JP2002128752A - Method for producing bistriflate derivative of binaphthol - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for production by which the pressure in a reactor is scarcely raised without requiring a special reaction such as a pressure- resistant reactor for producing a bistriflate derivative of a binaphthol using trifluoromethanesulfonyl fluoride having high volatility at normal temperature under an atmospheric pressure. SOLUTION: This method for producing a compound represented by general formula 1 comprises reacting a compound represented by general formula 2 with trifluoromethanesulfonyl fluoride in the presence of an organic base in a polar solvent. N,N-Dimethylforamamide, N,N-dimethylacetamide, 1-methyl-2- pyrrolidinone or acetonitrile is cited as the polar solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to 2,2'-bis (trifluoromethanesulfonyloxy) -1,1'-
The present invention relates to a method for producing binaphthyl. The material is useful as a precursor of 2,2′-bis (diphenylphosphino) -1,1′-binaphthyl (hereinafter “BINAP”), which is important as a chiral ligand for catalytic asymmetric synthesis. is there.

[0002]

2. Description of the Related Art As a method for producing a bistriflate form of binaphthol, for example, Tetrahedron L
etters 1990, p. 985, U.S. Pat.
No. 9771, Organic Synthese
s Volume 76, page 6, which is synthesized by reacting binaphthol with trifluoromethanesulfonic anhydride in the presence of an organic base. Further, WO 99/36397 describes a method for producing a bisperfluoroalkanesulfonate of binaphthols as a precursor of BINAPs, wherein binaphthols are converted to perfluoroalkanesulfonyl in the presence of an organic base. Halide (C _n F _{2n + 1} SO ₂ X, where n is 4 to 10, X = F,
Cl), or perfluoroalkane sulfonic anhydride _{((C n F 2n + 1} SO 2) 2 O, where, n is synthesized by reacting a 4 to 10).

[0003]

As for the process for producing the bistriflate of binaphthol, only an example using trifluoromethanesulfonic anhydride as a trifluoromethanesulfonylating agent is known.

[0004] Trifluoromethanesulfonic anhydride is
As shown in the following reaction formula, it is produced by hydrolyzing trifluoromethanesulfonyl fluoride obtained by electrolytic fluorination to convert it to trifluoromethanesulfonic acid, followed by dehydration condensation.

[0005] CF ₃ SO ₂ F → CF ₃ SO ₃ H →
(CF ₃ SO ₂ ) ₂ O Although trifluoromethanesulfonic anhydride has two trifluoromethanesulfonyl groups, one is a leaving group (TfO ⁻ = CF ₃ SO ₃ ⁻ ). To work, only one is introduced into the bistriflate form of binaphthol.

Therefore, for the above two reasons, it is clearly more advantageous to use trifluoromethanesulfonyl fluoride as trifluoromethanesulfonylating agent than to use trifluoromethanesulfonic anhydride.

However, trifluoromethanesulfonyl fluoride has a high volatility (at a boiling point of −20 ° C.) at normal temperature and normal pressure, and is very difficult to handle.

In order to avoid this problem, WO 99/3
No. 6397 discloses that a perfluoroalkanesulfonylating agent having low volatility at normal temperature and normal pressure, for example, perfluoro-1-butanesulfonyl fluoride (boiling point
64 [deg.] C.) and without using a special reaction apparatus such as a pressure-resistant reaction vessel, by adopting general sulfonylation reaction conditions, the target perfluoro-1-butanesulfonylation can be carried out at room temperature. It demonstrates that it can be carried out at normal pressure.

However, even in the above publication, since the final purpose is the synthesis of BINAPs, it is very difficult to introduce leaving groups having many fluorine atoms from the viewpoint of atomic economy (atom economy). Disadvantageous.

[0010]

SUMMARY OF THE INVENTION The present invention is directed to an ultimate solution to the above-mentioned problems, that is, the production of a bistriflate of binaphthol using trifluoromethanesulfonyl fluoride having high volatility at normal temperature and pressure. It is an object of the present invention to provide a reaction condition that does not require a special reaction apparatus such as a pressure-resistant reaction vessel.

