Ethylmagnesium bromide, reaction with nitriles

Two methods for the preparation of enamides from nitriles are generally used. Reaction of ethylmagnesium bromide with a variety of aromatic nitriles in refluxing ether and subsequent treatment of the suspension of the iminomagnesium bromide with acetyl or benzoyl chloride or with a variety of esters638-640 yielded the enamides in 25-60% yield (equation 44). 

Alkyl and arylmagnesium halides react with 2-methylquinoxaline by addition of one mole of reactant to the 3,4-bond. After hydrolysis the 2-alkyl- or 2-aryl-l,2-dihydro-3-methylquinoxalines (52) are obtained. When ethylmagnesium bromide is used a dimeric by-product (53) is also isolatedReaction of 2,3-dimethylquinoxaline with benzonitrile and lithium amide gives l-amino-l-phenyl-2-(3-methyl-2-quinoxalinyl)-ethylene (54). The mono- and dilithium salts of 2,3-dimethylquinoxaline have been generated from the quinoxaline by reaction with one or two equivalents of lithium diisopropylamide (LiNPr, respectively. These salts have been reacted with a variety of electrophilic reagents such as alkyl halides, aryl ketones, esters, and nitriles. " ... 

The Bradsher reactionl49 jg a synthetic route that converts aryl ketones (234) to polycyclic hydrocarbons such as 235. This reaction can also be applied to heterocyclic derivatives of 234 (X = O, S, Se). A common route to ketones such as 234 is shown for the preparation of 240. Two of the aryl groups are incorporated by a Grignard reaction of aldehyde 236 with phenylmagnesium bromide, producing 237 in 81% yield. Subsequent treatment with cuprous cyanide (also see sec. 2.1 l.E) leads to nitrile 238, and reaction with ethylmagnesium bromide gives the ketone precursor (239). Subsequent reaction with HBr (reflux for four... 

After performing the reaction of ethylmagnesium bromide with butanenitrile, followed by vigorous acid hydrolysis, you analyze your product. Describe differences in the IR spectrum or proton NMR spectrum that would allow you to decide whether your product was an imine, a nitrile, or a ketone. 

Reaction of chloroacetonitrile with 4,5,6,7-indolyl magnesium bromide, obtained by treatment of tetraflnoroindole with ethylmagnesium bromide, proceeded regioselectively at 3-position to afford the corresponding nitrile 177 in moderate yield [58c],... 

Obtained by reaction of ethylmagnesium bromide with 2,3,4-trimethoxybenzo-nitrile (25%) [6973]. 

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