Method for producing acetylene alcohol compounds using continuous process

Abstract: There is disclosed a method for producing acetylene alcohol compounds in a continuous process, which are produced via ethynylation in which ketones containing a group -CH 2 COCH 2 -, are condensed with acetylenes at a temperature of about 20 to 50 °C under a pressure of about 10 to 30 kg/cm 2 in the presence of a quaternary ammonium hydroxide anion exchange resin having strong basicity in an aprotic solvent by feeding a reactant mixture at an LHSV range of 0.1 to 5.0 and the reactant mixture comprises the acetylene, the ketone and the solvent at a molar ratio of 1.0:0.2-3.0:1.0-4.0.

Description: BACKGROUND OF THE INVENTION Field of the invention The present invention relates to a method for producing acetylene alcohol compounds in a continuous type process using strong basic, heterogeneous anion exchange resins. More specially, the present invention relates to an ethynylation in which acetylene and ketone compounds are condensed in a continuous process in an aprotic solvent in the presence of quaternary ammonium hydroxide anion exchange resins, as represented by the following reaction formula I, thereby producing commercially useful acetylene alcohol compounds at high yields with environmental favorableness: wherein R 1 and R 2 , which may be the same or different, each is a hydrogen atom, a linear or branched, saturated or unsaturated alkyl containing 1 to 16 carbon atoms, or a linear or branched, saturated or unsaturated phenyl containing 1 to 16 carbon atoms. Description of the Prior Art Thus far, acetylene alcohol compounds have been prepared through the condensation of ketone and acetylene by the method which was developed by Favorskii. According to Favorskii's method, acetylene is converted into acetylide in the presence of a metal salt capable of deprotonation in liquid ammonia or another suitable solvent, followed by condensing the acetylide with appropriate ketones to provide desired acetylene alcohol compounds. Besides liquid ammonia, ethers are usually used as the solvents. As for the catalysts carrying out the condensation reaction, they comprise metal salts of strong base, e.g, alkaline metal hydroxides, and particularly, potassium hydroxide is usually used. This method is, however, found to be disadvantageous in several points. First, excess amounts of alkaline metal hydroxide should be used. That is, it is needed to be used with stoichiometric to excess amounts of metal hydroxides compound to ketones used, and this results in a considerable inefficiency in economical and environmental aspects. One of the requirements which a good reaction must meet, is that undesirable by-products be produced as little as possible. However, the use of excess amounts of alkaline metal hydroxides induces production of the by-products, resulting in a decrease in the production yield of the ultimate objects, acetylene alcohol compounds. Moreover, because the above acetylene alcohol production reaction is reversible, the conversion rate of ketones and the production yield of acetylene alcohols could be decreased during the separation and purification of the product at higher temperature with the presence of a catalyst. On the basis of the experiment data established thus far, liquid ammonia is used as the most efficient solvent for the reaction in light of the production yield of the object acetylene alcohol compounds and the conversion rate of ketones. To be used as a solvent, ammonia should be liquified, which requires a very low temperature and thus, a corresponding energy. In addition, the low temperature imposes a stiff burden on the recovery of the product. Moreover, liquid ammonia is unfavorable to the environment. SUMMARY OF THE INVENTION Thorough and intensive research repeated by the present inventors aiming to develop a method for producing acetylene alcohol compounds at high yields, resulted in the finding that the ethynylation of ketones with acetylenes in an aprotic solvent in the presence of a quaternary ammonium hydroxide anion exchange resin having strong basicity under a mild condition can bring about a great improvement in the conversion rate of ketones and the selectivity for acetylene alcohol compounds and the regeneration of the anion exchange resin allows the acetylene alcohol compounds to be produced continuously. Therefore, it is an object of the present invention to provide a method for producing acetylene alcohol compounds in the mild condition in which no liquid ammonia and a minimal amount of alkali metal hydroxide are used, thereby greatly improving the production yield with environmental favorableness. It is another object of the present invention to provide a method for producing acetylene alcohol compounds, which is applicable to commercial end. In accordance with the present invention, there is provided a method for producing an acetylene alcohol compound in a continuous process comprising the steps of: (i) saturating an acetylene gas in an aprotic solvent selected from the group consisting of dimethylformamide, dimethyl sulfoxide and N-methylpyrrolidone in a first reactor in the absence of liquid ammonia and alkali metal hydroxide; (ii) mixing the saturated acetylene solution with a ketone containing a CH 2 COCH 2 to form a reactant mixture of said acetylene, ketone and solvent in a molar ratio of 1.0:0.2-3.0:1.0-4.0; (iii) feeding the reactant mixture into one of a second and third reactor, said second and third reactors containing a strongly basic quaternary ammonium hydroxide anion exchange resin, at a liquid hourly space velocity in the range of 0.1 to 5.0; and (iv) reacting the reactant mixture in the presence of said resin at a temperature of about 20 to 50°C. under a pressure of about 10 to 30 kg/cm 2 ; said second and third reactors being alternately operated to permit the regeneration of said resin in one reactor while said other reactor