JPS5948816B2 - Method for producing 1-chloro-1,3-diphenylpropane - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the reaction of benzyl chloride and styrene, and its purpose is to produce 1-chloro-1,3-diphenylpropane, which is a 1:1 adduct thereof, in a high yield. be.

The addition reaction of chloride with olefins has long been well studied in the series of Friedel-Crafts reactions.

For example, α-chloroethylbenzene is a mixture of isobutylene and Z
nCl2 catalyst gives the l:1 adduct 2-methyl-2-chloro-4-phenylpentane in 95% yield. In addition, reaction with styrene gives 1-chloro-1,3-diphenylbutane with a yield of 50% (G, A, O
lah)"Friedel Crafts and Re-1ated Reactions"", Vol. 2, P.
768, In-tersciencePublish
rs, Inc., New York). however,
Primary chlorides such as benzyl chloride do not undergo addition reactions with olefins, and the olefins are alkylated to the aromatic ring of benzyl chloride. 9 However, according to the present invention, by using a catalyst consisting of triphenylphosphine and metallic iron, it is possible to carry out an addition reaction between benzyl chloride and styrene, which does not proceed with a Friedel-Crafts catalyst, and the 1:1 adduct can A certain 1-chlorol,3-diph5enylpropane can be produced with good yield.

Triphenylphosphine, which is a catalyst component in the present invention, reacts with benzyl chloride during the reaction process to form a phosphonium salt [Ph3P-CH2Ph]+Cl- (Ph is a phenyl group) and exhibits a catalytic action. It is to be noted that the metal iron, which is another catalyst component, is preferably granular and has a smaller particle size, and generally iron powder of 20 mesh or less, particularly 200 mesh or less is preferably used. The mixing ratio of the above catalyst component triphenylphosphine and metal iron is generally used in the range of 0.1 to 100 mmol of triphenylphosphine per 1 milligram atom of metal penta-iron. In order to recover a complex salt of a quaternary salt of phosphine and ferric chloride, it is desirable to use both catalyst components in an equimolar ratio. In the reaction system of the present invention, the concentration of the above-mentioned catalyst is sufficient at a ratio of 0.001 to 0.05 moles of triphenylphosphine per mole of styrene, and although higher concentrations may be used, it is not economical and generally 5 Preferred concentration is 0.005 to 0.3 mol of triphenylphosphine per 1 mol of styrene.

Further, in the present invention, the ratio of benzyl chloride and styrene used in the reaction is about 1:1 to about 10:1, preferably about 2
:1 to about 4:1.

In addition, the conditions for the reaction of the present invention are not particularly limited, and are generally carried out using ordinary equipment and means, under normal pressure to increased pressure, and from about 95°C to 100°C.
Performed at 30°C. Furthermore, the reaction of the present invention can be carried out using a solvent that easily dissolves the catalyst component triphenylphosphine, such as alcohols such as isopropyl alcohol and n-butyl alcohol, as well as dimethylformamide. The yield of 1-chloro-1,3-diphenylpropane, which is a 1:1 addition product of 1:1 and styrene, can be improved.

1-Chlor-1,3-diphenylpropane obtained in the present application is used as various raw materials or intermediate raw materials, such as l-(1,3-diarylpropyl)piperazine used in neurotropic agents, psychotherapeutic agents, etc. It is suitably used as a raw material.

Example 1 Benzyl chloride 40ml (0.348mol), styrene 1
1.4 m1 (0.1 mol) and 524 m9 of triphenylphosphine (2 mmol and 11 mol of metal iron) as a catalyst.
(2 milligram atoms) were charged into a round bottom flask.

After purging the reaction system with nitrogen gas, the reaction was carried out at a temperature of 110° C. for 4 hours while stirring with a magnetic stirrer. Metallic iron was eluted into the reaction solution, and the reaction solution became a yellow homogeneous solution. After cooling, water washing was performed twice to remove catalyst residues and the like. After washing with water, the reaction solution became a colorless solution. Next, the reaction solution was distilled under reduced pressure to reduce the boiling point to 134-1.
Fraction 9.1f1 was distilled at 35°C/2mmH9. This was confirmed to be 1-chloro-1,3-diphenylpropane by gas chromatography, infrared (IR), and nuclear magnetic resonance (NMR) spectra. The yield from styrene is 39.5 mol%. Example 2 5ml of n-butyl alcohol was added to the reaction system in Example 1.
The reaction was carried out under exactly the same conditions as in Example 1, except that the following was added as a solvent.

After the reaction, n-butyl alcohol was removed from the reaction solution by washing with water. 1-chloro-1,3-diphenylpropane is 10.89 (yield from styrene 46.9 mol%)
Obtained.

Comparative Example 1 A reaction was carried out at a temperature of 110° C. under exactly the same charging conditions as in Example 1, except that triphenylphosphine was removed from the catalyst component.

About 1 hour after the start of the reaction, a styrene polymerization reaction accompanied by intense heat generation was observed. The reaction solution becomes a yellow viscous liquid. When the reaction solution was poured into 500 ml of methanol, a viscous yellow oil was obtained. This was separated from methanol by decantation, and methanol and benzyl chloride were removed under vacuum, yielding 14.99 yellow solids.
This was fixed with polystyrene from the IR vector.
Comparative Example 2 The reaction between benzyl chloride and styrene was carried out exactly as in Example 1, except that triphenylphosphine was removed from the charging conditions of Example 2, and only metallic iron was used as a catalyst in an n-butyl alcohol solvent. The same reaction procedure was used.

Boiling point 125-138℃/2mmH9 by vacuum distillation
A fraction of 5.89 is obtained. The IR spectrum of this product showed absorption at 11000 m-1, suggesting that it was an ether compound, and 1-chloro-1,3-diphenylpropane could not be obtained. Comparative Example 3 A reaction was carried out under exactly the same conditions as in Example 1, except that the metallic iron was changed to 329η (2 mmol) of ferric chloride.

Claims (1)

[Scope of Claims] 1. A method for producing 1-chloro-1,3-diphenylpropane, which comprises reacting benzyl chloride and styrene in the presence of a catalyst consisting of triphenylphosphine and metallic iron. 2. The method for producing 1-chloro-1,3-diphenylpropane according to claim 1, wherein the reaction temperature is 95 to 130°C. 3. 1-chloro-1 according to claim 1, in which the reaction is carried out by adding a solvent that dissolves triphenylphosphine.
, 3-diphenylpropane manufacturing method.