[0011]

The present inventors have conducted intensive studies to solve the above-mentioned problems. As a result, the use of a polar solvent as a reaction solvent allows the reaction to proceed rapidly at a low temperature, and to reduce The pressure hardly increased, and reaction conditions that did not substantially require a special reaction apparatus such as a pressure-resistant reaction vessel could be found, and the present invention was achieved.

That is, the present invention provides the following:

[0013]

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A process for producing a compound represented by the formula:

[0015]

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A method for producing a compound represented by the formula 1, comprising reacting the compound represented by the formula (II) with trifluoromethanesulfonyl fluoride in a polar solvent in the presence of an organic base.

Further, the present invention provides a method for producing a liquid crystal device according to the present invention, wherein the polar solvent is N,
This is a production method which is N-dimethylformamide, N, N-dimethylacetamide, 1-methyl-2-pyrrolidinone, or acetonitrile.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a method for producing a bistriflate of binaphthol of the present invention will be described in detail.

The starting material used in the present invention is binaphthol, and its stereochemistry may be R-form, S-form or racemic-form. Since racemization does not occur in this reaction, an R-isomer, an S-isomer, or a racemic bis-triflate can be obtained by appropriately using stereoisomers according to the purpose.

The trifluoromethanesulfonylating agent used in the present invention is trifluoromethanesulfonyl fluoride.

The amount of the trifluoromethanesulfonylating agent used in the present invention may be 2 mol or more, preferably 2 to 10 mol, and more preferably 2 to 5 mol, per mol of binaphthol.

The organic base used in the present invention includes trimethylamine, triethylamine, diisopropylethylamine, tri-n-propylamine, tri-n-butylamine, dimethyllaurylamine, dimethylaminopyridine, N, N-dimethylaniline, dimethylbenzylamine, , 8-diazabicyclo (5,4,0) undecene-7,1,4-diazabicyclo (2,2,2) octane, pyridine, 2,4,6-trimethylpyridine, pyrimidine, pyridazine, 3,5-lutidine, 2,6-lutidine, 2,4-lutidine, 2,5-lutidine, 3,4-
Lutidine and the like. Among them, trimethylamine, triethylamine, diisopropylethylamine,
Tri-n-propylamine is preferred, and triethylamine is particularly preferred.

The amount of the organic base used in the present invention may be 2 mol or more per 1 mol of binaphthol, preferably 2 to 10 mol, and more preferably 2 to 5 mol.

The polar solvent used in the present invention is
N, N-dimethylformamide, N, N-diethylformamide, N, N-dimethylacetamide, 1-methyl-2-pyrrolidinone, 1,3-dimethyl-2-imidazolidinone, hexamethylphosphoric triamide, dimethylsulfoxide, Acetonitrile, propionitrile, benzonitrile and the like can be mentioned. Among them, N, N-dimethylformamide, N, N-dimethylacetamide, 1
-Methyl-2-pyrrolidinone and acetonitrile are preferred, and N, N-dimethylformamide and acetonitrile are more preferred. These polar solvents can be used alone or in combination.

A feature of the present invention resides in that a polar solvent is used as a reaction solvent, and the effect of the solvent will be described in detail. In general, when a highly volatile reagent is used, the load on the pressure resistance of the reactor can be minimized by promptly proceeding the reaction at the lowest possible reaction temperature (= low vapor pressure). Therefore, the conversion ratios of the reaction around the boiling point (−20 ° C.) of trifluoromethanesulfonyl fluoride depending on the reaction solvent were compared. As a comparative control, methylene chloride used in Example 1 as the most preferred reaction solvent in WO99 / 36397 was employed. The results of the comparative experiment are summarized in Table 1 below. For detailed reaction conditions and experimental procedures, see the corresponding comparative examples and examples described below.