is being operated. BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects and aspects of the invention will become apparent from the following description of embodiments with reference to the accompanying drawings in which: Fig. 1 is a schematic diagram showing an apparatus in which acetylene alcohol compounds can be produced in a continuous process, according to the present invention; Fig. 2 is a graph showing the conversion rates of acetone plotted against times in accordance with Example VII; Fig. 3 is a graph showing the conversion rates of acetone plotted against times in accordance with Example VIII; Fig. 4 is a graph showing the conversion rates of acetone plotted against times in accordance with Example IX; Fig. 5 is a graph showing the conversion rates of acetone plotted against times in accordance with Example X; Fig. 6 is a graph showing the conversion rates of acetone plotted against times in accordance with Example XI; Fig. 7 is a graph showing the conversion rates of MH plotted against times in accordance with Example XII; Fig. 8 is a graph showing the conversion rates of GA plotted against times in accordance with Example XIII; DETAILED DESCRIPTION OF THE INVENTION In the invention, an acetylene alcohol compound, represented by the following chemical formula I: wherein R 1 and R 2 , which may be the same or different, each is a hydrogen atom, a linear or branched, saturated or unsaturated alkyl containing 1 to 16 carbon atoms, are prepared through the ethynylation in which an acetylene is condensed to a ketone containing the group -CH 2 -CO-CH 2 -, represented by the following chemical formula II: wherein R 1 and R 2 are as defined above. Some examples of the acetylene alcohol compounds prepared according to the invention are listed for their chemical structures, nomenclatures (IUPAC) and their abbreviated names in Table 1 with the corresponding ketones in Table 2, below. Solvents for the ethynylation in the present invention are aprotic dimethylformamide (hereinafter referred to as "DMF"), dimethyl sulfoxide (hereinafter referred to as "DMSO") and N-methylpyrrolidone (hereinafter referred to as "NMP"). The condensation is carried out in the presence of a base. For this, a strong basic, quaternary ammonium hydroxide anion exchange resin is employed in the invention and commercially available examples include tradenames Amberlite IRA-402 (OH), 410 (OH) and 900 (OH) of Rohm & Hass and tradename AB-17-8 (OH) made in Russia with preference to IRA-402 (OH), IRA-900 (OH) and AB-17-8 (OH). In order not to give a physically negative effect on the activity of the anion exchange resin, a milder temperature condition than those of conventional ethynylation processes is needed. In accordance with the present invention, the ethynylation is carried out at a temperature of 20 to 50 °C and preferably 30 to 40 °C. For example, if the reaction temperature is below 20 °C, the ethynylation is little proceeded. On the other hand, if the reaction temperature is over 50 °C, the anion exchange resin is likely to degrade. As for a pressure condition, it ranges from 981,3 - 2943,9 kPa (10 to 30 kg/cm 2 ) and preferably from 1471,9 - 2453,25 kPa (15 to 25 kg/cm 2 ). For example, if the ethynylation is carried out at below 981,3 kPa (10 kg/cm 2 ), the reaction proceeds slowly. On the other hand, if the pressure is over 2943,9 kPa (30 kg/cm 2 ), a physical deformation occurs on the anion exchange resin. Referring to Fig. 1, there is shown the structure of an apparatus in which acetylene alcohol compounds can be produced in a continuous process, according to the present invention. Acetylene gas is saturated in a reaction solvent to give an acetylene solution to be used later, in a first reactor 10. This acetylene saturation is very important in carrying out the ethynylation of the invention. Dissolution of acetylene in a solvent to be used may be accomplished by saturating acetylene gas in a cooled solvent under a low pressure or by applying the gas pressure of acetylene into the reactor containing a solvent at an ordinary temperature or a saturation-desired temperature. Simultaneous operation of a stirrer is helpful in increasing the solubility of the acetylene to some extent. Preferred conditions for the preparation of saturated acetylene solutions are given in Table 3, below. Saturation Temp. (°C) Solvents Saturation Press. (Kg/cm 2 ) -10∼-20 NMP, DMF 0.5∼2.0 (49,065∼196,26 kPa) -5∼0 NMP, DMF 4.0∼9.0 (392,52∼883,17 kPa) 23∼25 NMP, DMF,DMSO 6.0∼10.0 (588,78∼981,3 kPa) DMSO is excluded when the saturation is performed at low temperatures because it has a high melting point. Turning now to Fig. 1, the acetylene saturated solution thus prepared is provided to a mixer 30 with the aid of a first metering pump 20. Simultaneously, a second metering pump 40 is operated to provide a ketone reactant to the mixer 30 in which the reactants are, then, mixed to a desired concentration. The resulting mixture is transferred to a second reactor 60 filled with anion exchange resins, in which condensation occurs under the conditions set to a temperature of 20 to 50 °C and a pressure of 981,3 - 2943,9 kPa (10 to 30 kg/cm 2 ). This pressure can be controlled with a valve 70. In order to reuse unreacted acetylene, it is removed from the reaction mixture by a thin film evaporator 80. Following being neutralized by the treatment with KHSO 4 , the reactant mixture which remains unreacted is used to analyze the conversion rates of the ketones used and the corresponding selectivities for alcohols by gas-liquid chromatography. Two reactors 60 which are filled with the anion exchange resin are arranged in parallel so that they are alternatively used for continuous processing. That is, when, during working, one of them starts to show a reduced activity of its filled anion exchange resin as measured by the conversion rate of ketone, the flow of the reactant mixture is directed to the other reactor 