GB2145076A - A process for producing 1,2-alkanediols - Google Patents
A process for producing 1,2-alkanediols Download PDFInfo
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- GB2145076A GB2145076A GB08321852A GB8321852A GB2145076A GB 2145076 A GB2145076 A GB 2145076A GB 08321852 A GB08321852 A GB 08321852A GB 8321852 A GB8321852 A GB 8321852A GB 2145076 A GB2145076 A GB 2145076A
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C29/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
- C07C29/03—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by addition of hydroxy groups to unsaturated carbon-to-carbon bonds, e.g. with the aid of H2O2
- C07C29/04—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by addition of hydroxy groups to unsaturated carbon-to-carbon bonds, e.g. with the aid of H2O2 by hydration of carbon-to-carbon double bonds
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C29/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
- C07C29/09—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by hydrolysis
- C07C29/095—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by hydrolysis of esters of organic acids
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C67/00—Preparation of carboxylic acid esters
- C07C67/04—Preparation of carboxylic acid esters by reacting carboxylic acids or symmetrical anhydrides onto unsaturated carbon-to-carbon bonds
- C07C67/05—Preparation of carboxylic acid esters by reacting carboxylic acids or symmetrical anhydrides onto unsaturated carbon-to-carbon bonds with oxidation
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Abstract
A continuous process for producing 1,2-alkanediols of the formula <IMAGE> wherein R is a straight-chain or branched-chain alkyl group having 2-10 carbon atoms, comprises reaction of an alkene of the formula R-CH = CH2 wherein R has the meaning defined above, with hydrogen peroxide and formic acid, and subsequent hydrolysis of the formed 1,2-alkanediol monoformate. The process comprises introducing continuously, in controlled amounts, the alkene of the formula II, hydrogen peroxide and formic acid, in a molar ratio of 1.0:1.0-1.5:0.5-10, at 20-100 DEG C into an equilibrium mixture obtained by reaction of these components in the aforementioned molar ratio; simultaneously continuously removing from the reaction mixture the corresponding amount of fully reacted mixture; and isolating from this, after hydrolysis of the formed 1 ,2-alkanediol monoformate, the 1,2-alkanediol of the above formula. The 1 ,2-alkanediols of the above formula can be used as intermediates for producing 1-( beta -arylethyl)- 1H-1,2,4-triazole ketals having an antimicrobial action and an action regulating plant growth.
Description
SPECIFICATION
A process for producing 1,2-alkanediols
The present invention relates to a process for producing 1,2-alkanediols of the formula I
wherein R is a straight-chain or branchedchain alkyl group having 2-10 carbon atoms.
The 1,2-alkanediols of the formula I are valuable intermediates for producing 1-(ss-aryl- ethyl)-1 H-1,2,4-triazole ketals having an antimicrobial action and an action regulating plant growth. These 1-(fl-arylethyl)-1 H-1,2,4- triazole ketals and the production and use thereof are described for example in the US
Patent Specification No. 4,079,062.Mentioned as a preferred representative of this class of substances is 1-[2-(2,4-dichlorophe- nyl)-4-n-propyldioxolan-2-ylmethyl]- 1 H- 1,2,4triazole, which is commercially sold under the name of TlL. It can be produced by reaction of -bromo-2,4-dichloroacetophenone with 1,2-pentanediol to give 2-bromomethyl-2 (2,4-dichlorophenyl)-4-n-propyldioxolane, and the further reaction thereof with 1 H-1,2,4triazole.
The procedure is known for converting 1alkenes, such as 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene and 1-oc- tadecene, by reaction with performic acid in formic acid as solvent, and subsequent alkaline saponification of the firstly formed 1,2alkanediol monoformates into the corresponding 1,2-alkanediols. The required performic acid in this case is not produced separately but directly in the reaction mixture. In this process, there is introduced at about 40'C into a mixture consisting of 1-alkene and formic acid, with stirring, the necessary amount of hydrogen peroxide, the amount of formic acid used being 10-30 mols per mol of 1-alkene, and the employed aqueous hydrogen peroxide being at a concentration of about 25% by weight. The reaction time under these conditions is 8-24 hours (cp. J.
Amer. Chem. Soc. 68(1946), 1504-1507).
This process is improved according to EP-A 25.940 in that 2-6 mols of formic acid are used per mol of alkene, and the hydrogen peroxide is employed at a concentration of 35-98 % by weight, the reaction being carried out at a temperature of 40-80"C.
