AU701242B2

AU701242B2 - Process for preparing 2,2'-bis(diphenylphosphinylmethyl) -1,1'-binaphthyls and new compounds from this class of substances

Info

Publication number: AU701242B2
Application number: AU14849/95A
Authority: AU
Inventors: Hans-Jerg Kleiner; Dieter Regnat; Horst Roschert
Original assignee: Hoechst AG
Current assignee: Celanese Sales Germany GmbH
Priority date: 1994-03-23
Filing date: 1995-03-15
Publication date: 1999-01-21
Anticipated expiration: 2015-03-15
Also published as: JPH0841086A; ES2161791T3; AU1484995A; EP0673944A1; JP3761213B2; CA2145255A1; EP0673944B1; ATE204284T1

Abstract

Prodn. of 2,2'-bis(diphenylphosphinylmethyl)-1,1'-binaphthyls (I) comprises: (a) reacting 2,2'-dimethyl-1,1'-binaphthyl (II) with a brominating agent in a solvent to form 2,2'-bis(bromomethyl)-1,1'-binaphthyl (III) and other brominated binaphthyls; (b) opt. removing unreacted brominating agent, reacted brominating agent and/or solvent; and (c) reacting the prod. with an alkyl diphenylphosphinite of formula RO-P(Ar)2 (IV) at 70-180 degrees C, opt. in a solvent; where = R = 1-5C alkyl; and Ar = phenyl opt. mono- or disubstd. by 1-4C alkyl, CF3, F, Cl or Br. Also claimed are cpds. of formula (IA): Ar' = phenyl mono- or disubstd. by 1-4C alkyl, CF3, F, Cl or Br. Step (a) comprises reacting (II) with N-bromosuccinimide (NBS) in chlorobenzene and/or dichlorobenzene, either at -10 to +75 (esp. 0-40) degrees C in the presence of light with a wavelength of 10-10,000 nm, or at 25-150 (esp. 40-135) degrees C in the presence of a free radical source. Step (c) is effected at 100-170 (esp. 120-160) degrees C, opt. after replacing the (di)chlorobenzene with xylene and/or mesitylene.

Description

Our Ref: 544281 P/00/011 Regulation 3:2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT o coo eo *oo o• 0 o ooeoo Applicant(s): Hoechst Aktiengesellschaft D-65926 FRANKFURT AM MAIN

GERMANY

Address for Service: Invention Title: DAVIES COLLISON CAVE Patent Trade Mark Attorneys Level 10, 10 Barrack Street SYDNEY NSW 2000 Process for preparing 2,2'-bis(diphenylphosphinylmethyl) -1,l'-binaphthyls and new compounds from this class of substances The following statement is a full description of this invention, including the best method of performing it known to me:- 5020 1 Description Process for preparing 2,2'-bis (diphenylphosphinylmethyl) l,l'-binaphthyls and new compounds from this class of substances.

The present invention relates to an improved process for preparing 2,2'-bis(diphenylphosphinylmethyl)-1,1'-binaphthyls and also new compounds from this class of substances.

2,2'-Bis(diphenylphosphinylmethyl)-1,1'-binaphthyl (formula I) is an important precursor for the preparation of 2,2'-bis(diphenylphosphinomethyl)-1,1'-binaphthyl (formula II), a bidentate phosphine (phosphane) which is used as a ligand for catalysts, for example in the coupling of haioaromatics catalyzed by metal complexes.

0 SPPh 2

P

PPh 2 PPh 2 P*h eee 15 2,2'-Bis(diphenylphosphinylmethyl)-1,1'-binaphthylcanbe prepared in the following manner. The starting material is the corresponding aromatic methyl compound, namely 2,2'-dimethyl-1,1'-binaphthyl, and the methyl group is brominated using N-bromosuccinimide to give 2,2'-bis- (bromomethyl)-1,1'-binaphthyl (formula III). In this reaction, which is described a number of times in the literature and is carried out in the presence of a freeradical former but without the action of light, tetrachloromethane is generally used as solvent E. Jung et al., Tetrahedron Lett. 29 (1988) 6199; H. J. Bestmann et al., Chem. Ber. 107 (1974) 2926; Mazaleyrat, Chem.

Commun. 1985, 317; T. Hayashi et al., J. Am. Chem. Soc.

110 (1988) 8153).

I

2 Owing to the comparatively low boiling point of tetrachloromethane, namely 76.5 0 C, a reaction at higher temperatures can only be carried out under pressure, which requires additional technical complication.

Furthermore, the yield of 2,2'-bis(bromomethyl)-l,l'binaphthyl achievable by this process is, at about 60 not very high.

The bromination of 2,2'-dimethyl-1,1'-binaphthyl gives, besides the desired product (formula III) essentially two byproducts, presumably 2-bromomethyl-2'-methyl-l,l'binaphthyl and 2-dibromomethyl-2'-bromomethyl-l,1'binaphthyl.

