Chemistry of hydrocarbon compounds – Unsaturated compound synthesis – From nonhydrocarbon feed
Patent
1995-09-05
1998-03-03
Wood, Elizabeth D.
Chemistry of hydrocarbon compounds
Unsaturated compound synthesis
From nonhydrocarbon feed
585639, 585641, C07C 132
Patent
active
057237140
DESCRIPTION:
BRIEF SUMMARY
CROSS-REFERENCES TO RELATED APPLICATIONS
This application has been filed under 35 U.S.C. 371 from International Application No. PCT/EP94/03231, which was filed on Sep. 28, 1994, and published as WO 95/09826, on Apr. 13, 1995.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The object of the invention is a novel process for the production of methylenecyclopropane from 3-halogen-2-methyl-1-propene (.beta.-methallyl halogenide).
2. Description of Related Art
Methylenecyclopropane is a highly reactive reagent which can be used in many cases in the organic synthesis. For instance, cyclopropylamines can be produced thereof, which reinforce as special substituent the activity of different pharmaceuticals. The (3+2) cycloadditions with alkenes, catalyzed by transition metals, are resulting in methylene-cyclopentane derivatives, which can be used on their part by appropriate substitution as starting materials for the synthesis of natural products (P. Binger, H. M. Buch, Top. Cur. Chem. 1987, 135, 77; B. M. Trost Angew. Chem. 1986, 98,1; B. M. Trost, Sciences 1991, 1471).
A variety of processes for the production of methylenecyclopropane are already known from the state of the art. Among the variety of methods for the production of methylenecyclopropane (P. Binger, H. M. Buch, Top. Cur. Chem. 1987, 135, 79-151; T. Tsuji, S. Nishida in Patai (Ed. Z. Rappoport) The Chemistry of Cyclopropylgroup; John Wiley, New York 1987, p. 315) the reaction of .beta.-methallylchloride with sodium and potassiumamide reaction of .beta.-methallylchloride with sodium and potassiumamide is outstanding due to its simplicity. This method, originally developed for the preparation of 1-methylcyclopropene (F. Fischer, D. E. Applequist, J. Org. Chem. 1965, 30, 2089) can be used for the preparation of methylenecyclopropane, if higher boiling ethers (dioxane, di-butylether) are used instead of THF as solvents at their boiling points. By using sodium amide, a mixture of methylenecyclopropane and 1-methylcyclopropene is then obtained from .beta.-methallylchloride in a ratio of 4:1 and in a yield of maximally 75%, which will be transferred in a second reaction step by means of potassium tert.-butylate in DMSO into methylenecyclopropane in a yield of 98%. (Total yield of methylenecyclopropane is 70% (R. Koster, S. Arora, P. Binger, Synthesis, 6, 1971, 322-323; R. Koster, S. Arora, P. Binger, Liebigs Ann. Chem. 1973, 1219-1235). The use of potassium amide has the advantage, that the methylenecyclopropane can be obtained directly in a purity of 94-97%, however, the yield is then decreasing to 36% in boiling THF (R. Koster, S. Arora, P. Binger, Angew. Chem. 1969, 81, 186), to 61% in boiling di-butylether (R. Koster, S. Arora, P. Binger, Liebigs ann. Chem. 1973, 1219-1235).
Pure methylenecyclopropane can also be obtained in boiling THF with a mixture of the bases sodium amide/sodium-tert.-butylate in a ratio of 3:1 in a yield of 43%, however, this mixture of bases has to be employed in an excess of 4,5 (P. Caubere, G. Coudet, Bull. Soc. Chem. FR. 1971, 2234; J. R. Salaun, J. Champion, J. M. Conia, Org. Synth. 57, 1977, 36-40).
The disadvantage of all these process variations is, that one has to work in a heterogeneous system, since sodium amide and potassium amide are not soluble in the afore mentioned solvents. This excludes a production of methylenecyclopropane in an industrial scale, because working with solid sodium amide and potassium amide, respectively, is not acceptable for security reasons.
Therefore, the aim of the invention is an improved process for the production of methylenecyclopropane in an industrial scale, which overcomes the afore mentioned disadvantages of the state of the art.
SUMMARY OF THE INVENTION
It has been found now, that methylenecyclopropane can be prepared also in an industrial scale from .beta.-methallylchloride in solution, and therefore without danger, by using alkali metal-bis-(trialkylsilyl)-amides as bases, particularly those with sodium or potassium as alkali metals. A further advantage of this novel me
Studiengesellschaft Kohle MBH
Wood Elizabeth D.
LandOfFree
Process for the preparation of methylenecyclopropane 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 methylenecyclopropane, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for the preparation of methylenecyclopropane will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2250066