There is described in DE-A 2,937,840 finally a process in which less than 2 mols of formic acid and less than 2 mols of hydrogen peroxide are used per mol of alkene, wherein the concentration of formic acid can be 20-100 % by weight, and the concentration of the employed hydrogen peroxide is below 50 % by weight.
All processes known hitherto are performed by adding the necessary amount of hydrogen peroxide, with vigorous stirring, to a mixture of 1-alkene and formic acid. This procedure is disadvantageous with respect to carrying it out on a large commercial scale because, on account of the low solubility of the 1-alkenes, required for producing the 1,2-alkanediols of the formula I, in formic acid, the starting mixture is present in 2 phases at the commencement of the reaction. The complete interixing of such mixtures, necessary for a smooth course of reaction, is very difficult when the process is carried out on a commercial scale, and can be achieved only with great expenditure.Furthermore, the known procedure for the reaction of lower 1-alkenes is disadvantageous also because it is necessary, on account of the low boiling point of these compounds, to perform the reaction either at very low temperatures or under pressure. It is therefore not possible with the known processes to produce the 1 ,2-alkanedi- ols of the formula I on a commercial scale in a simple and economical manner.
It has now been found that it is possible to avoid the aforementioned disadvantages and to produce the 1,2-alkanediols of the formula
I in a simple manner and with high yields by performing the reaction of the 1-alkene with hydrogen peroxide and formic acid in a reaction medium in the form of an equilibrium mixture maintained by reaction of these components.
The invention relates therefore to a continuous process for producing 1,2-alkanediols of the formula I by reaction of an alkene of the formula II
R-CH = CH2 (Il), wherein R has the meaning defined under the formula I, with hydrogen peroxide and formic acid, and subsequent hydrolysis of the formed 1,2-alkanediol monoformate, which process comprises introducing continuously, in controlled amounts, the alkene of the formula II, hydroen peroxide and formic acid, in a molar ratio of 1.0 :1.0-1.5 0.5-10, at 20-100"C into a reaction mixture obtained by reaction of these components in the aforementioned molar ratio simultaneously continuously removing from the reaction mixture the corresponding amount of fully reacted mixture; and isolating from this, optionally after decomposition of unreacted hydrogen peroxide and hydrolysis of the formed 1 ,2-alkanediol monoformate, the 1,2-alkanediol of the formula I.
Suitable 1-alkenes of the formula II are in particular: 1-butene, 2-methyl-I -propene (isobutylene), 1-pentene, 3-methyl-butene, 1-hexene, 2,3-dimethyl-l -butene, 3-methyl-l-pen- tene, 4-methyl-l-pentene, 1-heptene, 3-me thyl-1-hexene, 2,4-dimethyl-I -pentene, 1-oc- tene, 2,5-dimethyl-i-hexene, 1-nonene and 1 decene. Preferred among the aforementioned alkenes of the formula II are: 1-butene, 1pentene and 1-hexene. An especially preferred alkene of the formula II is 1-pentene.
The hydrogen peroxide can be used at a concentration of 25-100 % by weight. It is however preferably used at a concentration of 50-100 % by weight.
The formic acid is used according to the invention in concentrated form. The concentration of formic acid should as a rule be at least 70 % by weight, and it is advantageous to use a formic acid having a concentration of 75-100 % by weight. Particularly preferred is the use of essentially anhydrous formic acid, for example 98% formic acid.
The alkene of the formula II, hydrogen peroxide and formic acid are advantageously employed in the molar ratio of 1.0 1.05-1.4:1.0-4.0.
Preferred temperatures within the temperature range of 20-100"C are those between 30 and 80"C, and especially preferred are temperatures of 40-70"C. Under the reaction conditions according to the invention, a reaction time of 0.5-24 hours is as a rule required. The reaction in most cases can be performed in a time of 1-10 hours.
The equilibrium mixture serving as the reaction medium, which is maintained in the above-mentioned molar ratio by reaction of an alkene of the formula II with hydrogen peroxide and formic acid, can be produced by reaction of these components in the manner known from the literature stated in the foregoing. An equilibrium mixture of this kind can be produced particularly advantageously by introducing at 20-100"C, in controlled amounts, the alkene and the hydrogen peroxide simultaneously into the formic acid in the reaction vessel, the rate of addition being such that the concentration of the unreacted alkene is always equal to or lower than that at which the alkene is soluble in the reaction medium. This procedure has the advantage that the reaction medium always remains single-phase and clear, and can therefore be particularly easily handled.
