DE10305225A1 - Process for the preparation of 2,2'-dihydroxy-biphenyls - Google Patents

Abstract

Process for the preparation of a 2,2'-dihydroxy-biphenyl by oxidative coupling of two phenol molecules, which have a hydrogen atom in an o-position, by means of a peroxide at a temperature in the range from 140 to 180 ° C. and the peroxide is continuously fed to the same reaction mixture.

Description

The present invention relates to a process for the preparation of 2,2'-dihydroxybiphenylene by oxidative Coupling of two phenol molecules, the one in an o position have a hydrogen atom, by means of a peroxide, thereby characterized that you can implement at a temperature in the range from 140 to 180 ° C performs and the peroxide continuously feeds the reaction mixture.

2,2'-dihydroxy-biphenyls, such as 2,2'-dihydroxy-3,3 ', 4,4', 6,6'-hexamethyl-biphenyl, can known for the Production of bidentate phosphite ligands can be used.

For example, describes US 6,171,996 in Example 16 the reaction of one mole of 2,2'-dihydroxy-3,3 ', 4,4', 6,6'-hexamethyl-biphenyl with two moles of di- (o-methylphenoxy) -phosphorus- (III) - chloride to the compound designated there as ligand "P". This ligand "P" is then used according to Example 16A together with Ni (0) and zinc chloride for the hydrocyanation of 3-pentenenitrile to give a mixture of adiponitrile, methylglutarodinitrile and ethylsuccinodinitrile.

For the preparation of 2,2'-dihydroxy-3,3 ', 4,4', 6,6'-hexamethyl-biphenyl US 6,171,996 in Example 16 to the method described for the preparation of 3,3 ', 5,5'-tetramethyl-2,2'-biphenol according to: WW Kaeding, J. Org. Chem., 1963, 28, 1063-1067.

According to WW Kaeding, J. Org. Chem., 1963, 28, 1067, only 29 g of a crude product contaminated with an oil are converted into 150 g of 3,3 ', 5,5'-tetramethyl-2,2'-biphenol obtained, from which several fractions are then obtained by fractional crystallization. The third fraction with a melting point of 132–134 ° C can be identified as a product by comparing the melting point (133–134 ° C) given in the table on page 1066. This fraction has a weight of 4 g, so that this process gives a yield of only 2.7% pure product. According to his own investigations, according to US 6,171,996 carried out analogous reaction 2,3,5-trimethyl-phenol to 2,2'-dihydroxy-3,3 ', 4,4', 6,6'-hexamethyl-biphenyl no higher yield.

J. Chem. Soc. Perkin Trans. II (1983) 581-585 describes on page 585, right column, and page 583, right column, the production of 2,2'-dihydroxy-3,3 ', 4,4', 6,6'-hexamethyl-biphenyl by oxidative Coupling of two parts of 2,3,5-trimethylphenol using di-tert-butyl peroxide, whereby the starting material is presented as a melt at 140 ° C; the peroxide was according to the on Page 584 for the implementation of 2,3-dimethyl-phenol described method using only a fifth of that for quantitative sales required amount of peroxide added at the start of the reaction, so that only partial sales were achieved.

Tetrahedron 57 (2001) 331-343 on page 332 and 340, table and point 4.1. the oxidative coupling from 2-methoxy-3- (tert-butyl) -5-methylphenol to 2,2'-dihydroxy-3,3'-di-methoxy-4,4'-di- (tert-butyl) -6, 6'-di-methyl-biphenyl with di-tert-butyl peroxide in chlorobenzene as a liquid Diluents, the peroxide at the beginning of the reaction in one for one quantitative phenol sales sufficient amount is added. However, only small amounts of peroxide were used. The Adding large amounts of peroxides is out on an industrial scale security undesirable. Because it is generally known that peroxides tend to explode, for example from: Organikum, 2nd reprint of the 15th edition, VEB German Publishing House of Sciences, Berlin, 1981, p. 217.