Although the isolation of 2,2'-bis(bromomethyl)-1,1'binaphthyl in pure form can be successfully carried out 15 by crystallization or by column chromatography, this is at the cost of, on the one hand, considerable yield losses or, in the case of column chromatography, very high technical complication.

ee o oo oe o oo **o oo* o•

A'

'7 Or European Patent Application No. 0 595 150 (93116788.6) describes the preparation of 2,2'-bis(bromomethyl)-1,1'binaphthyl by reaction of 2,2'-dimethyl-l,1'-binaphthyl with N-bromosuccinimide in the presence of benzoyl peroxide, but without the action of light, in chlorobenzene. After the reaction is complete, the solvent is evaporated, the residue is taken up in ethyl acetate and washed first with 10 strength Na 2

SO

3 solution then with saturated Na 2 C0 3 solution and finally with saturated NaCl solution. After drying and recrystallization, this gives a yield of 65 However, this process proves to be complicated (evaporation of the solvent, transfer of the residue into another solvent and washing three times with an aqueous sodium salt solution each time), in addition the yield also leaves something to be desired.

N

i) II, b PI ~r 1~81PY_ ~ILL Ibl I 3 The bromination of 2,2'-dimethyl-1,1'-binaphthyl generally leads to a product mixture which is problematical to handle. It has thus been found that the removal of the solvent, even when carried out under gentle conditions (vacuum), leads to a mixture which is thermally unstable and begins to decompose exothermically above a temperature of only 50 0

C.

It is known from Houben-Weyl, Methoden der organischen Chemie, volume V/4, pages 333 and 334, that aralkyl bromides in the pure state are colorless substances usually having little thermal stability and some of them cannot be distilled without decomposition, even in vacuo.

Naphthylmethyl bromides are generally less stable then benzyl bromides.

For this reason, the isolation of the crude product formed in the bromination is encumbered by a considerable hazard potential which, in particular for the large amounts of starting materials or raw materials handled on an industrial scale, poses an unpredictable risk.

:i.

Br naphthyl (formula pure 2,2'-bis(bromomethyl) -1,1'-binaphthyl, i.e. not a mixture of various brominated binaphthyls, can be subjected to the Arbusov reaction with methyl diphenylphosphinite (formula V, where R is ,0 RO-P(Ph-( (Iv) •ith 0 TOpeare 2,2'-bi(iphnlphopinlmethyl)-lr'-bi-

CH

3 and n is 0) without addition of a solvent. As described in JP 7 939 059 or CA 91,91764 v, the two abovementioned components are heated in a ratio of 1:6.7 for three hours at 130 0 C to give the desired product (formula The reaction is, however, problematical, "V U-U- 4since, as can be seen from Experiment 4 of JP 7 939 059, an explosive reaction occurs at 87 0 C. The yield achieved is only 30 The process is not suitable for an industrial process, neither with regard to the required process safety nor with regard to the yield.

There is therefore a need to develop a process for preparing 2,2'-bis (diphenylphosphinylmethyl)-1,1' -binaphthyls which does not have the abovementioned disadvantages, can also be carried out simply and reliably and enables the desired product to be obtained in high yield and purity.

This object is achieved by a process for preparing 2,2'bis(diphenylphosphinylmethyl)-1,1'-binaphthyls. It comprises reacting a reaction mixture prepared in a solvent by reaction of 2,2'-dimethyl-1,1'-binaphthyl with a brominating agent and containing 2,2'-bis(bromomethyl)l,l'-binaphthyl and further brominated binaphthyls, if desired after removal of unreacted brominating agent, reacted brominating agent and/or solvent, with an alkyl 20 diphenylphosphinite of the formula (IV) RO-P(Ph-(R')n) 2 where R is an alkyl radical having from 1 to 5, in particular from 1 to 3, carbon atoms, Ph is phenyl, R' is an alkyl radical having from 1 to 4 carbon atoms, CF 3 fluorine, chlorine or bromine, in particular methyl, CF 3 or fluorine, and n is 0, 1 or 2, at from 70 to 180 0 C in the presence or absence of a further solvent.

An advantage of the process of the invention is that in the preparation of the reaction mixture, isolation of the 2,2'-bis(bromomethyl)-l,l'-binaphthyl (formula III) is 30 omitted and in this way a quite complicated separation operation, which owing to the thermal instability of the reaction product formed in the bromination also presents a safety risk, is avoided. Furthermore, with suitable selection of the solvent, the solvent used in the reaction can remain in the reaction mixture. It does not have to be removed from the reaction mixture.

-fi -I- NjWI A f# 01 4 5 However, it is also possible to replace, if required, the solvent originally used in the bromination step by a further solvent and to completely or partially distil off the solvent originally used. In this way, although the solvent originally used is replaced by the further solvent, a quite complicated separation operation (isolation of the 2,2'-bis(bromomethyl)-l,l'-binaphthyl) can nevertheless be avoided.