[0026]

[Table 1]

From the results shown in Table 1, the use of a polar solvent allows the reaction to proceed rapidly at a low temperature. In Examples 3 and 4, even though the temperature finally rises to 0 ° C. Since most of the trifluoromethanesulfonyl fluoride was already consumed, the pressure in the reaction vessel hardly increased, and substantially no special reaction device such as a pressure-resistant reaction vessel was required.

By using a polar solvent as described above,
The reason why the reaction proceeded rapidly at low temperature is as follows. 1. The solubility of binaphthol in the reaction solvent at a low temperature was remarkably improved (especially in a racemic compound having poor solubility). Two points can be mentioned that the trifluoromethanesulfonylation reaction itself was accelerated.

The polar solvent used in the present invention may be used in an amount that is at least sufficient to ensure sufficient solubility for the reaction to proceed rapidly at a low temperature.
The amount is preferably 1 to 10 L, and particularly preferably 1.5 to
5 L is more preferred.

The reaction temperature in the present invention is set within a range from a temperature at which trifluoromethanesulfonyl fluoride (boiling point: -20 ° C.) can be liquefied and injected to a temperature at which the pressure in the reaction vessel does not rise significantly. Particularly, -60 to 10 ° C is preferable,
-50 to 0 ° C is more preferable.

In the post-treatment in the present invention, a crude product can be obtained by performing a usual post-treatment operation after the reaction is completed. The obtained crude product may be subjected to purification operations such as activated carbon, recrystallization, and column chromatography, if necessary, to obtain the desired bistriflate of binaphthol with high purity.

Hereinafter, embodiments of the present invention will be described specifically with reference to Examples, but the present invention is not limited to these Examples.

Comparative Example 1 CF ₃ SO ₂ F-Et ₃ N /
CH ₂ Cl ₂ / −30 ° C. for 1 hour (±) -1,1′-bi-2-naphthol 2.86 g in methylene chloride 22 ml (2.2 ml / mmol)
(10 mmol, 1 eq) and triethylamine 2.9
9 g (29.6 mmol, 2.96 eq) was added and dissolved at room temperature with stirring, and cooled to -30 ° C (solidification /
3.51 g (23.1 mmol, 2.31 g) of trifluoromethanesulfonyl fluoride at the same temperature.
eq) was liquefied and injected and left for 1 hour (partial dissolution / stirring impossible). At the same temperature, 120 ml of 1N hydrochloric acid was added to the reaction mixture, extracted with 50 ml of methylene chloride, and the conversion was determined by liquid chromatography to be 23%. Liquid chromatography conditions: YMC-Pack ODS-AM312,
CH ₃ CN: H ₂ O = 70: 30, 220 nm, column temperature 30 ° C., flow rate 1 ml / min

Example 1 CF ₃ SO ₂ F-Et ₃ N /
CH ₃ CN / −30 ° C. for 1 hour 2.86 g of (±) -1,1′-bi-2-naphthol in 22 ml of acetonitrile (2.2 ml / mmol)
(10 mmol, 1 eq) and triethylamine 2.9
9 g (29.6 mmol, 2.96 eq) was added and dissolved at room temperature with stirring, and cooled to -30 ° C (solidification /
3.51 g (23.1 mmol, 2.31 g) of trifluoromethanesulfonyl fluoride at the same temperature.
eq) was liquefied and injected and left for 1 hour (partial dissolution / stirring impossible). At the same temperature, 120 ml of 1N hydrochloric acid was added to the reaction mixture, extracted with 50 ml of methylene chloride, and the conversion was determined by liquid chromatography to find that the conversion was 73%. Liquid chromatography conditions: Same as Comparative Example 1.

Example 2 CF ₃ SO ₂ F-Et ₃ N /
DMF / -30 ° C for 1 hour N, N-dimethylformamide 22ml (2.2ml
/ Mmol) to 2.86 g (10 mmol, 1 eq) of (±) -1,1′-bi-2-naphthol and 2.99 g (29.6 mmol, 2.96 eq) of triethylamine.
At room temperature with stirring, cooled to -30 ° C (homogeneous solution / stirable), and treated at the same temperature with trifluoromethanesulfonyl fluoride 3.51 g (23.1 m).
mol, 2.31 eq), and stirred for 1 hour (homogeneous solution / stirring possible). At the same temperature, 120 ml of 1N hydrochloric acid was added to the reaction mixture, and the mixture was extracted with 50 ml of methylene chloride.
The conversion was determined by liquid chromatography to be 85%. Liquid chromatography conditions: Same as Comparative Example 1.