The present invention was the Task based on a process for the preparation of 2,2'-dihydroxy-biphenyl by oxidative coupling of 2 phenol molecules in an o-position have a hydrogen atom by means of a peroxide, that this conversion with high yield and high educt conversions technically simple, economical and safe way.

Accordingly, the above was defined Process found.

Phenols in an o position having a hydrogen atom are generally known and commercial available.

Making one of the preferred Starting compounds 2,3,5-trimethylphenol is known and the compound commercially available, as for example from J. Chem. Soc. Perkin Trans. II (1983) 584, right column known.

In a further preferred embodiment As a phenol which has a hydrogen atom in an o position, Use phenol (hydroxybenzene).

In a further preferred embodiment, a 2-alkylphenol, preferably a C ₁ -C ₄ -alkylphenol, such as 2-methylphenol, 2-ethylphenol, 2-n-propylphenol, 2-i -Propyl-phenol, 2-n-butyl-phenol, 2-t-butyl-phenol, 2-i-butyl-phenol, especially 2-methyl-phenol or 2-t-butyl-phenol.

In a further preferred embodiment, a 2,4-dialkylphenol, preferably of the type 2-R1-4-R2-phenol, in which R1, R2 independently of one another are methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl or i-butyl, such as 2,4-dimethylphenol, 2-methyl-4-ethylphenol, 2-methyl-4-n-propylphenol, 2-methyl-4- i-propyl-phenol, 2-methyl-4-n-butyl-phenol, 2-methyl-4-t-butyl-phenol, 2-methyl-4-i-butyl-phenol, 2-ethyl-4-methyl- phenol, 2,4-diethylphenol, 2-ethyl-4-n-propylphenol, 2-ethyl-4-i-propylphenol, 2-ethyl-4-n-butylphenol, 2-ethyl- 4-t-butyl-phenol, 2-ethyl-4-i-butyl-phenol, 2-n-propyl-4-methyl-phenol, 2-n-propyl-4-ethyl-phenol, 2,4-di- n-propyl-phenol, 2-n-propyl-4-i-propyl-phenol, 2-n-propyl-4-n-butyl-phenol, 2-n-propyl-4-t-butyl-phenol, 2-n-propyl-4-i-butyl-phenol, 2-i-propyl-4-methyl-phenol, 2-i-propyl-4-ethyl- phenol, 2-i-propyl-4-n-propyl-phenol, 2,4-di-i-propyl-phenol, 2-i-propyl-4-n-butyl-phenol, 2-i-propyl-4- t-butyl-phenol, 2-i-propyl-4-i-butyl-phenol, 2-n-butyl-4-methyl-phenol, 2-n-butyl-4-ethyl-phenol, 2-n-butyl 4-n-propyl-phenol, 2-n-butyl-4-i-propyl-phenol, 2,4-di-n-butyl-phenol, 2-n-butyl-4-t-butyl-phenol, 2- n-butyl-4-i-butyl-phenol, 2-t-butyl-4-methyl-phenol, 2-t-butyl-4-ethyl-phenol, 2-t-butyl-4-n-propyl-phenol, 2-t-butyl-4-i-propyl-phenol, 2-t-butyl-4-n-butyl-phenol, 2,4-di-t-butyl-phenol, 2-t-butyl-4-i- butyl-phenol, 2-i-butyl-4-methyl-phenol, 2-i-butyl-4-ethyl-phenol, 2-i-butyl-4-n-propyl-phenol, 2-i-butyl-4- i-propyl-phenol, 2-i-butyl-4-n-butyl-phenol, 2-i-butyl-4-t-butyl-phenol, 2,4-di-i-butyl-phenol, in particular 2,4 -Di-methyl-phenol or 2,4-di-t-butyl-phenol, use.

