: �����, 1996. - �. This application claims priority from DE 102004043501.4 filed Sep.6,2004, herein incorporated by reference in its entirety. Privacy Policy for more information. Accordingly, documents EP-A 02 285 374 and U.S. Pat. You can easily unsubscribe at any time. Methyllithium is available commercially in the form of an approximately 5% solution in diethyl ether or in the form of an approximately 6% solution in diethyl ether, which contains approximately 10% lithium bromide as complex-forming stabiliser. Synthesis agent containing dissolved methyllithium. In this manner, methyllithium-lithium bromide-containing solutions (synthesis agents) having a very high LiBr concentration can be obtained in a particularly simple and economical manner. *Items available in Japan warehouse will be dispatched within 2-3 calendar weeks upon orders. In a further preferred embodiment, the lithium metal is used in the form of relatively coarse pieces, for example in the form of granules having edge lengths of at least 1 mm. This procedure has the advantage that the filtration is substantially more simple compared with the process in which methyl chloride is used. - �.1, ��.1. lithium bromide Physical appearance: colorless cubic crystals Empirical formula (Hill's system for organic substances): BrLi Structural formula as text: LiBr Molar/atomic mass: 86.85 Melting point (°C): 549 Boiling point (°C): 1310 Solubility (g/100 g of solvent): amyl alcohol: soluble acetone: 18.2 (20°C) acetone: 39.7 (60°C) 1. Lithium borohydride is renowned as one of the highest energy density chemical energy carriers.Although presently of no practical importance, the solid will liberate 65 MJ/kg heat upon treatment with atmospheric oxygen. For example, the enantiomeric excess (ee) in the asymmetric protonation of prochiral enolates is affected by lithium salt additives (A. Yanagisawa et al., Synlett 1998, 174-176): The object of the present invention is to overcome the disadvantages of the prior art and, in particular, to provide synthesis mixtures containing methyllithium in a solvent that is better to handle than diethyl ether, which synthesis mixtures have a highly selective action. wherein R1 and R2 independently of one another are H, methyl (Me) or ethyl (Et), and R3 and R4 are Me or Et, the molar ratio of LiBr to MeLi being at least 0.7 and not more than 1.5 and the methyllithium concentration being at least 4 wt. Privacy Policy In Example 3, a solution containing 7.2% MeLi and 8.25% lithium bromide is described. However, because these solutions tend to decompose by metallation of the aromatic hydrocarbon, dialkylmagnesium compounds are added. The formation and reaction of Grignard reagents in MeTHF and THF are similar. - pp. 898-900, ������� ���������� ��������: �������������� ���������� ��������� I-IV �����. Industrial and Engineering Chemistry Research. Subscribe above to receive our eNews, featuring scientific research, new products, and exclusive promotions. Methyllithium is used as a reagent in the production of pharmaceutical products, such as vitamins or steroids, and in special synthesis steps, such as reactions of the carbene type for the preparation of allenes and alkoxycyclopropanes, methylating reactions for the preparation of alkenyllithium and steroidal alkenyl compounds, reduction reactions of various transition metal halides, such as PdCl2 to Pd(0), the preparation of methyllithium cuprates for 1,4-conjugated additions or for the preparation of other organometallic compounds, such as Me2Mg, MeTi(NEt2)3, Me3Al, Me3Al, Me3As or Me3Ga. EP 753 520 further provides for the addition of up to 10% lithium bromide or lithium iodide in order to obtain a special synthesis agent suitable for stereochemical reactions. *INR price is exclusive of domestic taxes applicable. The invention relates to a synthesis agent containing methyllithium/lithium bromide, and to a process for the preparation thereof. From EP 753 520 there are also known synthesis agents containing dissolved methyllithium, which synthesis agents contain methyllithium in a solvent of the general formula: wherein R1 and R2 independently of one another are H, methyl (Me) or ethyl (Et) and R3 and R4 are methyl or ethyl. - pp. A sample of the clear phase was taken and analysed as follows: The following solution composition is calculated therefrom: 5.5⁢⁢wt.⁢%⁢⁢methyllithium16.9⁢⁢wt.⁢%⁢⁢lithium⁢⁢bromide0.4⁢⁢wt.⁢%⁢⁢lithium⁢⁢chloride}⁢molar⁢⁢ratio⁢⁢LiBr⁢:⁢MeLi=0.78⁢:⁢1 Remainder⁢:⁢⁢DEM. - pp. %. You can change or update your cookiesettings at any time. 25, �������� �.�. - pp. P501 : Dispose of contents/ container to an approved waste disposal plant. • If your information is correct and you are still not able to view the requested SDS,  21. These commercial forms of methyllithium in diethyl ether have only limited usability owing to the low flash point of diethyl ether. - �. 2-Methyltetrahydrofuran (MeTHF) is a commercially available solvent that is produced from renewable resources. As in Example 1, 74.5 g of a bromide-free, 8.0% methyllithium solution in DEM, 23.7 g of lithium bromide and 52 g of anhydrous DEM were mixed and stirred for two hours at room temperature. & Terms of Use. 108-109, ����� � ���������� ������ � ���������� ���������. ), and 1.5 mol/L THF solution of LiBr (500 µL). - pp. for more assistance. L. Anderson, M. Neurock, S. D. Minteer, P. S. Baran, Metal Compounds [Chemical Structural Class], Typical Metal Compounds [Chemical Structural Class], Li (Lithium) Compounds [Chemical Structural Class]. Final weighed product: 362 g of a yellow, slightly cloudy and viscous solution, Product composition: 6.3% MeLi, 24.7% LiBr, remainder DEM. In the same apparatus as in Example 3, 17.2 g (2.48 mol.) In hydrocarbons and aromatic compounds, on the other hand, methyllithium is insoluble. This means that, in the case where the amount of LiBr necessary to achieve a LiBr:MeLi stoichiometry has not already been introduced with the reaction solvent, the required amount of LiBr is added after the reaction and before or after separation of the insoluble constituents (unreacted lithium metal and insoluble lithium halide). of methyl bromide gas were passed in in the course of 5.5 hours and at internal temperatures of from 10 to 15° C. When the metered addition was complete, stirring was continued for 2 hours at room temperature and the suspension was then discharged onto a D1 glass filter frit. %) and in a molar ratio LiBr:MeLi >>0.29, so that, after completion of the reaction according to the above equation, it cannot even be filtered off, as described in EP 753 520. - pp. *Upon orders receipt, Hyderabad stocks will be dispatched on the same day & Chennai stocks on next working day.


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