The reaction mixture contains, independently of the method of bromination, the brominated compounds usually formed in a bromination, namely, besides the desired product, essentially presumably the two abovementioned brominated byproducts and also the solvent. The reaction mixture generally obtained contains from 60 to 85 mol in particular from 65 to 83 mol of 2,2'-bis(bromomethyl)-l,l'-binaphthyl and from 40 to 15 mol in particular from 35 to 17 mol of further brominated binaphthyls, with the solvent still present not being taken into account.

20 The one byproduct, presumably 2-bromomethyl-2'-methyll,l'-binaphthyl, makes up from 1 to 20 mol in particular from 3 to 18 mol and the other byproduct, presumably 2-dibromomethyl-2' -bromomethyl-1,1' -binaphthyl makes up from 3 to 20 mol in particular from 5 to 17 mol The method of bromination also influences to a certain extent both the amount of the brominated binaphthyls formed and also the ratio in which the two abovementioned byproducts are formed.

In general, the amount of solvent used is of no great 30 importance. However, a sufficient amount should be used.

In general it is sufficient to use 2,2'-dimethyl-l,1'binapthyl and the solvent in a weight ratio of 1:(3 to in particular 1:(4 to 20), preferably 1:(5 to Solvents which can be used are generally those which are inert under the reaction conditions of the bromination.

YIII~B~C~LP6 i~ I'Y~rZ~I I l\l~i~f~~1TS~-VUI~71U;i~ ~CII 6 Use can be made of monochlorinated or polychlorinated benzene, a monochlorinated or polychlorinated aliphatic hydrocarbon, an ester of an aliphatic carboxylic acid having from 1 to 6 carbon atoms and an alkyl alcohol having from 1 to 4 carbon atoms or mixtures thereof as solvents. Examples of such solvents are chloroform, dichloromethane, tetrachloromethane, chlorobenzene, ortho-, meta- and para-dichlorobenzene, methyl formate, ethyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate and propyl propionate. Well-suited solvents are chlorobenzene or dichlorobenzene or any mixture of these solvents. Chlorobenzene is particularly useful.

In some cases, esters of the abovementioned type, in particular methyl and ethyl esters of aliphatic carboxylic acids having from 1 to 3 carbon atoms, can also be used with good results.

In the preparation of the reaction mixture, the bromination can be carried out under the action of light having 20 a wavelength of from 10 5 to 10-8 m, in particular from 10 6 to 2x10 7 It is here usual to allow the reaction of 2,2'-dimethyl-l,l'-binaphthyl to proceed at from -10 to 75 0 C. In many cases, it is found to be sufficient to react 2,2'-dimethyl-l,1'-binaphthyl with the brominating agent at from -5 to 50 0 C, in particular from 0 to 40 0

C.

The light source used for the bromination can be a conventional UV irradiator, for example a daylight lamp, a doped or undoped mercury vapor lamp or low-pressure mercury vapor lamp. On the other hand, 2,2'-dimethyl- 30 l,l'-binaphthyl and the brominating agent can be reacted in the absence of light, but in the presence of a freeradical former at from 25 to 150 0 C, in ,-rticular from to 135 0

C.

The bromination can be carried out using a customary brominating agent, for example bromine, c, 7 N-bromosuccinimide, 1,3-dibromo-5,5-dimethylhydantoin, brominated Meldrum's acid.

It has been found to be favorable to react 2,2'-dimethyl- 1,l'-binaphthyl with N-bromosuccinimide as brominating agent. 2,2'-Dimethyl-1,1'-binaphthyl and N-bromosuccinimide are usually used in a molar ratio of 1:(1.5 to in particular 1:(1.8 to preferably 1:(1.9 to 2.2).

In the course of the bromination, N-bromosuccinimide forms succinimide which, if desired after cooling the solution containing the reaction product, is removed by filtration. A further possibility is to remove the succinimide formed by extraction with water. For this purpose, from 10 to 100% by weight of water, based on reaction mixture, are usually used.

A particularly simple and at the same time effective method of removing succinimide is to separate the succinimide formed from the reaction mixture in a first step by filtration and in a second step by extraction with water. This uses comparatively little water and accordingly also gives little wastewater.

The bromination carried out under the action of light gives the desired product in a yield of about 80 In addition, it usually gives from 1 to 6 of a brominated .substance, presumably 2-bromomethyl-2'-methyl-l,1'- 25 binaphthyl, and from 7 to 13 of a further byproduct, presumably 2-dibromomethyl-2'-bromomethyl-l,l'binaphthyl.

The corresponding reaction mixture used in the Arbusov reaction presumably contains, besides small 30 amounts of substances not identified in more detail, the abovementioned bromo compounds dissolved in the solvent, for example in chlorobenzene and/or dichlorobenzene, in particular in chlorobenzene.