60, so that the condensation reaction continues to proceed. While one of the two reactors 60 is working, the other is regenerated, thereby producing the object compounds efficiency. Useful anion exchange resins in the present invention are those which have OH active groups. If commercially available ones have C1 active groups, they should be converted to a hydroxide (OH) type. The procedure for this conversion is as follows: ion exchange resins of C1 type are placed in the second reactor and treated with a 5wt% solution of NaOH or KOH in methanol for a time, followed by flowing a reaction solvent for a time to replace the methanol solution. After the anion exchange resins are filled in the second reactor, the resins themselves volumetrically swell to an extent as the reaction proceeds. Thus, only up to 80 vol % of the reactor should be filled with the ion exchange resins in order to prevent a situation wherein the pressure increase, resulting from the volume expansion of the resins, might deleteriously affect the reaction. The ketones are used at an amount of 0.2 to 3.0 moles per mole of the acetylene while the solvent ranges, in molar ratio, from 1.0 to 4.0. To measure the effect of reaction time, the condensation was carried out in the wide LHSV (liquid hourly space velocity) range of 0.1 to 5.0. Herein, LHSV is the ratio of the volume of the reactant fed per hour to the volume of the catalyst filled in the reactor, as defined by the following mathematical equation I: [Mathematical equation I] LHSV= Vol. of Reactant Solution fed per hour Vol. of Catalyst After completion of the reaction, the desired products are isolated and purified through a series of processes, including removal of unreacted acetylene from the reactant mixture, extraction of the solvent, and distillation, fractional distillation or extraction according to the boiling points of the products. A better understanding of the present invention may be obtained in light of following examples which are set forth to illustrate, but are not to be construed to limit, the present invention. ION EXCHANGE RESIN TREATMENT EXAMPLE I Ion Exchange Resin IRA-402 (OH ) 40 ml of the anion exchange resin was filled in a tubular reactor 60 cm long with an inner diameter of 19 mm (see Fig. 1), followed by continuously flowing methanol for 20 to 25 hours into the reactor to remove the moisture present in the resin. Under the control of a metering pump, the methanol was introduced at an amount of 0.2 to 0.25 ml per hour per ml of ion exchange resin. The methanol which came out of the reactor was periodically analyzed for its moisture content. When the moisture content in the methanol was maintained at 0.3 wt% or less, the feed of the methanol was stopped. The methanol fractions passed out of the reactor were pooled and stored for reuse. Thereafter, a solvent to be used for acetylene saturation and condensation reaction was provided at a flow rate of 50 ml/hour for 10 hours with the aid of a metering pump, so as to wash the ion exchange resin. ION EXCHANGE RESIN TREATMENT EXAMPLE II Ion Exchange Resin IRA-900 (OH ) The resin was treated in the same manner as that of Treatment Example I. ION EXCHANGE RESIN TREATMENT EXAMPLE III Ion Exchange Resin IRA-410 (OH ) The resin was treated in the same manner as that of Treatment Example I. ION EXCHANGE RESIN TREATMENT EXAMPLE IV Ion Exchange Resin AB-17-8 (OH ) The resin was treated in the same manner as that of Treatment Example I. ION EXCHANGE RESIN TREATMENT EXAMPLE V Ion Exchange Resin IRA-402 (Cl ) 40 ml of the anion exchange resin was filled in the same tubular reactor as that of Treatment Example I, followed by continuously flowing a 5wt% solution of KOH or NaOH in methanol for 20 to 25 hours into the reactor to replace the Cl ions of the ion resin with OH ions. The solution was flowed under the control of a metering pump. After being dried at 50 °C in a vacuum condition, the resin was re-washed with a solvent to be used for acetylene saturation and condensation reaction for 10 hours with the aid of a metering pump. It was preferred that the solvent flowed at a rate of 50 ml/hour. ION EXCHANGE RESIN TREATMENT EXAMPLE VI Ion Exchange Resin IRA-900 (Cl ) The resin was treated in the same manner as that of Treatment Example V. ION EXCHANGE RESIN TREATMENT EXAMPLE VII Ion Exchange Resin IRA-410 (Cl ) The resin was treated in the same manner as that of Treatment Example V. ION EXCHANGE RESIN TREATMENT EXAMPLE VIII Ion Exchange Resin AB-17-8 (Cl ) The resin was treated in the same manner as that of Treatment Example V. ION EXCHANGE RESIN REGENERATION EXAMPLE I When the conversion rate of ketone, after the condensation reaction proceeded for a time, was reduced down to a predetermined level in comparison with that of the initial reaction stage, the provision of the reactant mixture was suspended in order to regenerate the ion exchange resins. The restoration of the activity of the resins comprised continuously feeding a 5wt% solution of KOH or NaOH in methanol while preferably maintaining the volume ratio of the ion exchange resins to the 5wt% solution at 1:4. By using a metering pump, the alkali methanol solution was continuously provided at a flow rate of 20 to 50 ml/hour for 8 to 9 hours. After completion of the regeneration, methanol was continuously introduced to the ion exchange resins to remove the alkali methanol solution present therein. When the eluant passed from the resins was neutral (about pH 7.0), the methanol introduction was stopped. Thereafter, an aprotic solvent to be used for acetylene gas saturation was fed preferably at a flow rate of 50 ml/hour for 10 hours with the aid of a metering pump, so as to wash the ion exchange resins. ACETYLENE SATURATED SOLUTION PREPARATION EXAMPLE A predetermined amount of a solvent to be used was poured in the first high pressure reactor equipped with a stirrer, a manometer and a thermometer. The solvent was maintained at