Solvents diethoxymethane

When bidentate solvents are present, the clusters may crystallize forming linear polymers by linking clusters together, as in complexes 292-295. This further diminishes solubility and reactivity of the alkyllithium compound, making the unassociated RLi species the most probable reactive form in synthetic processes. MeLi dissolved in diethoxymethane shows at room temperature a single Li NMR peak, that resolves into four distinct peaks at —80°C, pointing to temperature-dependent monomer/oligomer/polymer equilibria . 

When starting from ( )-l-o-bromophenyl-2-trimethylsilylethene 31 [30] the postulated trilithium compound 26 is obtained by addition of lithium metal to 32 in this case diethoxymethane (DEM) [31] is the most suitable solvent. Compound 26, however, eliminates lithium hydride very easily, so only a small amount (7 %) of the trimethyl derivatives (erythro and threo 33, 1 4) is obtained. As the main product 28 (66 % yield) is again observed, additionally 9 % of ( )-l-o-tolyl-2-trimethylsilylethene originating from 32 is found (Scheme 7). 

Diethoxymethane (DEM), an acetal with solubility similar to etheric solvents, may be a good substitute forTHF and EtzO [14]. DEM has a low propensity to form peroxides and can be used for Grignard reactions and organolithium reactions. Methyl lithium is available as a solution in DEM, which is much safer than CH3Li solutions in Et20 [15]. 

Venepalli, B., Diethoxymethane (DEM) as a Versatile Process Solvent and Reagent in Organic... 

Researchers from Merck elaborated a convergent synthesis for the AT II antagonist losartan 30 with the key biaryl coupling step in the final stage of the protocol [100]. The two reaction partners 28 and 29 were coupled very efficiently (99% yield) utilizing 1 mol% of palladium(II) acetate and 4 mol% triphenylphosphine. As the solvent, a 1 4 mixture of THF and diethoxymethane containing a defined amount of water was crucial for the high reaction rates and yields. 

Bromochloromethane Diethoxymethane solvent, reaction/diluent pesticides Butyrolactone solvent, reaction aerosols Methylal... 

Diethoxymethane (DEM) is offered by Eastman Chemical Company as a cost-effective replacement solvent for monoglyme (1,2-dimethoxyethane) and methylal. The DEM diether is stable under alkaline conditions, but can be... 

Venepalli, B. R., Diethoxymethane (DEM) a Versatile Process Solvent and Unique Reagent in Organic Synthesis, presented at Chemical Specialities USA 94 Symposium. A copy of the paper is available from Eastman Chemical Company, 1-800-EASTMAN, ext. 1480. 

These include chloroethylene carbonate (Cl-EC), vinylene carbonate (VC), ethylene sulfite (ES), propylene sulfite (PS), fluoroethylene sulfite (EEC), a-bromo-y-butyrolactone, methyl chloroformate, f-butylene carbonate (f-BC), and 12-crown (12-C-4). In addition to these additives, co-solvents, such as dimethylsulfoxide (DMSO), diethoxymethane (DEM), dimethoxymethane (DMM), and diethoxyethane (DEE) are also effective for stable SEI formation in PC-based solutions. The molecular structures of these additives and co-solvents are summarized in Figure 13. It seems that all these additives give stable SEI layers on graphite surface ... 

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