Ethyl magnesium bromide, reaction with

A method for generating a perfluoroarylmagnesium compound is the cleavage of a pentafluorophenyl-metal bond by a nucleophile such as ethyltnagnesium bromide As an example, tetrakis(pentafluorophenyl)tin on reaction with ethyl-magnesium bromide gives a series of products, one of which may result from pentafluorophenylmagnesium bromide [27] (equation 7)... 

Phenylacetone, 54, 50 Phenylacetonitrile, 50, 20 Phenylacetylene, reaction with ethyl magnesium bromide,... 

Muller [76] has described a gas chromatographic method for the determination of tributyltin compounds in sediments. The tributyltin compounds are first converted to tributylmethyltin by reaction with ethyl magnesium bromide, and then analysed using capillary gas chromatography with flame photometric detection and gas chromatography-mass spectrometry. Tributyltin was found in samples of sediment and these results demonstrated that the technique has detection limits of less than 0.5pg L 1. 

Now let s draw the forward scheme. Dehydration of the amide with thionyl chloride produces a nitrile. Subsequent reaction with ethyl magnesium bromide, followed by aqueous acidic work-up, yields 3-pentanone, which can be converted to the desired enamine via an acid-catalyzed reaction with dimethylamine, as shown. 

Write the equation for the reaction of 1 hexyne with ethyl magnesium bromide as if it involved ethyl anion (CH3CH2 ) instead of CH3CH2MgBr and use curved arrows to represent the flow of electrons j... 

The interpretation put forward is not entirely satisfactory since the reaction does not seem to be dangerous when it is carried out with ethyl magnesium bromide. 

Tuulmets [Kinetics and Catalysis, 5 (59), 1964] has studied the kinetics of the reaction of ethyl magnesium bromide with pinacolin. He used a calorimetric technique to monitor the progress of the reaction. The overall temperature increase of the reaction mixture was less than a degree. Mixture temperatures were determined with a sensitive potentiometer. The data below... 

More recently, Polish chemists have reported a synthesis of both aryl and aliphatic secondary nitramines by treating amine substrates with ethyl magnesium bromide followed by reaction with n-butyl nitrate (Equation 5.8). This method, which uses nonpolar solvents like hexane or benzene, has been used to synthesize aliphatic secondary nitramines, and At-nitro-A-methylanilines which otherwise undergo facile Bamberger rearrangement in the presence of acid. The direct nitration of At-unsubstituted arylamines usually requires the presence of an electron-withdrawing group. Reactions are retarded and yields are low for sterically hindered amines. 

More conclusive evidence for the intermediacy of benzocyclopropenyl cations was obtained upon chloride/fluoride exchange of 22 with AgF in acetonitrile, which led to the chloro-fluoro derivative 278 and, ultimately, to the difluoro compound 279 in almost quantitative yield. Reaction of 22 with LiAlH AlClj afforded 2,5-diphenylbenzocyclopropene (264), while that with ethyl magnesium bromide lead to the diethyl derivative 280. Phenylmagnesium bromide and methylmagne-... 

The reaction of 2-acetylphenothiazine with ethyl magnesium bromide led to 2-(but-2-enyl)phenothiazine (156) A-substituted ketones gave ethynyl derivatives (157) on treatment with acetylene. Reduction of 2-acyl derivatives to alcohols has been performed by the Meerwein-Ponndorf reaction and by using LiAlH. - - Polarographic one-electron reduction of the keto group in 10-acetyl-2-()3-piperidinopropionyl)phenothiazine has been reported. ... 

Synthetic uses. Arens,° in reviewing the many reactions of ethynyl ethers and thioethers, states that the first use of ethoxyacetylene for the synthesis of a,/3-unsaturated aldehydes was described in a paper published in Russia in 1945, but that the paper was abstracted incorrectly and remained unknown in the western world, van Dorp and Arens" rediscovered the method and in 1947 described its use in the synthesis of vitamin A aldehyde. Ethoxyacetylene is treated with ethyl-magnesium bromide to form the Orignard reagent, and this is added to the carbonyl group of the "C lii-kelone" to produce the acetylenic cnrbinol (I). Semlhydrogenation... 

Methylenedioxyphenol in ethereal solution by conversion with ethyl magnesium bromide to the ethoxymagnesio derivative at ambient temperature and removal of solvent and its replacement with toluene, was acylated with cinnamoyl chloride by dropwise introduction of a toluene solution of the acid chloride and reaction at ambient temperature for 5 hours following which work-up by quenching with ammonium chloride solution, gave 2-hydroxy-4,5-methylenedioxychalcone in 70% yield (ref.32). 

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