a desired temperature with the aid of a heating medium while stirring. Acetylene gas in a cylinder was added in bubble form to saturate the solvent at a desired concentration which was, then, maintained by applying the appropriate pressures of acetylene gas according to reaction temperatures. The content of acetylene in the reactant mixture was quantitatively measured by use of the Illosvay solution. Analysis Principle The quantitation of the dissolved acetylene was based on the reaction between the copper acetylide (Cu 2 C 2 ) formed from acetylene and an acidic solution of ferric (III) salt, as shown in the following reaction formula II: [Reaction Formula II] Cu 2 C 2 + Fe 2 (SO 4 ) 3 + H 2 SO 4 - 2FeSO 4 + 2CuSO 4 + C 2 H 2 The quantity of acetylene could be measured by titrating the formed ferrous (II) salt with a standard KMnO 4 solution. On the whole, one mole of Cu 2 C 2 reacts correspondingly with two equivalents of KMnO 4 . The free acetylene after the reaction has no affect on the titration. Preparation of Analysis Reagents a) Standard acid solution of Fe 2 (SO 4 ) 3 100 g of Fe 2 (SO 4 ) 3 was dissolved in 200 ml of conc. sulfuric acid, followed by adding distilled water to a final 1 liter. b) Illosvay reagent In a 50 ml flask was placed 0.75 g of CuCl 2 •3H 2 O which was, then, well dissolved with a small amount of distilled water. 1.5 g of NH 4 Cl was added in the flask, followed by the slow addition of 3 ml of a 20 to 21 weight % aqueous solution of ammonia in water. The resulting mixture was well dissolved before the addition of distilled water to a final volume of 50 ml. At this time, the color of the solution was disappeared. Analysis Procedure i) 35 to 40 ml of a solvent (NMP, DMF or DMSO) in a flask was cooled down to 0 to 10 °C for NMP and DMF or to 15 to 16 °C for DMSO before 1 to 1.5 ml of a sample was dissolved. After the dissolving, the solution had to be weighed to the accuracy of the order of 0.01 g. Later, it was weighed, again. ii) While stirring the solution with care, 10 to 15 g of the solution was taken (with an accuracy of the order of 0.01 g) and then, added with about 20 to 25 ml of the Illosvay reagent to give red colored Cu 2 C 2 precipitates. iii) After being taken with a glass filter in a nitrogen atmosphere to prevent acetylide contact with the air, the precipitates were thoroughly washed many times with distilled water (to completely remove hydroxyamine). The perfection of the washing could be recognized from the situation that, when a drop of the KMnO 4 solution was added, the solution remained red for 30 seconds or more. iv) The precipitates were dissolved in 25 ml of the Fe 2 (SO 4 ) 3 standard acidic solution to give a green solution which was, then, accurately titrated with a 1N KMnO 4 . v) The acetylene content was calculated according to the following mathematical equation II: [Mathematical equation II] % C 2 H = 260.4 VKP o 2000 P s ( P l - P s ) wherein P o is the total weight of the solution (solvent + reaction mixture sample), P 1 is the weight of the net solvent (solution mixed upon extraction of sample), P s is the weight of the sample used for the Illosvay reaction, V is the volume of the KMnO 4 solution consumed for titration, K is a correction factor for the KMnO 4 solution. EXAMPLE I : Effect Upon Reactant Mixture Composition In the ethynylation of condensing acetylene to ketone according to the present invention, the relative concentrations of the reactants have a great influence on the conversion rate of ketone and the selectivity for the desired products, acetylene alcohol compounds. It is also well known that acetylene is limitatively saturated in a given volume of a solvent at a constant temperature under a constant pressure. Accordingly, the ethynylation results are greatly dependent on the molar ratio of acetylene to ketone. In this example, the reaction results were monitored according to the change in the composition of the reactants, acetylene and ketone, and the solvents. In the reactor (60 cm long with an inner diameter of 19 mm)of the continuous process apparatus of Fig. 1 was filled 40 ml of anion exchange resin AB-17-8 (OH) . This resin was treated in the same manner as that of Treatment Example IV, followed by slowly feeding the acetylene-saturated solution and ketone to the reactor. NMP was used as a reaction solvent. The saturation of acetylene was in the low temperature course (-10∼-12 °C) shown in Table 3, above. The reaction was carried out at 40 °C under a pressure of 1962,6 kPa (20 kg/cm 2 ) with use of acetone as the ketone reactant. The reaction results are given in Table 4, below. Test No. Molar Ratio LHSV Conversion of Acetone (%) Selectivity for DMEC(%) Acetylene Acetone NMP 1 1.0 2.34 2.34 0.33 38.8 >98 2 1.0 1.18 2.37 0.40 46.5 >98 3 1.0 1.41 2.37 0.40 72.5 >98 4 1.0 2.36 2.35 0.46 51.1 >98 5 1.0 0.97 2.36 0.46 73.3 >98 6 1.0 0.44 2.37 0.46 79.6 >99 7 1.0 0.90 2.34 0.20 85.1 >99 8 1.0 0.50 1.55 0.20 91.2 >98 The selectivity for the product, 2-methyl-but-3-yn-2-ol (DMEC), was determined on the basis of the reacted amount of the acetone by gas chromatography. In the reaction, LHSV and the molar ratio of acetylene to acetone to the solvent are used as variable parameters whereas reaction temperature and pressure are constant parameters. It is apparent from the data of Table 4 that the conversion rate of acetone increases as the stoichiometry of the acetone compared to the acetylene is lower if the other parameters, including LHSV, reaction temperature, pressure and moles of NMP, are constant. This means that, because the amount of the acetylene saturated in a given volume of the solvent is constant under a given condition, the reaction better proceeds as the mole number of the acetone used is less than that of the acetylene. Particularly, where the molar ratio of acetone to acetylene is below 1, the conversion rate of acetone is maintained at above 70%. The simple change of