In a further preferred embodiment a 2,5-dialkyl phenol, preferably of the type 2-R1-5-R2 phenol, can be used as the phenol, in the R1, R2 independently from each other methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl or i-butyl, such as 2,5-dimethylphenol, 2-methyl-5-ethyl-phenol, 2-methyl-5-n-propyl-phenol, 2-methyl-5-i-propyl-phenol, 2-methyl-5-n-butyl-phenol, 2-methyl-5-t-butylphenol, 2-methyl-5-i-butylphenol, 2-ethyl-5-methylphenol, 2,5-diethylphenol, 2-ethyl-5-n-propyl-phenol, 2-ethyl-5-i-propyl-phenol, 2-ethyl-5-n-butyl-phenol, 2-ethyl-5-t-butyl-phenol, 2-ethyl-5-i-butyl-phenol, 2-n-propyl-5-methyl-phenol, 2-n-propyl-5-ethyl-phenol, 2,5-di-n-propyl-phenol, 2-n-propyl-5-i-propyl-phenol, 2-n-propyl-5-n-butyl-phenol, 2-n-propyl-5-t-butyl-phenol, 2-n-propyl-5- i-butyl-phenol, 2-i-propyl-5-methyl-phenol, 2-i-propyl-5-ethyl-phenol, 2-i-propyl-5-n-propyl-phenol, 2,5-di-i-propyl-phenol, 2-i-propyl-5-n-butyl-phenol, 2-i-propyl-5-t-butyl-phenol, 2-i-propyl-5-i- butyl-phenol, 2-n-butyl-5-methyl-phenol, 2-n-butyl-5-ethyl-phenol, 2-n-butyl-5-n-propyl-phenol, 2-n-butyl-5-i-propyl-phenol, 2,5-di-n-butyl- phenol, 2-n-butyl-5-t-butyl-phenol, 2-n-butyl-5-i-butyl-phenol, 2-t-butyl-5-methyl-phenol, 2-t-butyl-5-ethyl-phenol, 2-t-butyl-5-n-propyl-phenol, 2-t-butyl-5-i-propyl-phenol, 2-t-butyl-5-n- butyl-phenol, 2,5-di-t-butyl-phenol, 2-t-butyl-5-i-butyl-phenol, 2-i-butyl-5-methyl-phenol, 2-i-butyl-5-ethyl-phenol, 2-i-butyl-5-n-propyl-phenol, 2-i-butyl-5-i-propyl-phenol, 2-i-butyl-5-n-butyl-phenol, 2-i-butyl-5-t-butyl-phenol, 2,5-di-i-butyl-phenol, in particular 2-isopropyl-5-methyl-phenol, deploy.

In a further preferred embodiment A 3,5-dialkyl phenol, preferably of the 3-R1-5-R2 phenol type, can be used as the phenol, in the R1, R2 independently from each other methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl or i-butyl, such as 3,5-dimethylphenol, 2-methyl-5-ethyl-phenol, 3-methyl-5-n-propyl-phenol, 3-methyl-5-i-propyl-phenol, 3-methyl-5-n-butyl-phenol, 3-methyl-5-t-butylphenol, 3-methyl-5-i-butylphenol, 3-ethyl-5-methylphenol, 3,5-diethylphenol, 3-ethyl-5-n-propyl-phenol, 3-ethyl-5-i-propyl-phenol, 3-ethyl-5-n-butyl-phenol, 3-ethyl-5-t-butyl-phenol, 3-ethyl-5-i-butyl-phenol, 3-n-propyl-5-methyl-phenol, 3-n-propyl-5-ethyl-phenol, 3,5-di-n-propyl-phenol, 3-n-propyl-5-i-propyl-phenol, 3-n-propyl-5-n-butyl-phenol, 3-n-propyl-5-t-butyl-phenol, 3-n-propyl-5- i-butyl-phenol, 3-i-propyl-5-methyl-phenol, 3-i-propyl-5-ethyl-phenol, 3-i-propyl-5-n-propyl-phenol, 3,5-di-i-propyl-phenol, 3-i-propyl-5-n-butyl-phenol, 3-i-propyl-5-t-butyl-phenol, 3-i-propyl-5-i- butyl-phenol, 3-n-butyl-5-methyl-phenol, 3-n-butyl-5-ethyl-phenol, 3-n-butyl-5-n-propyl-phenol, 3-n-butyl-5-i-propyl-phenol, 3,5-di-n-butyl- phenol, 3-n-butyl-5-t-butyl-phenol, 3-n-butyl-5-i-butyl-phenol, 3-t-butyl-5-methyl-phenol, 3-t-butyl-5-ethyl-phenol, 3-t-butyl-5-n-propyl-phenol, 3-t-butyl-5-i-propyl-phenol, 3-t-butyl-5-n- butyl-phenol, 3,5-di-t-butyl-phenol, 3-t-butyl-5-i-butyl-phenol, 3-i-butyl-5-methyl-phenol, 3-i-butyl-5-ethyl-phenol, 3-i-butyl-5-n-propyl-phenol, 3-i-butyl-5-i-propyl-phenol, 3-i-butyl-5-n-butyl-phenol, 3-i-butyl-5-t-butylphenol, 3,5-di-i-butylphenol, in particular 3,5-dimethylphenol or 3,5-di-t-butyl-phenol.