In place of the reaction mixture prepared under the I sq *u*a 8 action of light, it is also possible to use a reaction mixture which can be obtained, for example, by reaction of 2,2'-dimethyl-1,l'-binaphthyl with N-bromosuccinimide in the presence of a solvent under the action of a free-radical former (free-radical initiator) and by subsequent removal of succinimide, with good results in the Arbusov reaction (reaction with the alkyl diphenylphosphinite). Such a reaction mixture can be prepared by reacting 2,2'-dimethyl-l,l'-binaphthyl with N-bromosuccinimide, for example in a molar ratio of 1:(1.5 to in particular 1:(1.8 to preferably 1:(1.9 to at elevated temperature, usually at temperatures of from 25 to 150 0 C, in particular from 40 to 135 0 C, under the action of a free-radical initiator in chlorobenzene and/or dichlorobenzene, removing succinimide formed, but without removing the chlorobenzene and/or dichlorobenzene used as solvent.

Suitable free-radical initiators are the customary freeradical formers, for example organic peroxides, hydroperoxides, azobisisobutyronitrile.

The bromination carried out under the action of the freeradical initiator gives the desired product in a yield of from about 63 to 67 In addition, it generally gives s from 10 to 20 of a brominated product, presumably 25 2-bromomethyl-2'-methyl-1,1'-binaphthyl, and from 8 to of a further byproduct, presumably 2-dibromomethyl- 2-bromomethyl-l,1'-binaphthyl. The reaction mixture (B) used in the Arbusov reaction presumably contains, besides small amounts of substances not identified in more 30 detail, the abovementioned bromo compounds dissolved in chlorobenzene and/or dichlorobenzene, in particular chlorobenzene.

The succinimide formed from the N-bromosuccinimide is separated from the bromination mixture, if desired after cooling, by filtration. Another possibility is to carry out the subsequent removal of succinimide by extraction with water.

s, LILILI 9- A particularly simple and effect .e variant is to separate succinimide from the bromination mixture in a first step by filtration and in a second step by extraction with water.

Unreacted free-radical formers can be removed, for example, by scrubbing with an aqueous Na 2

SO

3 solution.

The abovedescribed procedure gives the reaction mixture To carry out the Arbusov reaction, the reaction mixture, for example the reaction mixture or the reaction mixture is reacted with an alkyl diphenylphosphinite (formula IV), as already mentioned above, at from 70 to 180 0 C. In many cases, it is sufficient to carry out the reaction at from 100 to 170 0 C, in particular from 120 to 160 0 C. The reaction proceeds according to the following equation: o Br 2 Ir 2 R0-F(Ph-(R').)2 H i I "f

II

(III) (Iv) (lo) at The alkyldiphenylphosphinite of the formula (IV) used is usually a (C 1

-C

5 )alkyl diphenylphosphinite or a mixture of these esters. Suitable alkyl diphenylphosphinites are, without claiming completeness, methyl diphenylphosphinite, ethyl diphenylphosphinite, isopropyl diphenylphosphinite, n-propyl diphenylp osphinite, ethyl bis(3fluorophenyl)phosphinite, ethyl bis(4-fluorophenyl)phosphinite, ethyl bis(2-methylphenyl)phosphinite and/or ethyl bis(3-trifluoromethylphenyl)phosphinite.

The alkyl diphenylphosphinite is generally used in a I Ilr C 10 molar ratio of (1.8 to in particular (1.9 to 3):1, preferably (2 to based on the 2,2'-dimethyl-1,1'binaphthyl. However, in many cases it is possible to use the alkyl diphenylphosphinite (formula IV), based on 2,2'-dimethyl-1,l'-1inaphthyl used, in the stoichiometric ratio or in a slight excess.

Before the reaction mixture resulting from the bromination stage is used in the subsequent Arbusov react .0- (reaction with the alkyl diphenylphosphinite), it is advisable, as mentioned above, in many cases to remove the unreacted brominating agent and/or the reacted brominating agent and/or the solvent used in the bromination stage.

Unreacted brominating agent, for example bromine, can be removed by vaporization, reacted brominating agent, for example succinimide, can be removed by filtration and extraction. The solvent used in the bromination stage is replaced by a further solvent which has a boiling point higher than that of the solvent originally used. The further solvent is added prior to the reaction or during the reaction after the reaction of the reaction mixture with the alkyl diphenylphosphinite and the solvent originally used is subsequently distilled off.

This removal of the original solvent can be carried out 25 prior to the Arbusov reaction or even during the Arbusov reaction or after the Arbusov reaction. If a solvent which is inert to the Arbusov reaction is used as original solvent, it can be removed during the Arbusov reaction or the removal can even be omitted. Such sol- 30 vents are, for example, chlorobenzene, dichlorobenzene and mixtures thereof; when they are used a removal is not absolutely necessary.

Solvents which are not inert to the Arbusov reaction have to be removed prior to carrying out the Arbusov reaction.

Such solvents are, for example, monochlorinated or polychlorinated aliphatic hydrocarbons.

Suitable further solvents are generally solvents which have a boiling point higher than that of the solvent L -L-1 11 originally used and which are inert under the conditions of the Arbusov reaction. These include aromatic hydrocarbons, for example toluene, o-xylene, m-xylene, p-xylene, mixtures of these xylenes, eth-lbenzene and/or mesitylene and high-boiling aliphatic hydrocarbons, for example petroleum ether having a boiling point 100 0 C, decalin, ligroin and/or isooctane.