the solvent amount affects the saturation of the acetylene, but has no effect on the conversion rate of acetone or the selectivity for DMEC. In contrast, when LHSV, which is connected with reaction time, was changed, different reaction results came about. The smaller the LHSV, that is, the smaller the amount of the treated reactants per volume of the ion exchange resin per hour, the greater the conversion rate of acetone. In other words, as the treatment time is longer, the conversion rate of acetone increases. Accordingly, it is thought that the ethynylation should be carried out at an LHSV of 0.5 or less and at a molar ratio of acetylene to acetone to solvent of 1.0:0.5-1.0:1.5-3.0 in order to maintain the conversion rate of acetone at 70% or more. Thus, unless particularly mentioned in subsequent relevant reactions, the molar ratio of acetylene to acetone to solvent is on the order of 1.0:0.5:1.5-2.5. Under this condition, the effects of the other parameters will be compared. EXAMPLE II : Solvent Effect The same procedure as in Example I was repeated, except that DMF, instead of NMP, was used as a solvent. Acetylene-saturated NMP solutions were prepared by following the instruction shown in Table 3, above. The data which were obtained through preparative experiments in the same reaction conditions, show that, if the acetylene is used at a constant amount, similar results were attained for the conversion rate of ketone and for the selectivity for acetylene alcohol compound, each, irrespective of the kinds of solvent. The ethynylation was carried out in the same conditions, but with different solvents. The results were given in Table 5, below. Solvent Molar Ratio LHSV Conversion of Acetone (%) Selectivity for DMEC(%) Acetylene Acetone Sol. NMP 1.0 0.5 1.55 0.2 91.2 >98 DMF 1.0 0.5 1.55 0.2 90.0 >98 As apparent from Table 5, merely different solvents within an aprotic solvent category have almost no effect on the conversion rate of acetone and the selectivity for DMEC. From this result, the solvents used in the invention are aprotic with preference to NMP, DMF and DMSO. In subsequent Examples, any solvent of NMP, DMF and DMSO could be employed. EXAMPLE III: Effect Upon Change in LHSV Generally, reaction time is an important parameter of a reaction. In this Example, the effect by the change in reaction time was obtained at various LHSV values because the information for the relation between the amounts of the reactants and of the ion exchange resins is very important in performing the continuous process of the invention. As aforementioned in the mathematical equation I, LHSV is defined as the volume of reactant which is treated by a unit volume of catalyst for one hour. In order to consider the condensation of acetylene to ketone in the aspect of reaction rate, the reaction results were monitored according to LHSV change. From the data of Test. Nos. 5 and 7 of Table 4 in Example I, it is known that an increase in LHSV causes a significant reduction in ketone conversion level if the composition comprising the reactants and the solvent is constantly kept. Consequently, the larger the volume of the reactants which is treated per hour by a unit volume of the anion exchange resins, that is, the shorter the contact time between the anion exchange resin and the reactants, the lower the conversion level of ketone. In order to confirm this consequence, the reactant mixture was flowed through anion exchange resin IRA-402 (OH) in an LHSV range of 0.1 to 0.5 while other parameters kept constant. Some results are given in Table 6, below. LHSV Molar Ratio Conversion of Acetone (%) Selectivity for DMEC(%) Acetylene Acetone DMF 4 1.0 0.5 1.92 56∼74 >98 1 1.0 0.5 1.92 69∼78 >98 0.5 1.0 0.5 1.92 83∼86 >98 0.2 1.0 0.5 1.92 88∼92 >98 As shown in Table 6, the conversion of acetone into DMEC is improved as LHSV decreases, that is, as the reaction time is longer. And, the LHSV useful for the continuous production of acetylene alcohol compounds according to the present invention, ranges preferably from 0.2 to 4.0. EXAMPLE IV : Effect Upon Kinds of Ion Exchange Resin In the Example, experiments were performed for that which ion exchange resins have some degree of influence on the continuous ethynylation of the invention. Strongly basic anion exchange resins, especially, strongly basic, quaternary ammonium hydroxide anion exchange resins, were selected. The strongly basic quarternary ammonium hydroxide anion exchange resins suitable for use in the process of the present invention are those in which nitrogen atom is attached to three alkyl groups and to a methylene group, the methylene group being attached to a monocyclic aromatic group which is a constituent part of a cross-linked organic polymer or to the phenyl group of poly-stylene resin, taking account of activity and physical stability. Of the strongly basic, anion exchange resins having such structures, commercially available were preferably IRA-402 (OH), IRA-900 (OH) and AB-17-8 (OH). For the test of these anion exchange resins, the continuous production of DMEC through condensation of acetone and acetylene was considered as a model reaction. The test was carried out at 40 °C under a pressure of 1962,6 kPa (20 kg/cm 2 ) by using NMP or DMF as a solvent with the molar ratio of acetylene to acetone to the solvent being set to 1.0:0.5:1.92. When LHSV=0.2, 1.0 and 4.0, the results according to the anion exchange resins are given in Table 7, below. LHSV Conversion Rate of Acetone (%) Selectivity for DMEC (%) AB-17-8 IRA-402 IRA-900 AB-17-8 IRA-402 IRA-900 0.2 85-91 88-92 89-93 >97 >98 >98 1.0 70-77 69-77 71-79 >97 >97 >98 4.0 55-74 56-74 59-76 >97 >98 >98 As apparent from Table 7, the three strongly basic anion exchange resins provide similar results irrespectively of their kinds. That is, the conversion rates of acetone and the selectivities for DMEC according to the resins are within the acceptable error range at a given LHSV if the