In a further preferred embodiment a 2,3,5-trialkyl phenol, preferably of the type 2-R1-3-R2-5-R3-phenol, can be used as the phenol, in the R1, R2, R3 independently from each other methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl or i-butyl, in particular 2,3,5-trimethylphenol, use.

Mixtures of Phenols, especially the phenols mentioned, can be used.

The use is only advantageous of a phenol.

According to the invention, the implementation is carried out at a Temperature in the range of 140 to 180 ° C.

In an advantageous embodiment temperatures come at most 170 ° C, especially at most 160 ° C, in Consideration.

In an advantageous embodiment temperatures of at least 145 ° C, in particular at least 150 ° C, come into consideration.

According to the invention, the coupling reaction is carried out by means of a peroxide.

As a peroxide one can be advantageous a compound of the formula formula (tert-butyl) -O-O-R with R = H, tert-butyl or mixtures thereof, especially di-tert-butyl peroxide.

Process for the production of such Peroxides are known per se and the peroxides are commercially available.

To achieve high sales is theoretically the addition of 0.5 mol for the coupling reactive peroxide units required per mole of phenol. The addition of an amount of 0.5 to 1.2 mol, in particular 0.6 to 0.8 mol, of peroxide units reactive for the coupling per mole of phenol has proven to be advantageous.

According to the invention, the peroxide is added to the reaction mixture continuously. Under such a continuous feed means for the purposes of the present invention, the addition of the peroxide to the reaction mixture within a period of at least 5 hours, preferably at least 7 hours, especially 8 hours, wherein times of at most 24 hours, preferably at most 20 hours, especially at most 16 hours have been shown to be preferred, evenly or in at least two Partial streams, as by dropping, the addition, like dropping, unevenly, preferably done evenly can.

The inventive method can in one preferred embodiment in the absence of a liquid diluent carried out become.

The inventive method can in one preferred embodiment in the presence of an inorganic, preferably organic, liquid diluent carried out become.

Aromatics come as liquid diluents, advantageously partially or completely halogenated aromatics, such as chlorobenzene, o-dichlorobenzene, m-dichlorobenzene, p-dichlorobenzene, alkanes, such as decane, undecane, dodecane, partially or fully halogenated Alkanes or alkanes bearing nitrile groups into consideration.

Preferred liquid diluents are o-dichlorobenzene, m-dichlorobenzene, p-dichlorobenzene, or mixtures thereof, particularly preferably o-dichlorobenzene, p-dichlorobenzene or mixtures thereof, in particular o-dichlorobenzene.

Also preferred as a liquid diluent Alkanes or mixtures of alkanes, preferably those with a Boiling point or boiling range above the intended reaction temperature, particularly preferably above 180 ° C., in particular in the range from 180 ° C to 250 ° C, especially preferably in the range from 180 to 220 ° C.

