in the present invention only need be during ordinary production with anhydrous slufuric acid and without nicotinic acid.
(6) solvent usage quantity in the present invention is 5%wt~50%wt to keep cyclohexanone-oxime concentration, is generally 10%wt~30%wt.
(7)) temperature of reaction in the present invention is 50 ℃~120 ℃, is preferably 90 ℃~110 ℃.
(8)) reaction times in the present invention is 0.25hr~1.0hr, is preferably 0.3hr~0.7hr.
Positively effect of the present invention is: the solvent that contains unnecessary nicotinic acid can return use, the raw material cyclohexanone-oxime and the vitriolic mol ratio of rearrangement reaction can be reduced to theoretical value 1: 1, and need only to use anhydrous slufuric acid during ordinary production except that just beginning to feed intake in producing with the nicotinic acid.Rearrangement reaction in the present invention can be used halogenated hydrocarbon solvent, can omit traditional hexanolactam solvent extraction.Compare with traditional technology, by-product sulphur ammonium reduces 20~40%.Reaction conditions gentleness of the present invention can be avoided local superheating simultaneously, reduces side reaction, and has the cyclohexanone-oxime conversion fully, hexanolactam selectivity advantages of higher.
Description of drawings
Fig. 1 is a schematic flow sheet of the present invention.
Embodiment
The present invention will be further described below by example.
Example 1: with the dissolving of 400ml mibks, at first the hexanolactam nicotinic acid solution (sulfuric acid and hexanolactam mole ratio are 1.20) that contains that 50g is fetched from full scale plant is poured one into and is used N with 113 gram cyclohexanone-oximes
2Be heated to 105 ℃ and keep this temperature at the bottom of the 1000ml garden of band stirring and refluxing of protection in the flask; in 0.5hr, drip above-mentioned cyclohexanone-oxime solution for preparing and 98g nicotinic acid simultaneously; standing demix behind the continuation reaction 0.5hr; lower floor's material with in the ammoniacal liquor and after get the organic layer chromatographically again; cyclohexanone-oxime transformation efficiency 100%; hexanolactam selectivity 98.5%, lower floor's material sulfuric acid and hexanolactam mole ratio are 0.92.
Example 2:, with the dissolving of 400ml butylacetates, at first the hexanolactam nicotinic acid solution (sulfuric acid and hexanolactam mole ratio are 1.20) that contains that 50g is fetched from full scale plant is poured one into and is used N with 113 gram cyclohexanone-oximes
2Be heated to 105 ℃ and keep this temperature at the bottom of the 1000ml garden of band stirring and refluxing of protection in the flask; in 0.5hr, drip above-mentioned cyclohexanone-oxime solution for preparing and 98g nicotinic acid simultaneously; standing demix behind the continuation reaction 0.5hr; lower floor's material with in the ammoniacal liquor and after get the organic layer chromatographically again; cyclohexanone-oxime transformation efficiency 100%; hexanolactam selectivity 98.5%, lower floor's material sulfuric acid and hexanolactam mole ratio are 0.80.
Example 3: with 113 gram cyclohexanone-oxime 400ml1, the 2-ethylene dichloride dissolves, and at first the hexanolactam nicotinic acid solution (sulfuric acid and hexanolactam mole ratio are 1.20) that contains that 50g is fetched from full scale plant is poured one into and used N
2Be heated to 105 ℃ and keep this temperature at the bottom of the 1000ml garden of band stirring and refluxing of protection in the flask; in 0.5hr, drip above-mentioned cyclohexanone-oxime solution for preparing and 98g nicotinic acid simultaneously; standing demix behind the continuation reaction 0.5hr; lower floor's material with in the ammoniacal liquor and after get the organic layer chromatographically again; cyclohexanone-oxime transformation efficiency 100%; hexanolactam selectivity 98.6%, lower floor's material sulfuric acid and hexanolactam mole ratio are 0.90.