other conditions are constantly maintained. Therefore, if the life span of the resin is not taken into account, the three resins, IRA-402 (OH), IRA-900 (OH) and AB-17-8 (OH), all are useful for the continuous ethynylation of the present invention. EXAMPLE V: Production of Acetylene Alcohol Compounds by Continuous Process-1 In the above examples, the ethynylation condition under which acetylene alcohol compounds are efficiently produced by condensing ketones and acetylene was found to include a strongly basic, quaternary ammonium hydroxide anion exchange resins such as IRA-402 (OH), IRA-900 (OH) and AB-17-8 (OH), an aprotic solvent such as DMF, NMP and DMSO, 1.0:0.2-3.0:1.0-4.0 and preferably 1.0:0.5-1.0:1.5-3.0 for the molar ratio of acetylene to ketone to a solvent, 40 °C for reaction temperature, and 1962,6 kPa (20 kg/cm 2 ) for reaction pressure. In this example, some ketones were used to produce acetylene alcohol compounds under the above condition in a continuous process using the apparatus of Fig. 1, so as to judge its commercial applicability. The reaction temperature and pressure were fixed at 40 °C and 20 kg/cm 2 . Acetylene was saturated in DMF and the reactant mixtures were passed through IRA-402 (OH). The results are given in Table 8, below. Ketones Molar Ratio LHSV Product Conv. (%) Selectivity (%) HC≡CH Ketone DMF Acet. 1.0 0.50 1.92 0.20 DMEC 88-92 >98 MH 1.0 0.56 2.48 0.28 DHL 79-87 >97 GA 1.0 0.53 2.48 0.30 DHN 79-83 >99 PT 1.0 0.53 2.35 0.28 DHiP 85-98 >99 FA 1.0 0.20 0.30 0.30 GDHL 75-80 >99 As shown in Table 8, the conversion of ketone was maintained at a range of 75-90 % regardless of the kinds of ketone when the ethynylation was carried out in a given reaction condition with little fluctuation of LHSV (0.2-0.3). That is, regardless of the molecular weights and chemical structures of the ketones used, similar results, including the conversion rate of ketone and the selectivity for acetylene alcohol compounds, are obtained if the reaction conditions are consistent. Thus, similar, good results can be obtained with indifference to the kinds of ketones provided that the molar ratio of the composition is maintained appropriately in a given reaction condition. EXAMPLE VI: Production of Acetylene Alcohol Compounds in Continuous Process-2 This example pertains to the effect resulting from use of a different solvent and acetylene solution. The same procedure as in Example V was repeated, except that NMP, instead of DMF, was used and the low temperature route was taken for the saturation of acetylene. The reactant mixtures were passed through ion exchange resin IRA-402 (OH). Results are given in Table 9, below. Ketones Molar Ratio LHSV Product Conv. (%) Selectivity(%) HC≡CH Ketone NMP Acet. 1 0.66 1.92 0.21 DMEC 83∼90 >98 MH 1 0.5 2.63 0.14 DHL 75∼85 >98 GA 1 0.28 1.50 0.17 DHN 85∼88 >99 PT 1 0.49 1.96 0.25 DHiP 80∼88 >99 As shown in Table 9, similar results were obtained even when the solvent was changed from DMF to NMP and the acetylene was differently saturated. That is, the conversion rates of ketones and the selectivities for corresponding acetylene alcohol compounds were similar to those of Example V. Therefore, these results confirmed again that the method for producing acetylene alcohol compounds in a continuous process, according to the present invention, brings about similar results regardless of the kinds of solvents used and how to saturate acetylene. EXAMPLE VII: Reaction Temperature Effect-1 In this example, there was investigated what influence the change in reaction temperature had on the continuous ethynylation of the present invention. Generally, the temperature for the ethynylation should be below the maximum temperature at which strongly basic, anion exchange resins can work. Thus, experiments were carried out at 20 °C, 30 °C and 40 °C while the conversion rates of ketones were monitored according to time in a given reaction condition. For this, the LHSV was set to 4, a very severe condition, because low values of LHSV, although they allow high conversion rates of ketones, require too much time consumption in obtaining information for reaction tendency. As a model reaction, DMEC production through the condensation of acetylene to acetone was taken. First, this ethynylation was performed by passing the reactant mixtures through anion exchange resin IRA-402(OH) at 30 °C and 40 °C. The conversion rates according to time were monitored and the results are shown in Fig. 2. Referring to Fig. 2, the 30 °C and 40 °C conversion rate curves both are in the range of 65-75% for the early 10 hours. Thereafter, the conversion rates gradually decrease with a greater declination in experiment at 40 °C than in at 30 °C. That is, from the point that the reaction continued for 10 hours, more acetone is converted to DMEC at 30 °C than at 40 °C. Therefore, the anion exchange resin IRA-402 (OH) may be used in the temperature range of 30-40 °C, but 30 °C is better when taking the anion exchange resin's capacity of maintaining its activity into account. EXAMPLE VIII : Reaction Temperature Effect-2 The same procedure as in Example VII was repeated, except that IRA-900 (OH), instead of IRA-402 (OH), was used. The conversion rates according to temperatures 20 °C, 30 °C and 40 °C were plotted against times. The results are given in Fig. 3. With reference to Fig. 3, the 30 °C and 40 °C conversion rate curves show the same behaviors as those of IRA-402 (OH) of Example VII. That is, the conversion rate of acetone was maintained at 65-75 % for 10 hours after reaction initiation and, thereafter, the conversion rate of acetone at 30 °C gradually decreased while the 40 °C curve showed a sharp drop. For 20 °C, the early conversion rate of acetone is lower (55-65 %), compared with those at 30 °C and 40 °C. Moreover, the early acetone conversion rate could be maintained for only 3 hours or less. From that time, the conversion rate sharply dropped. Therefore, the