JPS5948815B2 - 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 been well studied in the Friedel-Crafts reaction series for a long time.

For example, α-chloroethylbenzene is a mixture of isobutylene and Zn.
Cl2 catalysis gives the 1:1 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. DLa
h3゛Friedel CraftsandRelate
dRoactions'', vol, 2, Pofu 768
3IntersciencePublishers, I
nc, 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. 5 However, the present inventors have discovered that by using a catalyst consisting of a phosphonium salt and metallic iron, it is possible to carry out the side-by-side reaction between benzyl chloride and styrene that does not proceed with the Friedel-Crafts catalyst, and has developed the present invention. This led us to propose the following.

0 Of the catalyst components in the present invention, phosphoniu+-
In general, [R7R2R8P-R4] C
(R, , R2, R3, R4 are all alkyl groups or aryl groups. −
R')Cl (ph is a phenyl group, R is an alkyl group or an aryl group) is preferred.

Further, the metal iron, which is another catalyst component, is preferably granular and has a smaller particle diameter, and generally iron powder of 20 mesh or less, particularly 200 mesh or less, is preferably used. The mixing ratio of the above catalyst components is generally in the range of 0.1 to 100 mmol of phosphonium salt per 1 milligram atom of metallic iron. When recovering as a complex salt, it is desirable to use both catalyst components in an equimolar ratio. In the reaction system of the present invention, the concentration of the catalyst is 0.001 to 0.0 phosphonium salt per mole of styrene.
A ratio of 5 moles is sufficient, and a higher concentration may be used, but it is not economical, and generally a practical concentration of 0.005 to 3 moles of phosphonium salt per mole of styrene is preferred.

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

In addition, the conditions for the reaction of the present invention are not particularly limited, and may be carried out using conventional equipment and means, generally under normal pressure to pressurization, about 95 to 130°C, preferably 105 to 115°C.
It is carried out in the range of °C. In addition, during the reaction of the present invention, solvents that easily dissolve the phosphonium salt, such as alcohols such as methanol, ethanol, and isopropanol, aprotic polar solvents such as acetonitrile and dimethylformamide, and other solvents such as methyl acetate and ethyl acetate may be added. Therefore, the yield of 1-chloro-1,3-diphenylpropane, which is a 1:1 addition product of benzyl chloride 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 1-(1,3-diarylpropyne) used in neurotropic agents, psychotherapeutic agents, etc. It is suitably used as a raw material for piperazine. Example 1 Benzyl chloride 40d (0.348 mono, styrene 11
．． 4d (0.1 mol) and triphenylbenzylphosphonium chloride [Ph3P1CH, ph
) + Cf777Tflf (2mm monolith and metal iron 112
W9 (2 milligram atoms) was charged into a round bottom flask.

After replacing 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. After cooling, water washing was performed twice to remove catalyst residues and the like.

Next, the reaction solution was distilled under reduced pressure to a boiling point of 134
A fraction of 9.5 g was distilled out at ~135°C/21mlH9.
This was confirmed to be 1-chloro-1,3-diphenylpropane by gas chromatography, infrared ray (IR), and nuclear magnetic resonance (NMR) spectra. The yield from styrene is 41.2 moles? It is. Example 2 Instead of triphenyl besidyl phosphonium chloride in Example 1, triphenyl chloromethyl phosphonium chloride [Ph, P CH, Cl') + Cf7
The reaction was carried out in exactly the same manner as in Example 1, except that 63 mg (2 mm) was used.

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 a phosphonium salt and metal iron. 2 Phosphonium salt derived from triphenylphosphine [ph_3P-R]^+Cl
1-chloro- according to claim 1, which is ^- (ph is a phenyl group, R is an alkyl group or an aryl group)
A method for producing 1,3-diphenylpropane. 3. The method for producing 1-chloro-1,3-diphenylpropane according to claim 1, wherein the metallic iron is iron powder with a particle size of 20 mesh or less. 4. The method for producing 1-chloro-1,3-diphenylpropane according to claim 1, wherein the reaction temperature is 95 to 135°C.