The amount of liquid diluent, based on phenol, is not critical in itself. There have been amounts of at least 0.5 g of diluent per g of phenol proved advantageous. Furthermore, quantities of at the most 2 g of diluent per g of phenol proved to be advantageous.

The method according to the invention can in itself for such Reactions known devices are carried out, such as kettles or Glass flask, these apparatuses advantageous devices for forced movement of the reaction mixture should have, such as stirring elements. If you expose containers Metal comes in, one comes in advantageously for safety reasons Coating the metal surface facing the reaction mixture with Email, glass or one opposite polymers inert to the reaction mixture.

If you use a peroxide, that one Has a boiling point below the stated minimum temperature of the reaction mixture, such as di-tert-butyl peroxide, the apparatus can also be advantageous above the reaction mixture, for example at the top of the apparatus, a cooling device, like a top cooler.

In a preferred embodiment can this cooler are operated in such a way that by-products formed during the reaction, like t-butanol, while the reaction, preferably continuously, are distilled off.

The choice of the reaction temperature and the rate of addition of the peroxide can advantageously be set in this way that the concentration of peroxide in the reaction mixture while of the whole process remains small and arises during the reaction By-products can be distilled off so that the reaction temperature remains constant. The one for this optimal parameters can be easily determined by a few simple preliminary tests determine.

After implementation, the product can from the reaction mixture by methods known per se, such as extraction, Distillation or crystallization can be obtained. One leads the reaction in the presence of a liquid diluent advantageously one in which the product, the starting material, the peroxide and any by-products formed in the above for the Implementation called temperature range high solubility have while at temperatures below this range the solubility of the product is faster decreases as the solubility of the educts and other products. In this case, the product after the reaction by cooling the reaction mixture to technically simple and economical Crystallized from the mixture in a high purity and yield become.

A particularly suitable liquid diluent for this represents o-dichlorobenzene, m-dichlorobenzene, p-dichlorobenzene, or their Mixtures, particularly preferably o-dichlorobenzene, p-dichlorobenzene or mixtures thereof, especially o-dichlorobenzene represents.

In a preferred embodiment come as a liquid thinner Alkanes or mixtures of alkanes, preferably those with a Boiling point or boiling range above the intended reaction temperature, particularly preferably above 180 ° C., in particular in the range from 180 ° C to 200 ° C.

Examples 1-6

The reaction was carried out in a 250 ml Four-necked flask containing a double-walled dropping funnel, a distillation head (Normag, Germany) with template and a thermometer and with a magnetic stirrer was equipped. While the implementation the reaction was over added argon to the top of the dropping funnel; the argon became that System over a valve taken from the templates. The argon flow was determined using of a floating flow meter and is constant during the reaction held.

25 g (0.184 mol) 2,3,5-trimethylphenol, 25 g of solvent according to the table 1 heated under argon to the reaction temperature according to Table 1. The stream of argon was adjusted to 2 l / h and 21.5 g (0.147 mol) di-tert-butyl peroxide within 8 hours using a pump (Metrohm Dosimat 665) added dropwise. While that time became fleeting Connections separated by distillation and collected in the template.

Then the reaction mixture stirred at the reaction temperature until gas chromatographic no more di-tert-butyl peroxide could be detected. The Yields determined by gas chromatography are shown in Table 1.

Then the reaction mixture slowly cooled to room temperature and stirred for a further 18 hours at this temperature. The unusual product was filtered, twice with 23.1 g of mother liquor and three times washed with 20 ml each of n-heptane and dried under vacuum.

The yields and purities after this crystallization and purification are shown in Table 1.