anion exchange resin IRA-900 (OH) may be used in the temperature range of 30-40 °C, but 30 °C is better when taking the anion exchange resin's capacity of maintaining its activity into account. EXAMPLE IX : Test for Life Time of Ion Exchange Resin-1 The activity maintenance time of anion exchange resin in the ethynylation of acetylene and ketone in accordance with the present invention, that is, the time for which an anion exchange resin can maintain a desired level of the conversion rate of ketones, is very important for applying the continuous process of producing acetylene alcohol compounds of the present invention for commercial ends. Anion exchange resins IRA-402 (OH), IRA-900 (OH) and AB-17-8 (OH) were tested for how long they could maintain their useful activity, that is, their available life time, when they were regenerated. Tests were executed in a severe treatment condition (LHSV=4) and an optimal treatment condition (LHSV=0.2). Under the conditions given in Table 10, below, anion exchange resin IRA-402 (OH) was used for the ethynylation of acetylene and acetone. Molar Ratio LHSV Temp. (°C) Press. (Kg/cm 2 ) HC≡CH Acetone NMP 1 0.5 2.37 0.2 40 20 (1962,6 kPa) Referring to Fig. 4, there is a curve showing the change of conversion rate with reaction time when using IRA-402 (OH). As shown in Fig. 4, the conversion rate of acetone was stably maintained at above 75% for about 160 hours when LHSV=0.2. From the point that the reaction continued for 160 hours, the conversion rate of acetone started to decrease below 65%. At this time, the resin underwent the same regeneration as in the above Regeneration Example and reused. No noticeable difference in the early conversion rate was shown between before and after the regeneration. The early conversion rate was still retained by the resin which underwent the regeneration procedure several times. That is, the ethynylation was effectively performed for about 1,500 hours. EXAMPLE X : Test for Life Time of Ion Exchange Resin-2 As experienced in Example IX, the study on the life time of anion exchange resins under the condition LHSV=0.2 is difficult because it requires too much time. In this example, the ethynylation was performed in a severe condition, LHSV=4.0. Other conditions are given in Table 11, below. Molar Ratio LHSV Temp. (°C) Press. (Kg/cm 2 ) HC≡CH Acetone NMP 1 0.5 1.92 4.0 40 20 (1962,6 kPa) The test result is given in Fig. 5. As shown in Fig. 5, the conversion rate of acetone was found to maintain about 65-75 % for 10 hours. This result is almost consistent with the above result. That is, the 10 hours at LHSV=4.0 is in proportion to the maintenance time (about 160 hours) of Example IX (LHSV=0.2). At the point that the conversion rate of acetone was reduced down to about 65%, the anion exchange resin was regenerated in the same manner as in the above and subsequently, tested for activity. The anion exchange resin could maintain its activity for 50 hours or more through four-time regeneration. Even after this time, the resin could be twice regenerated to have 55-65 % activity for 20 hours in total. EXAMPLE XI : Test for Life Time of Ion Exchange Resin-3 Ethynylation was carried out in a similar manner to that of Example X, except that IRA-900 (OH) was used instead of IRA-402 (OH). The result is given in Fig. 6. Compared to IRA-402 (OH), IRA-900 (OH), as shown in Fig. 6, has a similar catalyst life time, but a longer time for which the early conversion rate of acetone is maintained through regeneration. Via nine rounds of regeneration, the IRA-900 (OH) maintained 65-75% activity for about 100 hours in total. This maintenance time is twice as long as that of IRA-402 (OH). Therefore, IRA-900 (OH) is more efficient for the invention than IRA-402 (OH). EXAMPLE XII : Test for Life Time of Ion Exchange Resin-4 In this example, MH was used as a ketone reactant to produce DHL while AB-17-8 (OH) was selected as an anion exchange resin. The ethynylation via a continuous process was carried out under the conditions indicated in Table 12, below. Molar Ratio LHSV Temp. (°C) Press. (Kg/cm 2 ) HC≡CH MH NMP 1 0.5 2.63 0.15 40 20 (1962,6 kPa) The result is given in Fig. 7. As shown in Fig. 7, the conversion rate of MH was increased up to 78-80% at the point that the reaction continued for 150 hours. From this point, the conversion rate was gradually reduced down to about 63%. At this time, the feeding of the reactant mixture was stopped, followed by the regeneration of the resin. Re-operation of the process showed that the regenerated resin attained and maintained its previous conversion rate. EXAMPLE XIII : Test for Life Time of Ion Exchange Resin-5 In this example, GA was used as a ketone reactant to produce DHN while AB-17-8 (OH) was selected as an anion exchange resin. The ethynylation via a continuous process was carried out under the conditions indicated in Table 13, below. Molar Ratio LHSV Temp. (°C) Press. (Kg/cm 2 ) HC≡CH GA NMP 1 0.25 1.61 0.18 40 20 (1962,6 kPa) The result is given in Fig. 8. As shown in Fig. 8, the conversion rate of GA was maintained at 80 to 85% for 300 hours or more. As the conversion rate was gradually reduced from that time, the anion exchange resin was regenerated, after which the reactant mixture was re-provided. This reoperation of the process showed that the regenerated resin attained and maintained its early conversion rate. The ethynylation could be continuously performed without replacing the resin with a fresh one. EXAMPLE XIV : Test for Life Time of Ion Exchange Resin-6 In this example, PT was used as a ketone reactant to produce DHiP while AB-17-8 (OH) was selected as an anion exchange resin. The ethynylation via a continuous process was carried out under the conditions indicated in Table 14, below. Molar Ratio LHSV Temp. (°C) Press. (Kg/cm 2 ) HC≡CH PT NMP 1 0.25 1.61 0.25 40 15 (1471,95 kPa) The conversion rate of GA was maintained at 80% or higher for 160 hours. As the conversion