The process according to the invention is performed, in the simplest case, in a reaction vessel fitted with heat-exchange surfaces, the reaction vessel being provided with dosing devices for the reaction components, as well as with an arrangement for the removal of an amount of fully reacted mixture corresponding to the amount of components being introduced in controlled quantities. There are advantageously used several reaction vessels connected together in the form of a stirrervessel cascade. The process according to the invention can be performed particularly advantageously in a circulating reaction system. A reaction system of this type is illustrated in the attached drawing (Fig. 1). It consists of a reaction vessel 1, which is fitted with a heatexchanger 2 connected to a thermostat 3.The reaction vessel 1 is also provided with a feed pipe 4, through which is fed, by means of a circulating pump 5, fresh reaction mixture.
The reaction vessel has an overflow 6, through which the reaction mixture flows into a collecting vessel 7, in which a constant filling height is maintained with the aid of a siphon 8. The collecting vessel 7 is connected through the pipe line 9 to the circulating lamp 5. 1-Alkene and formic acid are introduced into the pipe line 9, and hydrogen peroxide is fed into the feed pipe 4. The amount of fully reacted reaction mixture corresponding to the introduced amount of starting materials is removed through the siphon 8. The collecting vessel 7 is fitted with a condenser 10, by way of which readily volatile constituents are fed to an absorber. The time the reaction mixture remains in the reaction vessel 1 is governed by the ratio of the volume of the reaction vessel to the feed rate of the reactants. The time is advantageously 0.5-2 hours.
To set the reaction system into operation, it is firstly filled with a reaction mixture obtained by reaction of an alkene of the formula II with hydrogen peroxide and formic acid. For producing this reaction mixture, the alkene of the formula II, the hydrogen peroxide and the formic acid are preferably used in the same molar ratio as subsequently is used in carrying out the process of the invention. The introduction in controlled amounts of 1-alkene, formic acid and hydrogen peroxide is not started until reaction vessel and collecting vessel are filled with the reaction mixture.
The reaction mixture taken off through the syphon 8, the amount of which corresponds exactly to the introduced amount of starting materials, is advantageously freed from unreacted hydrogen peroxide. This can be effected by the addition of a reducing agent, such as sodium bisulfite, or catalytically, for example by passing the reaction mixture over a noble metal catalyst, for example platinum, deposited on a ceramic carrier. The unreacted formic acid is afterwards distilled off under reduced pressure, and the 1,2-alkanediol monoformate present in the residue is hydrolised.
This can be performed by slowly introducing the residue, obtained after the unreacted formic acid has been distilled off, into diluted sodium hydroxide solution. The 1.2-alkanediol of the formula I is then separated from the reaction mixture present after hydrolysis, advantageously by extraction with a solvent not miscible with water, for example toluene or ethyl acetate, and is obtained in the pure form by processing of the extract by distillation.
It is possible by the process according to the invention to produce 1,2-alkanediols of the formula I in a simple and economical manner and with excellent yields. A particular advantage of the process of the invention is that the reaction mixture remains a single phase mixture. A further important advantage of the process according to the invention is that also lower alkenes of the formula II, such as 1-butene, 1-pentene and 1-hexene, can be reacted, without the application of excess pressure, at temperatures which are clearly above the boiling point of these substances.
1-Pentene for example can be readily reacted under normal pressure at temperatures of up to 70"C without the substance volatilising out of the reaction mixture. The process according to the invention is suitable in particular also for the reaction of lower alkenes of the formula II. The yields obtainable by the process according to the invention are as a rule about 90% of theory.
The process according to the invention is further illustrated by the following Examples.
Example 1
Production of 1,2-pentanediol
There is firstly produced, by reaction of 1pentene, hydrogen peroxide (70%) and formic acid (98%) in the molar ratio of 1 :1.5 : 4, an equilibrium mixture which serves as reaction medium for the following reaction. This equilibrium mixture is produced by slowly introducing 1-pentene and hydrogen peroxide simultaneously at 40-55"C into the formic acid and, after completion of the addition, stirring the mixture at 55 C for a further one hour.