Tabelle 1

Table 1

Varsol 60: petroleum distillate (Alkane mixture) with a boiling range of 183-216 ° C

Example 7

The reaction was thermostated 2000 ml four-necked flask containing a double-walled dropping funnel a distillation head (company Normag, Germany) with template, carried a thermometer and a mechanical stirrer. During the execution the reaction was over added the head of the dropping funnel argon (2 l / h); that became argon the system a valve taken from the templates. The argon flow was determined using of a floating flow meter and is constant during the reaction held.

408 g (2.97 mol) 2,3,5-trimethylphenol, 408 g of Varsol 60 heated to 155 ° C. under argon. Then 350 g (2.40 mol) of di-tert-butyl peroxide within Dropwise for 12 hours using a pump (Metrohm Dosimat 665) added. While that time became fleeting Connections separated by distillation and collected in the template.

Then the reaction mixture stirred at the reaction temperature until gas chromatographic no more di-tert-butyl peroxide could be detected. Then the reaction mixture was slowly cooled to room temperature and stirred at this temperature for a further 18 hours. The unusual product 3,3 ', 4,4', 6,6'-hexamethyl-1,1'-dihydroxy-biphenyl was filtered off, washed three times with 100 ml of n-heptane and dried under vacuum.

The yield of 3,3 ', 4,4', 6,6'-hexamethyl-1,1'-dihydroxy-biphenyl was 61% (245 g).

Addition of the peroxide in the present coupling reaction according to the prior art, that is to say addition of the entire amount at the beginning of the reaction, leads to problems at the present high reaction temperatures because of the thermal decomposition of the peroxides with the formation of undesired by-products and at the same time in the case of peroxides whose boiling point is significantly below the reaction temperature, problems with the setting and maintenance of this high reaction temperature. Working at low temperatures would suppress the self-decomposition of the peroxide, but would also lead to a significant decrease in the reaction rate.

Furthermore, heating large quantities of di-tert-butyl peroxide according to the prior art the technology, such as continuously added in example 7, very dangerous.

So the present procedure leads despite a slower addition of the peroxide to an overall higher reaction rate as a procedure according to technology with a significantly reduced security risk.

Claims (12)

A process for the preparation of a 2,2'-dihydroxy-biphenyl by oxidative coupling of two phenol molecules which have a hydrogen atom in an o-position, using a peroxide, characterized in that the reaction is carried out at a temperature in the range from 140 to 180 ° C is carried out and the peroxide is fed continuously to the reaction mixture. The method of claim 1, wherein the reaction resulting by-products during distilled off the reaction. The method of claim 1 or 2, wherein the reaction in the absence of a liquid diluent performs. The method of claim 1 or 2, wherein the reaction in the presence of a liquid diluent performs. A method according to claim 4, wherein as a liquid diluent o-, m- or p-dichlorobenzene or uses their mixtures. A method according to claim 4, wherein as a liquid diluent an alkane or a mixture of alkanes with a boiling point in the range from 180 to 250 ° C starts. Process according to claims 1 to 6, wherein as Peroxide a compound of the formula (tert-butyl) -O-O-R with R = H, uses tert-butyl or mixtures thereof. Process according to claims 1 to 6, wherein as Peroxide di-tert-butyl peroxide starts. Process according to claims 1 to 8, wherein as Phenol 2,3,5-trimethylphenol used to obtain 2,2'-dihydroxy-3,3 ', 4,4', 6,6'-hexamethyl-biphenyl. Process according to claims 1 to 8, wherein one Phenol from the group consisting of phenol, 2-R1-phenol, 2-R1-4-R2-phenol, 2-R1-5-R2-phenol, 3-R1-5-R2-phenol or mixtures of such phenols, where R1, R2 independent from each other methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl or t-butyl. Process according to claims 1 to 8, wherein as Phenol 2-isopropyl-5-methylphenol used to obtain 2,2'-dihydroxy-3,3'-diisopropyl-6,6'-dimethyl-biphenyl. Process according to claims 1 to 8, wherein as Phenol 2,4-di-tert-butylphenol used to obtain 2,2'-dihydroxy-3,3 ', 5,5'-tetra-tert-butyl-biphenyl.