The Arbusov reaction can thus be carried out in the presence or absence of a further solvent.

In some cases it has been found to be advantageous to add the further, nonpolar solvent which has a boiling point higher than that of the solvent originally used during the Arbusov reaction (reaction with the alkyl diphenylphosphinite) and to simultaneously distill off the solvent originally used, for example chlorobenzene and/or dichlorobenzene. Suitable solvents for this purpose are, for example, aromatic compounds having boiling points higher than chlorobenzene and/or dichlorobenzene, for example o-xylene, m-xylene, p-xylene, mixtures of these xylenes and/or mesitylene. This allows the yield of 2,2'bis(diphenylphosphinylmethyl) -binaphthyl isolated to be increased somewhat further.

It is surprising that the brominated binaphthyls, for example the brominated byproducts present in both the reaction mixture and in the reaction mixture (B) generally do not interfere in the Arbusov reaction and also do not impair the quality of the desired final product (formula Furthermore, it is unexpected that S" the use of a solvent, for example the use of chlorobenzene and/or dichlorobenzene, in the Arbusov reaction leads to a significant increase in yield. While the process of JP 7 939 359 gives a yield of only 30 the process of the invention gives a yield of from 90 to 95 of desired product, in each case based on 2,2'-bis(bromomethyl)-1,l'-binaphthyl. In addition, the danger of the reaction occurring explosively is avoided.

_I I 1, I- 12 To carry out the Arbusov reaction, the reaction mixture, for example reaction mixture or the reaction or mixtures of the two reaction mixtures, is usually initially charged and heated to the prescribed temperature. It is advantageous to select a temperature below the boiling point of the solvent used. After reaching the reaction temperature, the alkyl diphenylphosphinite is slowly added dropwise to the initially charged reaction solution. As the reaction proceeds, it results in the formation of alkyl bromide which is continuously distilled from the reaction product. If desired, the mixture can also be boiled under reflux for some time after the end of the addition of the alkyl diphenylphosphinite, so as to complete the reaction.

If it is intended that the solvent originally used be removed during the Arbusov reaction, a temperature above the boiling point of the original solvent but below that of the further solvent added is selected. In this way, both the alkyl bromide and also the solvent originally used distills off.

«o The process of the invention makes it possible to obtain the new compounds of the formula (Ia) 0 W) so* o where R is an alky radical having from to 4 carbon atoms, CF 3 fluorine, chlorine or bromine, in particular methyl, CF 3 or fluorine, and n is 1 or 2, in a surprisingly simple manner by reaction of 2,2'-bis(bromomethyl)-1, 1' -binaphthyl of the formula (III) with the corresponding diphenylphosphinic ester of the formula IV.

l corresponding diphenylphosphinic ester of the formula IV.

I

13 New compounds in this category which may be mentioned are, in particular, 2,2'-bis[bis(3-fluorophenyl)phosphinylmethyl]-1,1'binaphthyl, 2,2'-bis[bis(4-fluorophenyl)phosphinylmethyl]-1,1'binaphthyl, 2,2'-bis[bis(2-methylphenyl)phosphinylmethyl]-1,1'binaphthyl and 2,2'-bis[bis(3-trifluoromethylphenyl)phosphinylmethyl]- 1,l'-binaphthyl.

The following examples illustrate the invention without limiting it.

Experimental part: Example 1 Preparation using a reaction mixture A With exclusion of moisture, 282.4 g (1.0 mol) of dimethyl-1,1'-binaphthyl and 373.8 g (2.1 mol) of N-bromosuccinimide are suspended in 1.7 1 of chlorobenzene in a 4 1 glass flask and are illuminated with a 20 UV immersion lamp for 8 hours at from 5 to 10°C. The precipitated succinimide filtered off, the solution is extracted twice with 200 ml of water each time, dried using sodium sulfate and filtered. The filtrate (reaction mixture A) is transferred to a 4 1 four-neck flask fitted with stirrer, dropping funnel, reflux condenser and internal thermometer and is heated to 125 0 C. 460.5 g mol) of ethyl diphenylphosphinite are then slowly added dropwise, with ethyl bromide distilling off. After the end of the addition, the mixture is heated under reflux for a further two hours and is then cooled to 0°C.

The solid is filtered off, washed with cold chlorobenzene and dried in vacuo. This gives 512 g (purity: 99 of 2,2'-bis(diphenylphosphinylmethyl)-1,1'-binaphthyl as colorless crystals having a melting point of from 287 to L I_ II I 14 289 0 C, corresponding to 75 total yield based on 2,2'dimethyl-1,1'-binaphthyl used.

Composition according to GC analysis (in mol without solvent: 80 of 2,2'-bis(bromomethyl)-1,l'-binaphthyl 2 of 2-bromomethyl-2'-methyl-l,l'-binaphthyl 13 of 2-dibromomethyl-2'-bromomethyl-l,l'binaphthyl.

