Process for the preparation of benzyl-metal compounds and proces

Chemistry of carbon compounds – Miscellaneous organic carbon compounds – C-metal

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

585452, 585453, 568626, C07F 100, C07F 102, C07F 104, C07F 106

Patent

active

060248971

DESCRIPTION:

BRIEF SUMMARY
TECHNICAL FIELD

The present invention relates to a method of preparing benzyl metal compounds that are useful as a synthetic intermediate.
Further, the present invention relates to a novel method of preparing 4-phenyl-1-butenes that are useful as a synthetic intermediate of agricultural chemicals and medicines. More specifically, the present invention relates to a method of preparing 4-phenyl-1-butenes, in which the above-described method of preparing benzyl metal compounds is used.


BACKGROUND ART

Benzyl metal compounds are important synthetic intermediates for construction of a carbon skeleton. Hitherto, there are many known synthesis methods of such compounds, as exemplified below. (1) A method in which a benzyl ether is reacted with lithium, to give benzyl lithium (J. Org. Chem., 26, 3723 (1961)); (2) A method in which benzyl halides are reacted with metal zinc or cadmium, to give benzyl zinc halides or benzyl cadmium halides (Compt. Rend., 245, 2054 (1957)); (3) A method in which, first, a Grignard reagent prepared from benzyl halides and metal magnesium is converted to a benzyl mercury compound or a benzyl tin compound, and then the resultant compound is treated with an alkyl lithium, to give benzyl lithium (J. Organomet. Chem., 2, 431 (1964)); (4) A method in which toluene is reacted with an alkyl lithium, in the presence of a specific ligand (Organometallics, 4, 2117 (1985)); (5) A method in which an alkyl lithium compound is reacted with another metal alkoxide, and then the resultant alkyl metal compound is reacted with toluene (Angew. Chem. Int. Ed. Engl., 32, 1501 (1993)); (6) A method in which phenyl sodium is reacted with toluene, under heat reflux (J. Am. Chem. Soc., 62, 1514 (1940)); (7) A method in which phenyl sodium is reacted with toluene, in the presence of tetrahydrofuran, at room temperature (JP-A-48-75551 ("JP-A" means unexamined published Japanese patent application)).
However, all of these methods have some respective problems. That is, in the method (1), only 1 equivalent of benzyl lithium can be generated from 2 equivalents of expensive lithium. In the method (2), the yield is low. The route of the method (3), via a benzyl mercury compound or a benzyl tin compound, is to remove dibenzyl (Wurtz coupling product), which is a by-product at the Grignard reaction, but the method (3) cannot be used in industrial production because harmful heavy metal wastes are discharged. The methods (4) and (5) are not economically profitable, because an expensive alkyl lithium compound is used, and moreover it is necessary to add a ligand that is used to accelerate the reaction, in an amount of not less than 1 equivalent. In the method (6), the reaction of phenyl sodium with toluene is so slow at room temperature that the operation of heat reflux is necessary, as well as that the heat reflux also causes the problem that tar is generated due to thermal decomposition of phenyl sodium. The method (7) was developed to attempt to overcome the drawbacks of the method (6). Consequently the method (7) has an advantage that the reaction can be carried out at room temperature, but actually this method is not suitable for industrial production, from a viewpoint of separation and recovery of a solvent, because it is necessary to add water-soluble tetrahydrofuran to phenyl sodium, in an amount of 20 to 300 wt % based on phenyl sodium.
On the other hand, examples of a method of preparing 4-phenyl-1-butenes include (a) a method in which benzyl magnesium halides are reacted with allyl halides (e.g. J. Am. Chem. Soc., 55, 699 (1933)), (b) a method in which allyl magnesium halides are reacted with benzyl halides (e.g. Bull. Soc. Chim. Fr., 43, 1326 (1928)), (c) a method in which phosphorusylides are reacted with carbonyl compounds according to the Wittig reaction (e.g. JP-A-3-294271), (d) a method in which phenethyl magnesium halides are reacted with vinyl halides, in the presence of a nickel catalyst (e.g. U.S. Pat. No. 5,030,784), and (e) a method in which allyl halides are reacted with benzyl sodium that was ob

REFERENCES:
patent: 3953535 (1976-04-01), Shima et al.
patent: 4006187 (1977-02-01), Kamienski et al.
patent: 4018840 (1977-04-01), Iwata et al.
patent: 4084061 (1978-04-01), Kanazawa et al.
patent: 4155942 (1979-05-01), Hara et al.
patent: 4709109 (1987-11-01), Sperling et al.
patent: 5030784 (1991-07-01), Slaugh
patent: 5329058 (1994-07-01), Shimada et al.
patent: 5523504 (1996-06-01), Itoh
patent: 5659097 (1997-08-01), Fushimi et al.
J. Chem. Soc., 1975 -1979(1950).
J. Org. Chem., 26:3723-3729 (1961).
J. Oranomet. Chem., 2:431-433 (1964).
Organometallics, 4: 2117-2121 (1985).
Angew. Chem. Int. Ed. Engl., 32:1501-1523 (1993).
J. Am. Chem. Soc., 62:1514-1519 (1940).
J. Am. Chem. Soc., 55, 699-702 (1933).

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Process for the preparation of benzyl-metal compounds and proces does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Process for the preparation of benzyl-metal compounds and proces, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for the preparation of benzyl-metal compounds and proces will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-1903238

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.