rate was gradually reduced from that time, the anion exchange resin was regenerated, after which the reactant mixture was re-provided. This reoperation of the process showed that the regenerated resin was increased in the early conversion rate range. Therefore, The ethynylation could be continuously performed without replacing the resin with a fresh one. As described hereinbefore, acetylene alcohol compounds, very valuable in a commercial aspect, can be produced at high yield with environmental favorableness by condensing acetylene to ketones in an aprotic solvent in the presence of heterogeneous, strongly basic, quaternary ammonium hydroxide anion exchange resin. For successful and efficient ethynylation of acetylene with the ketones containing the group -CH 2 COCH 2 -, preferable molar ratios of acetylene to ketone to solvent are in the range of 1.0:0.2-3.0:1.0-4.0. Experiments at the temperature range of 20 to 50 °C showed that desired results for the conversion rate of ketones and the selectivity for acetylene alcohol are obtained at 30 to 40 °C. As for a pressure condition, it ranges from 981,3 - 2943,9 kPa (10 to 30 kg/cm 2 ). As the aprotic solvent, NMP, DMF and DMSO are effective and all give similar results. After the ethynylation was carried out in the LHSV, defined as the volume of the reactant passed through the unit volume of anion exchange resin in the range of 0.1 to 5.0, there was obtained the data which show an LHSV of 0.2 to 4.0 is preferred. In order to carry out the production of acetylene alcohol compounds in a continuous process, two or more batches of the anion exchange resins are employed : one batch of the strong basic, heterogeneous quaternary ammonium hydroxide anion exchange resin is operated while the other batch is regenerated with the aid of an alkali methanol solution. The regenerated resin is restored to its original activity level. Consequently, the commercially useful acetylene alcohol compounds can be continuously produced at high conversion rate with high selectivity therefor, according to the present invention. The present invention has been described in an illustrative manner, and it is to be understood the terminology used is intended to be in the nature of description rather than of limitation. Many modifications and variations of the present invention are possible in light of the above teachings. Therefore, it is to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

Claims: A method for producing an acetylene alcohol compound in a continuous process, comprising the steps of: (i) saturating an acetylene gas in an aprotic solvent selected from the group consisting of dimethylformamide, dimethyl sulfoxide and N-methylpyrrolidone in a first reactor in the absence of liquid ammonia and alkali metal hydroxide; (ii) mixing the saturated acetylene solution with a ketone containing a CH 2 COCH 2 to form a reactant mixture of said acetylene, ketone and solvent in a molar ratio of 1.0:0.2-3.0:1.0-4.0; (iii) feeding the reactant mixture into one of a second and third reactor, said second and third reactors containing a strongly basic quaternary ammonium hydroxide anion exchange resin, at a liquid hourly space velocity in the range of 0.1 to 5.0; and (iv) reacting the reactant mixture in the presence of said resin at a temperature of 20 to 50°C. under a pressure of 981,3 - 2943,9 kPa (10 to 30 kg/cm 2 ); said second and third reactors being alternately operated to permit the regeneration of said resin in one reactor while said other reactor is being operated. The method as set forth in claim 1, wherein said quaternary ammonium hydroxide anion exchange resin having strong basicity has a structure in which each nitrogen atom is attached to three alkyl groups and to a methylene group, the methylene group being attached to a monocyclic aromatic group which is constituent part of a cross-linked organic polymer. The method as set forth in claim 1, wherein said quaternary ammonium hydroxide anion exchange resin having strong basicity has a structure in which each nitrogen atom is attached to three alkyl groups and to a methylene group, the methylene group being attached to the phenyl group of a polystyrene resin. The method as set forth in claim 1, wherein said temperature ranges 30 to 40°C. The method as set forth in claim 1, wherein said pressure ranges 1471,95 to 2453,25 kPa (15 to 25 kg/cm 2 ). The method as set forth in claim 1, wherein said molar ratio of acetylene to ketone to solvent is on the order of 1.0:0.5-1.0:1.5-3.0. The method as set forth in claim 1, wherein said reactant mixture is fed at an LHSV range of 0.2-4.0. The method as set forth in claim 1, wherein said ketone is represented by the following chemical formula II: [Chemical Formula II] wherein R 1 and R 2 , which may be the same or different, each is a hydrogen atom, a linear or branched, a saturated or unsaturated alkyl containing 1 to 16 carbon atoms. The method as set forth in claim 8, wherein said ketone is selected from the group consisting of 2-propanone, 6-methyl-hep-5-en-2-one, 6,10-dimethyl-undeca-5, 9-dien-2-one, 6, 10, 14-trimethyl-5,9,13-pentadecartrien-2-one, and 6,10,14-trimethyl-pentadecan-2-one. The method as set forth in claims 1, wherein said acetylene alcohol compound is selected from the group consisting of 2-methyl-but-3-yn-2-ol, 3,7-dimethyl-oct-6-en-1-yn-3-ol, 3,7,11-trimethyl-dodeca-6,10-dien-1-yn-3-ol,3,7,11,15-tetramethyl-6,10,14-hexadecatrien-1-yn-3-ol and 3,7,11,15-tetramethyl-hexadeca-1-yn-3-ol. The method as set forth in claim 1, wherein said anion exchange resin is treated with a solution of NaOH or KOH in methanol for a time for reuse.

Inventors: JUNG YOUNG GYUN, KANG YOUNG SUN, KIM CHANG KUK, KIM TAIK KEUN, LEE SIJOON, JUNG, YOUNG GYUN, KANG, YOUNG SUN, KIM, CHANG KUK, KIM, TAIK KEUN, LEE, SIJOON
Applicants: SK CORP, SK CORPORATION
Application year: 1999
Main classification: C07C29
IPC codes: C07C29, C07C33, B01J31, C07B61