Example 2 Preparation using a reaction mixture A With exclusion of moisture, 282.4 g (1.0 mol) of 2,2'dimethyl-l,l'-binaphthyl and 373.8 g (2.1 mol) of N-bromosuccinimide are suspended in 1.7 1 of chlorobenzene in a 4 1 glass flask and are illuminated with a UV immersion lamp for 8 hours at from 5 to 10 0 C. The precipitated succinimide is filtered off, the solution is extracted twice with 200 ml of water each time, dried using sodium sulfate and filtered. The filtrate (reaction mixture is transferred to a 4 1 four-neck flask S 20 fitted with stirrer, dropping funnel, reflux condenser and internal thermometer and is heated to 125 0 C. 488.6 g (2.0 mol) of propyl diphenylphosphinite are then slowly added dropwise, with n-propyl bromide distilling off.

After the end of the addition, the mixture is heated under reflux for a further two hours and is then cooled to 0°C. The solid is filtered off, washed with cold chlorobenzene and dried in vacuo. This gives 502.5 g of 2,2'-bis(diphenylphosphinylmethyl)-1,1'-binaphthyl (purity: 99 as colorless crystals having a melting point of from 287 to 289 0 C, corresponding to 73.5 total yield based on 2,2'-dimethyl-l,l'-binaphthyl used.

Composition according to GC analysis (in mol without solvent: 68 of 2,2'-bis(bromomethyl)-1,1'-binaphthyl 15 of 2-bromomethyl-2'-methyl-l,l'-binaphthyl 15 13 of 2-dibromomethyl-2'-bromomethyl-1,1'binaphthyl.

Example 3 Preparation using a reaction mixture B With exclusion of moisture, 282.4 g (1.0 mol) of 2,2'dimethyl-1,l'-binaphthyl, 373.8 g (2.1 mol) of N-bromosuccinimide and 500 mg of benzoyl peroxide are suspended in 1.7 1 of chlorobenzene in a 4 1 glass flask and are stirred for 3.5 hours at the boiling point. The precipitated succinimide is filtered off, the solution is extracted twice with 200 ml of water each time and once with 100 ml of Na 2

SO

3 solution, dried using sodium sulfate and filtered. The filtrate (reaction mixture B)* is transferred to a 4 1 four-neck flask fitted with stirrer, dropping funnel, reflux condenser and internal thermometer and is heated to 125 0 C. 460.5 g (2.0 mol) of ethyl diphenylphosphinite are then slowly added dropwise, with ethyl bromide distilling off. After the end of the addition, the mixture is heated under reflux for a further two hours and is then cooled to 0 C. The solid is filtered off, washed with cold chlorobenzene and dried in va 1o. This gives 443.8 g (purity: 99 of 2,2'-bis- (Jiphenylphosphinylmethyl)-1,1'-binaphthyl as colorless crystals having a melting point of from 287 to 289 0

C,

corresponding to 65 total yield based on 2,2'-dimethyl- 1,1'-binaphthyl used.

Composition according to GC analysis (in mol without solvent: 6: 8 of 2,2'-bis(bromomethyl)-l,1'-binaphthyl 15 of 2-bromomethyl-2'-methyl-l,1'-binaphthyl 13 of 2-dibromomethyl-2'-bromomethyl-l,1'binaphthyl.

16 Example 4 2,2'-Bis[bis(3-fluorophenyl)phosphinylmethyl]-1,1'binaphthyl While stirring under nitrogen, 8.8 g (33 mmol) of ethyl bis(3-fluorophenyl)phosphinite are slowly added dropwise to a solution of 7.27 g (16.6 mmol) of 2,2'-bis(bromomethyl)-1,1'-binaphthyl in 40 ml of o-xylene, which solution has been heated to 120°C, with ethyl bromide distilling off. After the end of the addition, the mixture is heated under reflux for a further two hours and is then cooled to 0 C. The solid is filtered off, washed with cold o-xylene and dried in vacuo. This gives 11.5 g (91 of colorless crystals having a melting point of 280-284 0

C.

3 1 P-NMR: 6 (CDC1 3 27.3 ppm Example 2,2'-Bis[bis(4-fluorophenyl)phosphinylmethyl]-1,1'binaphthyl While stirring under nitrogen, 10.70 g (0.04 mol) of 20 ethyl bis(4-fluorophenyl)phosphinite are added dropwise to a solution of 8.80 g (0.02 mol) of 2,2'-bis(bromomethyl)-1,1'-binaphthyl in 40 ml of o-xylene, which Ssolution has been heated to 135°C. After the end of the addition, the mixture is heated under reflux for a S 25 further 1.5 hours. After cooling to room temperature, the precipitated crystals are filtered off with suction and washed with xylene. This gives 14.1 g (94 of colorless crystals having a melting point of 211-214 0

C.