Comparative Example 2 CF ₃ SO ₂ F-Et ₃ N /
CH ₂ Cl ₂ / −30 ° C. → 0 ° C. · 1 hour (±) -1,1′-bi-2-naphthol 2.86 g in 22 ml (2.2 ml / mmol) of methylene chloride
(10 mmol, 1 eq) and triethylamine 2.9
9 g (29.6 mmol, 2.96 eq) was added and dissolved at room temperature with stirring, and cooled to -30 ° C (solidification /
3.51 g (23.1 mmol, 2.31 g) of trifluoromethanesulfonyl fluoride at the same temperature.
eq) was liquefied and injected, and left at 0 ° C. for 1 hour (partial dissolution / stirring was not possible). At the same temperature, 1N hydrochloric acid 120 was added to the reaction mixture.
The mixture was extracted with 50 ml of methylene chloride, and the conversion was determined by liquid chromatography to be 73%. Liquid chromatography conditions: Same as Comparative Example 1.

Example 3 CF ₃ SO ₂ F-Et ₃ N /
CH ₃ CN / −30 ° C. → 0 ° C. · 1 hour (±) -1,1′-bi-2-naphthol 2.86 g in acetonitrile 22 ml (2.2 ml / mmol)
(10 mmol, 1 eq) and triethylamine 2.9
9 g (29.6 mmol, 2.96 eq) was added thereto, and the mixture was dissolved with stirring at room temperature and cooled to -30 ° C (solidification /
3.51 g (23.1 mmol, 2.31 g) of trifluoromethanesulfonyl fluoride at the same temperature.
eq) was liquefied and injected and stirred at 0 ° C. for 1 hour (homogeneous solution / stirable). At the same temperature, 1N hydrochloric acid 120 m was added to the reaction mixture.
The mixture was extracted with 50 ml of methylene chloride, and the conversion was determined by liquid chromatography to be> 99%. Liquid chromatography conditions: Same as Comparative Example 1.

Example 4 CF ₃ SO ₂ F-Et ₃ N /
DMF / -30 ° C → 0 ° C for 1 hour N, N-dimethylformamide 22ml (2.2ml
/ Mmol) to 2.86 g (10 mmol, 1 eq) of (±) -1,1′-bi-2-naphthol and 2.99 g (29.6 mmol, 2.96 eq) of triethylamine.
And dissolved at room temperature with stirring, cooled to −30 ° C. (homogeneous solution / stirable), and treated at the same temperature with 3.51 g (23.1 mm) of trifluoromethanesulfonyl fluoride.
ol, 2.31 eq) was liquefied and injected, followed by stirring at 0 ° C. for 1 hour (homogeneous solution / stirable). 1N to the reaction mixture at the same temperature
Hydrochloric acid (120 ml) was added, methylene chloride (50 ml) was extracted, and the conversion was determined by liquid chromatography.
Met. Liquid chromatography conditions: Same as Comparative Example 1.

Example 5 CF ₃ SO ₂ F-Et ₃ N /
CH ₃ CN / −50 ° C. → 0 ° C., 1 hour (R)-(+)-1,1′-bi-2-naphthol 2 in 200 ml (2 ml / mmol) of acetonitrile
8.6 g (100 mmol, 1 eq) and 29.3 g (290 mmol, 2.9 eq) of triethylamine were added, and the mixture was dissolved at room temperature with stirring, cooled to -50 ° C (suspension / stirring was possible), and trifluoride was added at the same temperature. 39.5 g (260 mmol, 2.95 g) of methanesulfonyl fluoride
6 eq), and the temperature was raised to 0 ° C. over 1 hour (homogeneous solution / stirable, pressure in reaction vessel: 〜0.03 M)
Pa). At the same temperature, 400 ml of 1N hydrochloric acid was added to the reaction mixture, extracted with 600 ml of toluene, the organic layer was concentrated, and a crude product was obtained in a quantitative yield. The conversion was determined by liquid chromatography of the crude product and was> 99%. The crude product was recrystallized from 110 ml of n-hexane to obtain 44.9 g of white crystals (total yield: 82%). The liquid chromatographic purity of the recrystallized product was> 99%. Liquid chromatography conditions: Same as Comparative Example 1.

