CS196167B1 - Method for the continuous production of alpha-ionone and device for making the method - Google Patents

Description

The invention relates to a process for the continuous production of etonone, i. 4- (2-6,6-trimethyl-2-cyclohexenyl) -3-buten-2-one of formula I.

CH ₃ TH

CH-CHCOCH 3

CH, / 1 / sought after perfumery raw materials. The invention also relates to an apparatus for the continuous production of oC-ionone. -Ionone is formed along with its isomer of β-ionone of the cyclic pseudojonone (6,10-dimethyl-3,5,9-undecatrien-2-one) of formula II

CH ₃ C = CHC H 2 CH ₂ ^{CH :: CH "CHCOCH} 3 H ₃ CH _3/11 / effect slightly dilute strong mineral acid, such as 60% sulfuric acid, which is a known reaction, published in the scientific and patent literature. Until now, similarly to the production of # -onone, the cyclization reaction has been carried out in a continuous manner that is demanding in terms of management, consumption of raw materials, energy, and attendance, especially in large scale production / Australian Pat. file no. 231 424 /.

It has now been found that tfC-ionone can be produced preferably by continuous cyclization of pseudojonone with sulfuric acid at a concentration of 60 to 75 wt%, preferably 60 wt%, in the presence of gasoline boiling at 30 to 100 ° C at 20 ° C. to 50 ° C, preferably at 40 ° C, according to the method of the invention, characterized in that the solution of pseu2 of the dojonone in gasoline is contacted continuously with stirring with dilute sulfuric acid at a temperature of 40 ° C, the solution of. in gasoline separated from the aqueous acidic phase is neutralized and treated by steaming and vacuum distillation of the residue to.

The described process is preferably carried out in a device which is also part of the invention and which consists of a cylindrical column provided with a heating mantle, in which a set of agitator discs set in motion by a vibration generator is disposed from a metering pump with a pseudojonone solution a portion of a cylindrical column and a metering pump with a dilute sulfuric acid inlet to the central portion of the cylindrical column, further a drain for the gasoline solution of ob-ion and a overflow line for dilute sulfuric acid.

The device according to the invention is schematically shown in the attached drawing, in which the cylindrical column 1, the set of agitator discs 2 »vibration generator 2» dosing pump 4 for pseudojonone solution, dosing pump 5 for dilute sulfuric acid and an overflow line 7 for effluent dilute sulfuric acid.

In the continuous production (X-Ionone according to the method and apparatus of the invention), pre-heated 60% sulfuric acid is introduced into intensive contact with the pseudojonone gasoline solution in the reaction cylinder column 1. Intensive contact of both phases is possible by a plurality of selective mixing discs. the gasoline solution of the resulting--ion is removed by the outlet v at the top of the column, the dilute sulfuric acid is passed through the overflow line ve at the bottom of the column. The crude residue was purified by distillation under vacuum.

The method of continuous production of IV-ion and the apparatus for carrying out the process according to the invention have a number of advantages over the continuous process: the apparatus is incomparably smaller at the same production capacity, i. whereas it is cheaper and there are considerably less demands on built-up space; the reaction is simple, the control of the continuous process is limited to the simple control of the sulfuric acid temperature in the column. The course of the process is controlled by the rate of dosing of the individual reaction components by the metering pumps, and the reaction mixtures are shifted in and between the individual components of the plant automatically based on the use of gravity principles.

The method and apparatus of the present invention allow for easy start-up and removal of the manufacturing process by starting and stopping the metering pumps and ensuring the consistency of the reaction conditions independent of the undesirable factors resulting from direct operation. With suitable arrangements, especially on a larger scale, dilute sulfuric acid can be recirculated and occasionally replenished in order to compensate for losses due to entrainment with a < X-ionic gasoline solution. Continuous process operation is limited to supervision after setting the basic parameters

Claims (2)

1. Process for the continuous production of (V-ionone, i.e. 4- (2,6,6,6-trimethyl-2-cyclohexenyl) -3-buten-2-one of formula I) CH, CH, CH = CHCOCH, M- ^CH 3 (1) cyclization of pseudojonone, i.e. 6,10-dimethyl-3,5,9-undecatrien-2-one of formula II CH ₃ C = CHCH ₂ CH ₂ CH = CHCH-CHCOCH ₃ CH ₃ (11) by treatment with sulfuric acid at a concentration of 60 to 75% by weight, preferably 60% by weight, in the presence of gasoline boiling at 30 to 100 ° C at 20 to 50 ° C, preferably at 40 ° C, characterized in that the solution above the production device is free from interfering with automatically running reactions, which also represents a significant saving compared to the intermittent process. The details of the process according to the invention are, by way of illustration, given by way of example, without limitation to the conditions set forth therein. Exemplary embodiment Continuous production of ά-jonone on laboratory model of production equipment (see drawing). In a glass cylindrical column 5, 45 mm in internal diameter and 600 mm long, provided with a jacket to which water at 40 ° C, filled with 60% sulfuric acid at the start of the operation, is added, with stirring, The pseudojonone solution in gasoline at a boiling point of 60 to 80 [deg.] C., at a volume ratio of 1: 4, at a rate of 000 ral / h, and a feed pump of 60% sieve acid at a rate of 200 ml / h, are dispensed by the pump. In the reaction cylindrical column 6, the contacting of both reactants at 40 ° C results in cyclization of the pseudojonone to the ε-ionone. From the top of the cylindrical column 6 the gasoline solution of .alpha.-Ion falls and from the bottom a dilute sulfuric acid is removed. The gasoline solution of ¢¢-ion was neutralized with aqueous sodium bicarbonate solution and evaporated at atmospheric pressure. The crude ot-ionone residue is purified by vacuum distillation. Product 8 is obtained with a content of 75% by weight of etonone and about 20% by weight of 3-ionone in a yield of 80% of theory. In accordance with the present invention of pseudojonone in gasoline, it is continually contacted with dilute sulfuric acid at 40 ° C under stirring, the solution of o-4-ionone formed in gasoline separated from the aqueous acidic phase is neutralized. Device for carrying out the method according to claim 1, characterized in that it consists of a cylindrical column (1) provided with a heating jacket, in which a set of agitator discs (2), which is set in motion by the vibration generator (3), comprises a metering pump. (4) with a pseudojonone solution in gasoline feed to the bottom of the cylindrical column (1) and a metering pump (5) with diluted sulfuric acid inlet to the central part of the cylindrical column (1), with an outlet (6) for via a line (7) for dilute sulfuric acid.