RU1768575C - Method of @@@-acetopropyl synthesis - Google Patents

Abstract

SUMMARY OF THE INVENTION: y-acetoxypropyl alcohol of the formula CHC (0) (CH2) ZOH, 80% yield. Reagent 1: y-acetopropyl acetate. Reagent 2: Cs-Siu alcohol or diethylene glycol. Reaction conditions: Acetate: Alcohol molar ratio 1: (1-1.5), 170-205 ° C, titanium tetrabutoxide. 1 tab.

Description

The invention relates to an improved method for producing y-acetopropyl alcohol (5-hydroxypentanone-2), which is used in the manufacture of a polymerization initiator of synthetic rubber-azopentanol-C.

In industry, y-acetopropyl alcohol (APS) is obtained by the simultaneous hydrogenation-hydration of sylvan (a - methylfuran).

The main disadvantage of this method is the low selectivity of the process (about 50%).

There is also a known method for producing y-APS by reacting ethylene oxide with / 3-dicarbonyl compounds, in particular with acetoacetic ester. The main disadvantages of this method for producing y-APS are the relatively low yield of the target product (50-75%), the need to use equimolar amounts of flammable sodium or alkali, a large amount of wastewater, and the low availability of the starting compounds acetylacetones and acetoacetic ether.

The closest solution to the technical problem posed is a method for producing y-APS by hydrolysis of y-acetopropyl acetate (APA) in the presence of KU-2 ion-exchange resin in the H form. The yield of APS is 60-75% based on the initial (loaded) APA. The process is carried out at a temperature of 80-100 ° C with the neutralization of the reaction mass of hydrolysis to pH 3-4 with alkali metal or alkaline earth metal hydroxide.

The disadvantages of the known method for producing y-APS are the relatively low yield of y-APS of 60-75% based on the initial APA, the need for frequent regeneration of the catalyst is ion exchange

About 00

ate

Xi

ate

KU-2 for removal of the side gummy-sulfo derivatives of u-APS that deactivate cation exchanger, as well as the relatively low conversion of APA - not more than 85%, which significantly complicates the isolation and purification of γ-APS and concomitant acetic acid, including from due to the proximity of the boiling points of the γ-ADS AG1XrOb0r and 212 ° C). In this case, the residues of unreacted AflA pa3 / iVrafOt with a 20% aqueous solution of NaOH, which leads to the formation of a large amount of wastewater - about 2.5 t / t of formed y-APS and up to 0.8.t / t APS of non-utilizable sodium acetate CHaCOONa, which is formed upon neutralization of CH3COOH with alkali. Another disadvantage is also the substantial Ergo acid required for the distillation of water and acetic acid from the hydrolyzate synthesis of γ-APS in the known method for the isolation and purification of APS.

The aim of the invention is to increase the yield of the target product and simplify the process technology. The goal is achieved by the method of producing y-acetopropyl alcohol from y-acetopropyl acetate at elevated temperature, and a distinctive feature is that γ-acetopropyl acetate is treated with higher normal fatty alcohols Ce-Xu or diethylene glycol at a molar ratio of γ-acetopropylacetate tagged fatty alcohols Sb-Xu or diethylene glycol equal to 1 (1-1.5), at a temperature of 170-205 ° C and atmospheric pressure in the presence of titanium tetrabutoxide or MOHO-Na-diethylene glycol of the formula NaOCH2CH20CH2CH20H, taken in an amount 2.5-5.5 wt.% Of the initial mixture of reagents with simultaneous purging of the reaction mass with an inert gas with a space velocity of 20-100 hours to produce y-acetopropyl alcohol, its simultaneous decomposition into dihydrosilvan and water, distillation of the dihydrosilvan from the azeotrope reaction zone water, followed by heating to 20-60 ° C and turning into y-acetopropyl alcohol

The process diagram can be described by the following equations

kt

CH3CO CH2) 3OAc + ROH ROAc + CHjCOlCH OH

CH3CO (CH2NJ3OAc-VOHCH2CHzOCH2CH2OK ОНШ2СН2ОСН2СН2ОАСКН3СО (Ш2) 3ОН

kt

sn3co (CkCH s ± OLCH +

The yield of APS is at least 80% at full conversion of APA.

At temperatures above 205 ° C, the reaction mass is ground, and at its

a decrease of less than 170 ° C reduces the yield of APS. A similar result is observed when the molar ratio of APA: HPLC and APA: DEG is less than stoichiometric (1: 1) and when using tetrabutoxidized titanium and mono-Na diethylene glycol catalysts in an amount of less than 2.5 wt.%.

Greater than 1.5-fold # excess of VZhS and DEG and increase in the mass fraction of catalysts more than 5.5 wt.% Does not

to increase the yield of APS and therefore are not practical for economic reasons.

The essence of the invention is the non-obvious reaction-distillation principle of the synthesis of APS, in which the APS resulting from the catalytic transesterification of APA with Sv-Siu or DEG alcohols, at the time of formation, undergoes thermal dihydration to dihydrosilvan with simultaneous distillation of the latter in the form of an azeotrope with water in an inert gas stream from the reaction zone and its subsequent conversion again into APS at 20-60 ° C.