3 1 P-NMR: 6 (CDC1 3 28.2 ppm I II -I 17 Example 6 2,2'-Bis[bis(2-methylphenyl)phosphinylmethyl]-1,1'-binaphthyl While stirring under nitrogen, 21.5 g (83 mmol) of ethyl bis(2-methylphenyl)phosphinite are slowly added dropwise to a solution of 18.4 g (42 mmol) of 2,2'-bis(bromomethyl)-1,1'-binaphthyl in 100 ml of o-xylene, which solution has been heated to 120 0 C, with ethyl bromide distilling off. After the end of the addition, the mixture is heated under reflux for a further two hours and is then cooled to 0 C. The solid is filtered off, washed with cold o-xylene and dried in vacuo. This gives 25.1 g (81 of colorless crystals having a melting point of 231-234 0

C.

31 P-NMR- 6 (CDC13) 30.5 ppm Example 7 2,2' -Bis [bis (3-trifl-ioromethylphenyl)phosphinylmethyl] l,l'-binaphthyl While stirring under nitrogen, 20,1 g (55 mmol) of ethyl S 20 bis(3-trifluoromethylphenyl)phosphinite are slowly added dropwise to a solution of 11.0 g (25 mmol) of 2,2'bis(bromomethyl)-l,1'-binaphthyl in 80 ml of o-xylene, which solution has been heated to 120 0 C, with ethyl bromide distilling off. After the end of the addition, the mixture is heated under reflux for a further two hours and is then cooled to 0°C. The solid is filtered off, washed with cold o-xylene and dried in vacuo. T1is gives 16.1 g (68 of colorless crystals.

31 P-NMR: 6 (CDC1 3 27.1 ppm Example 8 (Arbusov in ethyl acetate) While stirring under nitrogen, 88.5 g (385 mmol) of ethyl 18 diphenylphosphinite are slowly added dropwise to a solution of 77.0 g (175 mmol) of 2,2'-bis(bromomethyl)l,1'-binaphthyl in 400 ml of ethyl acetate, which solution has been heated to 78°C, and ethyl bromide is simultaneously distilled off via an 80 cm Vigreux column.

After the end of the addition, the mixture is heated under reflux for a further two hours and is then cooled to 0 C. The solid is filtered off, washed with cold ethyl acetate and dried in vacuo. This gives 85.0 g (71 of colorless crystals having a melting point of 287-289 0

C.

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Claims

1. A process for preparing 2,2'-bis(diphenylphosphinyl- methyl)-1,1'-binaphthyls, which comprises reacting a reaction mixture prepared in a solvent by reaction of 2,2'-dimethyl-l,l'-binaphthyl with a brominating agent and containing 2,2'-bis(bromomethyl)-1,1'- binaphthyl and further brominated binaphthyls, if desired after removal of unreacted brominating agent, reacted brominating agent and/or solvent, with an alkyl diphenylphosphinite of the formula RO-P(Ph-(R')n) 2 where R is an alkyl radical having from 1 to 5 carbon atoms, Ph is phenyl, R' is an alkyl radical having from 1 to 4 carbon atoms, CF 3 fluorine, chlorine or bromine and n is 0, 1 or 2, at from 70 to 1800C in the presence or absence of a further solvent.

2. The process as claimed in claim 1, wherein 2,2'- dimethyl-l,l'-binaphthyl and the solvent are used in S* a weight ratio of 1:(3 to 40), in particular 1:(4 to 20 20), preferably 1:(5 to e

3. The process as claimed in claim 1 or 2, wherein the S" solvent used is a monochlorinated or polychlorinated benzene, a monochlorinated or polychlorinated aliphatic hydrocarbon, an ester of an aliphatic carboxylic acid having from 1 to 6 carbon atoms and an aliphatic alcohol having from 1 to 4 carbon atoms or a mixture thereof. e

4. The process as claimed in one or more of claims 1 to 3, wherein the solvent used is chlorobenzene or dichlorobenzene. The process as claimed in one or more of claims 1 to 3, wherein the solvent used is a mixture of chloro- benzene and dichlorobenzene. ~I 20

6. The process as claimed in one or more of claims 1 to wherein 2,2'-dimethyl-l,l'-binaphthyl and the brominating agent are reacted under the action of light having a wavelength of from 10 5 to 10 8 m at from -10 to 75 0 C, in particular from -5 to +50 0 C, preferably from 0 to 40 0 C.

7. The process as claimed in one or more of claims 1 to wherein 2,2'-dimethyl-1,1'-binaphthyl and the brominating agent are reacted under the action of a free-radical former at from 25 to 150 0 C, in particu- lar from 40 to 135 0 C.

8. The process as claimed in one or more of claims 1 to 7, wherein 2,2'-dimethyl-1,l'-binaphthyl is reacted with N-bromosuccinimide as brominating agent.

9. The process as claimed in one or more of claims 1 to 8, wherein 2,2'-dimethyl-l,1'-binaphthyl and N-bromosuccinimide are used in a molar ratio of 1:(1.5 to in particular 1:(1.8 to pre- ferably 1:(1.9 to 2.2).