Further, it was confirmed from the optical rotation of the recrystallized product that racemization did not occur. Specific rotation: [α] ²⁶ _D = -140.9 ° (c = 1.04)
4, Literature for CHCl ₃ ) (S) -bistriflate: [α] ²² _D = +
142 ° (c = 1.035, CHCl ₃ ) Other equipment data are literature values (Organic Synth)
eses, 76, 6). Also, (S)-
The same procedure was applied to (-)-1,1'-bi-2-naphthol to obtain a bistriflate of (S)-(-)-1,1'-bi-2-naphthol.

Example 6 CF ₃ SO ₂ F-Et ₃ N /
DMF / -50 ° C → 0 ° C for 1 hour N, N-dimethylformamide 200ml (2ml /
mmol), 28.6 g (100 mmol, 1 eq) of (R)-(+)-1,1′-bi-2-naphthol and 29.3 g (290 mmol, 2.9 e) of triethylamine.
q), and dissolved at room temperature with stirring.
(Homogeneous solution / stirable), and at the same temperature, 39.5 g of trifluoromethanesulfonyl fluoride (260 m
mol, 2.6 eq) and liquefied and injected at 0 ° C. for 1 hour.
(Homogeneous solution / stirable, pressure in reaction vessel ~: 0.03 MPa). At the same temperature, 400 ml of 1N hydrochloric acid was added to the reaction mixture, extracted with 600 ml of toluene, the organic layer was concentrated, and a crude product was obtained in a quantitative yield. The conversion was determined by liquid chromatography of the crude product and was> 99%. The crude product was recrystallized from 110 ml of n-hexane to obtain 43.1 g of white crystals (total yield: 78).
%). The liquid chromatographic purity of the recrystallized product was> 99%. Liquid chromatography conditions: Same as Comparative Example 1.

Further, it was confirmed from the optical rotation of the recrystallized product that racemization did not occur. Specific rotation: [α] ²⁶ _D = -140.3 ° (c = 1.01)
0, CHCl ₃ ) Literature value of (S) -bistriflate: described in Example 5. Other instrument data is literature value (Organic Synth).
eses, 76, 6).

Further, (S)-(-)-1,1'-bi-2
-Similarly for naphthol, (S)-(-)-
A bistriflate of 1,1′-bi-2-naphthol was obtained.

[0044]

According to the present invention, in a method for producing a bistriflate of binaphthol using trifluoromethanesulfonyl fluoride having high volatility at normal temperature and normal pressure, it can be produced without requiring a special reaction apparatus such as a pressure-resistant reaction vessel.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Katsu Kuriyama 2805 Imafukunakadai, Kawagoe-shi, Saitama Central Research Institute of Chemical Research, Ltd. (72) Inventor Mitsuru Tanuma 3-7-1, Kandanishikicho, Chiyoda-ku, Tokyo Central F-term in Glass Co., Ltd. (reference) 4H006 AA02 AC61 BA51 BB20 BB21 BB24 BB42 4H039 CA80 CD10 CD20

Claims (2)

[Claims] (1) Formula 1 A method for producing a compound represented by the formula: In a polar solvent in the presence of an organic base,
A method for producing a compound represented by the formula 1, comprising reacting with trifluoromethanesulfonyl fluoride. 2. The method according to claim 1, wherein the polar solvent is N, N-dimethylformamide, N, N-dimethylacetamide, 1-methyl-2.
The production method according to claim 1, wherein the production method is pyrrolidinone or acetonitrile.