Below 20 ° C, the distillate is not homogenized for a long time (more than 1-2 hours); above 60 ° C, 1 partial entrainment of dihydrosilvan and water can be observed. The process is stepwise, i.e.

without simultaneous distillation of DHA, it leads to a sharp decrease in the yield of APS due to the polymerization of dihydrosilvan at high temperature or its interaction with APS and the formation of a dimer:

sn3ssngsngon + CX O ° SNS

MoHO-Na-diethylene glycol is prepared by dissolving alkali NaOH in diethylene glycol at 100-105 ° С for 1 h. As accompanying APS products, Ca-alcohols alcohols and diethylene glycol monoacetate, which can be used, are formed in quantitative yield. as solvents for varnishes and paints

Example 1. In a three-necked flask equipped with a dropping funnel for feeding the catalyst, a bubbler tube for introducing nitrogen, and also a reflux condenser and a downward condenser cooled with cold water through a jacket, 50 g of APA (0.347 mol) and 68 g of decanol (0, 43 mole). The resulting solution was heated to 190 ° C in an oil bath, while 4.15 g of Ti (H-C4HgO) 4 catalyst were added dropwise while nitrogen sparge was started through the reaction mixture. The dihydrosilvanic water distillation heteroazeotrope is collected in a receiver and trap cooled by dry carbon dioxide.

The dosage of the catalyst is within 4 hours

After adding the entire amount of the catalyst and distilling off the dihydrosilvan with water, the nitrogen supply is stopped, the heating of the reactor is turned off, the cooling of the receiver with distillate is replaced by a bath with warm (40-50 ° C) water. After 20-40 minutes, the distillate is homogenized. Obtain 28.3 g of APS (yield 80%). Conversion APA according to GLC analysis of the bottom residue - 100%.

Example 2. Analogously to example 1, in a three-necked flask equipped with a nitrogen bubbler tube and a reflux condenser, 61.4 g of DEG (0.5 mol) were charged, then 4.0 g of a 40% aqueous solution of NaOH were added thereto, and nitrogen supply is started, maintaining the temperature at 100-105 ° С for 1 h. Free water is removed from the obtained NaOCH2CH20CH2CH20H catalyst solution in DEG by raising its temperature to 170 ° С, after which 55 g of APA are added to the reactor (0.38 mol ) The speed of nitrogen is 9.3 l / h (80), the concentration of mono-Na-diethylene glycol is May 5,%, the temperature of the heat carrier supplied to the jacket of the reflux condenser is 68-70 ° С. After 5 hours, 35.6 g of distillate are obtained, which contains 31.1 g of APS (90% by weight) - 0.31 mol. The yield is 83%. Conversion APA - 100%.

Example 3. By a method analogous to example 1, in a three-necked flask, 45 g (0.31 mol) of APA, 42.7 g of DEG (molar ratio of APA: DEG 1: 1.3) are loaded, then when the temperature reaches 180 ° С 3 g of titanium tetrabutoxide are added dropwise over 5 hours (concentration of 3% of the initial reaction mass). The nitrogen rate is 7.0 l / h (70 h). 30 g of distillate are obtained, which contains 25.6 g of APS (0.25 mol).

Yield 81% of theory.

Example 4. By a method similar to example 2, the fraction is loaded into the flask

alcohols Sa-Syu produced by ALFOL (Ce - 44 wt.%, Syu-55 wt.%) - 82.6 g (0.57 mol). Separately, 5 g of mono-Ma-diethylene glycol was prepared by heating 4.1 g of DEG with 3.8 g

A 40% aqueous NaOH solution, which is then added to the flask to the Cs-Si alcohols. After heating the catalyst solution to 170 ° C and distilling off the water, 60 g of APA - (0.41 mol) are added. Molar ratio

APA: VZHS 1: 1,4. The nitrogen speed is 9 l / h (75), the reaction time is 5.5 hours. 34.3 g of APS (0.34 mol) are obtained — 82% of theory.

When trying to obtain an APS by simultaneously loading all reagents into the reactor without simultaneously distilling the resulting APS in the form of a dihydrosilvan-water azeotrope in an ingas stream, the APS output does not exceed 10-20%.

Examples 5-26. The process is carried out analogously to example 1. The process conditions and the results are shown in the table.

Thus, this method allows to increase the yield of the target product with

60-75% of the prototype to 85% and significantly simplify the process technology by eliminating the stages of neutralization, alkalization, filtration, etc. In this method, a significant reduction in the volume of wastewater occurs.

Claims (1)

The claims The method of producing y-acetopropyl alcohol isu-acetopropyl acetate at elevated temperature, characterized in that, in order to increase the yield of the target product and simplify the process technology, γ-acetopropyl acetate is treated higher normal-structure Ce-Si fatty alcohols or diethylene glycol at a molar ratio of γ-acetopropyl acetate: higher Cs-Syu fatty alcohols or diethylene glycol equal to 1: 1-1.5, at a temperature of 170-205 ° С and atmospheric pressure in the presence of tetrabutoxide titanium or mono-Ma-d and ethylene glycol of the formula NaOCH2CH20CH2CH20H, taken in an amount of 2.5-5.5 wt.% from the initial mixture of reagents while flushing the reaction mass with an inert gas at a space velocity of 20-100 h to obtain acetopropyl alcohol, its simultaneous decomposition into dihydro sylvan and water, distillation from the reaction zone of the azeotrope dihydrosilvan-water, followed by heating to 20-60 ° C and turning into y-acetopropyl alcohol. The alcohols obtained by the organoaluminum method were used. Composition Cj-C | 0: Cj - CC May.2, - JS wt.% The heating temperature of all condensed distillates is 20-60 ° С