10. The process as claimed in one or more of claims 6 to 9, wherein the succinimide formed as reacted bromi- nating agent is removed after bromination.

11. The process as claimed in one or more of claims 6 to wherein succinimide is removed, if desired after S" 25 cooling, by filtration.

12. The process as claimed in one or more of claims 6 to 11, wherein succinimide is removed by extraction with water.

13. The process as claimed in one or more of claims 6 to 12, wherein succinimide is removed in a first step by filtration and in a second step by extraction with water. 0 21

14. The process as claimed in one or more of claims 1 to 13, wherein the reaction mixture is reacted with the alkyl diphenylphosphinite of the formula RO-P(Ph-(R')n) 2 at from 100 to 170 0 C, in particular from 120 to 160 0 C. The process as claimed in one or more of claims 1 to 14, wherein the alkyl diphenylphosphinite of the formula RO-P(Ph-(R')n) 2 is used in a molar ratio of (1.8 to in particular (1.9 to preferably (2 to based on 2,2'-dimethyl-l,l'-binaphthyl used.

16. The process as claimed in one or more of claims 1 to wherein the alkyl diphenylphosphinite of the formula RO-P(Ph-(R')n) 2 which is used is a alkyl diphenylphosphinite or a mixture of these esters.

17. The process as claimed in one or more of claims 1 to 16, wherein the alkyl diphenylphosphinite of the formula RO-P(Ph-(R')n) 2 which is used is methyl 20 diphenylphosphinite, ethyl diphenylphosphinite, isopropyl diphenylphosphinite, n-propyl diphenyl- phosphinite, ethyl bis(3-fluorophenyl)phosphinite, ethyl bis(4-fluorophenyl)phosphinite, ethyl bis(2- methylphenyl)phosphinite and/or ethyl bis(3-tri- fluoromethylphenyl)phosphinite.

18. The process as claimed in one or more of claims 1 to 17, wherein a further solvent which has a boiling point higher than that of the solvent originally used is added prior to the reaction or during the reaction or after the reaction of the reaction mixture with the alkyl diphenylphosphinite and the solvent originally used is distilled off.

19. The process as claimed in one or more of claims 1 to 17, wherein o-xylene, m-xylene, p-xylene, mixtures -NOW~ 22 of these xylenes and/or mesitylene are added as a further solvent during the reaction of the reaction mixture with the alkyl diphenyiphosphinite and chlorobenzene and/or dichlorobenzene are distilled off as the solvent originally used. A compound of the formula 0 R 0 (R where R' is an alkyl radical having from 1 to 4 carbon atoms, CF 3 fluorine, chlorine or bromine and n is 1 or 2.

21. A compound of the formula 0 where R' is methyl, CF 3 or flurrine and n is 1 or 2.

22. The compou-21s 2,2' -bis~bis(3-fluorophenyl)phos- phinylmethyl) -l,l'-binaphthyl, 2,2'-bis Ebis (4-fluo- rophenyl)phosphinylmethylJ -binaphthyl, 2,2' bis [bis(2-methylphenyl)phosphinylmethy1] -bi- naphthyl and 2,2' -bis tbis (3-trifluoromethylphenyl) phosphinylmethylJ -binaphthyl. -23-

23. A process for preparing 2,2' -his(dipheniylph)osphiniylmcthyvl) -1.]X -binaphthyls according to any one of claims I to 19, and novel 2,2' -bis(diplhenylphosphiinylm-ethiyl( 1, 1' -binaphthyls according to any) one of' claims 20 to 22 substantially as hercinbefore described with reference to the examples. DATED this 15th day of March 1995 110EXA-1 S T AKTJENGESELL SCI IAFI By Its P~atent Attorneys DAVIES ('OLIISON ('AVF HOE 94/F 071 J Abstract Process for preparing 2,2' -bis (diphenylphosphinylmethyl) l,l'-binaphthyls and new compounds from this class of substances. The present invention relates to a process for preparing 2,2'-bis(diphenylphosphinylmethyl)-1,1'-binaphthyls, by reacting a reaction mixture prepared in a solvent by reaction oi 2,2'-dimethyl-1,l'-binaphthyl with a bromina- ting agent and containing 2,2'-bis(bromomethyl)-1,1'- binaphthyl and further brominated binaphthyls, if desired after removal of unreacted brominating agent, reacted brominating agent and/or solvent, with an alkyl diphenyl- phosphinite of the formula RO-P(Ph-(R')n) 2 where R is an alkyl radical having from 1 to 5 carbon atoms, Ph is phenyl, R' is an alkyl radical having from 1 to 4 carbon atoms, CF 3 fluorine, chlorine or bromine and n is 0, 1 S' or 2, at from 70 to 180 0 C in the presence or absence of a further solvent. The invention further relates to compounds of the formula 0 "I where R' is an alkyl radical having from 1 to 4 carbon atoms, CF 3 fluorine, chlorine or bromine and n is 1 or 2. L _I L ~l C