800 ml of this mixture (working volume of the reaction vessel) are fed into a circulating reaction vessel 1, fitted with circulating pump 5 and overflow syphon 8, and are heated, as they are being circulated, to 55"C. There are then introduced 40.0 g/h (0.57 mol/h) of 1pentene and 104.9 g/h (2.28 mol/h) of formic acid into the pipe line 9, and 31.8 g/h (0.656 mol/h) of hydrogen peroxide (70%) into feed pipe 4. An exothermic reaction occurs; the temperature is allowed to rise to 62-63"C, and, with a constant rate of addition of the components, it is held constant by means of the circlation thermostat 3. There are obtained during 8 hours, 1.413 kg of reaction mixture, wherein 1,2-pentanediol is largely present as monoformate.By evaporating off formic acid and water in vacuo, introducing the residue into 25% sodium hydroxide solution, separating the phases and fractionally distilling the organic phase, there are obtained 432.2 g (91% of theory) of 1,2pentanediol having a boiling point of 96-98 C/13 mbar.
Example 2
Production of 1,2-heptanediol
There is firstly produced by reaction of 1heptene, hydrogen peroxide (70%) and formic acid (98%) in the molar ratio of 1:1.5 : 4, an equilibrium mixture which serves as reaction medium for the following reaction. This equilibrium mixture is produced by slowly introducing 1-heptene and hydrogen peroxide simultaneously at 40-55"C into the formic acid and, after completion of the addition, stirring the mixture at 55"C for a further one hour.
800 ml of this mixture (working volume of the reaction vessel) are fed into a circulating reaction vessel 1, fitted with circulating pump 5 and with overflow siphon 8, and are heated, whilst being circulated, to 55"C.
There are then introduced 27.33 g/h (0.57 mol/h) of 1-heptene and 104.9 g/h (2.28 mol/h) of formic acid into the pipe line 9, and 31.8 g/h (0.656 mol/h) of hydrogen peroxide (70%) into feed pipe 4. An exothermic reaction occurs; the temperature is allowed to rise to 62-63"C, and, with a constant rate of addition of the components, it is held constant by means of the circulation thermostat 3.
There are obtained in 3 hours 366 g of reaction mixture, wherein 1,2-heptanediol is present largely as monoformate. By evaporating off formic acid and water in vacuo, introducing the residue into 25% sodium hydroxide solution, separating the phases and fractionally distilling the organic phase, there are obtained 98.7 g (89% of theory) of 1,2heptanediol having a boiling point of 132-133"C/18-20 mbar.
Claims (14)
1. A continuous process for producing a I ,2-alkanediol of the formula I
wherein R is a straight-chain or branchedchain alkyl group having 2-10 carbon atoms, by reaction of an alkene of the formula II
R-CH = CH2 (Il) wherein R has the meaning defined under the formula I, with hydrogen peroxide and formic acid, and subsequent hydrolysis of the formed 1 ,2-alkanediol monoformate, which process comprises introducing continuously, in controlled amounts. the alkene of the formula II, hydrogen peroxide and formic acid, in a molar ratio of 1.0:1.0-1.5 0.5-10, at 20-100"C into an equilibrium mixture obtained by reaction of these components in the aforementioned molar ratio; simultaneously continuously removing from the reaction mixture the corresponding amount of fully reacted mixture; and isolating from this, optionally after decomposition of unreacted hydrogen peroxide and hydrolysis of the formed 1,2alkanediol monoformate, the 1,2-alkanediol of the formula I.
2. A process according to Claim 1, wherein hydrogen peroxide is used at a.con- centration of 25-100 % by weight.
3. A process according to Claim 1, wherein hydrogen peroxide is used at a concentration of 50-100 % by weight.
4. A process according to Claim 1, wherein formic acid is used at a concentration of at least 70 % by weight.
5. A process according to Claim 1, wherein formic acid is used at a concentration of 75 % by weight.
6. A process according to Claim 1, wherein essentially anhydrous formic acid is used.
7. A process according to Claim 1, wherein the alkene of the formula ll, hydrogen peroxide and formic acid are used in the molar ratio of 1.0 :1.05-1.4 1.0-4.0.
8. A process according to Claim 1, wherein the reaction is performed at a temperature of 30-80'C.
9. A process according to Claim 1, wherein the reaction is performed at a temperature of 40-70"C.
10. A process according to Clam 1, wherein the employed alkene of the formula II is 1-butene, 1-pentene or 1-hexene.
11. A process according to Claim 1, wherein the employed alkene of the formula II is 1-pentene.
12. A process according to Claim 1, wherein the starting materials used are 1pentene, hydrogen peroxide having a concentration of 50-100 % by weight, and essentially anhydrous formic acid, and these starting materials are continuously reacted, in a molar ratio of 1.0 :1.05-1.4 1.0-4.0, at 40-70"C in a reaction medium in the form of an equilibrium mixture maintained in the aforementioned molar ratio by reaction of these components.
1 3. A process according to claim 1 substantially as described with reference to either of the Examples.
14. 1,2-Alkanediols of formula I when produced by a process claimed in any of the preceding claims.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB08321852A GB2145076A (en) | 1983-08-13 | 1983-08-13 | A process for producing 1,2-alkanediols |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB08321852A GB2145076A (en) | 1983-08-13 | 1983-08-13 | A process for producing 1,2-alkanediols |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB8321852D0 GB8321852D0 (en) | 1983-09-14 |
| GB2145076A true GB2145076A (en) | 1985-03-20 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08321852A Withdrawn GB2145076A (en) | 1983-08-13 | 1983-08-13 | A process for producing 1,2-alkanediols |
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| Country | Link |
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| GB (1) | GB2145076A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0183029A2 (en) * | 1984-11-24 | 1986-06-04 | Degussa Aktiengesellschaft | Continuous process for the preparation of 1,2-pentanediol |
| WO1999016733A1 (en) * | 1997-09-29 | 1999-04-08 | Basf Aktiengesellschaft | Method for producing vicinal diols or polyols |
| US7385092B2 (en) | 2004-12-15 | 2008-06-10 | Degussa Ag | Process for preparing alkanediols and alkanetriols having a vicinal diol group |
| CN103992207A (en) * | 2014-05-09 | 2014-08-20 | 常州大学 | Method for preparing vicinal diol by catalytic oxidation of alkene in hydrogen peroxide/cationic resin system |
| CN104926600A (en) * | 2015-05-12 | 2015-09-23 | 佛山市德品高新材料有限公司 | Method for synthesizing 1,2-pentanediol by one-pot method |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0025940A1 (en) * | 1979-09-19 | 1981-04-01 | Degussa Aktiengesellschaft | Process for the hydroxylation of olefinically unsaturated compounds |
| EP0025890A1 (en) * | 1979-09-19 | 1981-04-01 | Degussa Aktiengesellschaft | Process for the hydroxylation of low-chain aliphatic mono- or diolefines |
-
1983
- 1983-08-13 GB GB08321852A patent/GB2145076A/en not_active Withdrawn
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0025940A1 (en) * | 1979-09-19 | 1981-04-01 | Degussa Aktiengesellschaft | Process for the hydroxylation of olefinically unsaturated compounds |
| EP0025890A1 (en) * | 1979-09-19 | 1981-04-01 | Degussa Aktiengesellschaft | Process for the hydroxylation of low-chain aliphatic mono- or diolefines |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0183029A2 (en) * | 1984-11-24 | 1986-06-04 | Degussa Aktiengesellschaft | Continuous process for the preparation of 1,2-pentanediol |
| EP0183029A3 (en) * | 1984-11-24 | 1987-08-05 | Degussa Aktiengesellschaft | Continuous process for the preparation of 1,2-pentanediol |
| WO1999016733A1 (en) * | 1997-09-29 | 1999-04-08 | Basf Aktiengesellschaft | Method for producing vicinal diols or polyols |
| US6281394B1 (en) * | 1997-09-29 | 2001-08-28 | Basf Aktiengesellschaft | Method for producing vicinal diols or polyols |
| US7385092B2 (en) | 2004-12-15 | 2008-06-10 | Degussa Ag | Process for preparing alkanediols and alkanetriols having a vicinal diol group |
| CN103992207A (en) * | 2014-05-09 | 2014-08-20 | 常州大学 | Method for preparing vicinal diol by catalytic oxidation of alkene in hydrogen peroxide/cationic resin system |
| CN103992207B (en) * | 2014-05-09 | 2017-05-03 | 常州大学 | Method for preparing vicinal diol by catalytic oxidation of alkene in hydrogen peroxide/cationic resin system |
| CN104926600A (en) * | 2015-05-12 | 2015-09-23 | 佛山市德品高新材料有限公司 | Method for synthesizing 1,2-pentanediol by one-pot method |
| CN104926600B (en) * | 2015-05-12 | 2018-02-09 | 佛山市德品高新材料有限公司 | A kind of method of the pentanediol of one pot process 1,2 |
Also Published As
| Publication number | Publication date |
|---|---|
| GB8321852D0 (en) | 1983-09-14 |
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| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |