Grignard reagents and nitriles

As we know, the Grignard reagents and nitriles ean be prepared from alkyl halides (refer Unit 10, Class XII). The above methods... 

The interaction of Grignard reagents and nitriles produces ketimines which may be hydrolyzed to ketones without isolation (method 187). 

In addition to the examples above, the 2-position of quinoline-A-oxide has been functionalized through addition of malonate derivatives, Grignard reagents, and nitriles. ... 

Contrary to benzo[b]thiophen, benzo[b]selenophen is acylated at position 2. 2-Bromobenzo[b]selenophen, prepared from the 2-lithium derivative and bromine, is acylated at position 3, and from this derivative the 3-isomers could be synthesized. A large number of 2- and 3-aroylbenzo[b]seleno-phens were synthesized, either by Friedel-Crafts reaction of benzo-[bjselenophencarboxylic acid chlorides and benzenes or from benzol bjselenophens and benzoic acid chlorides. Also the reaction between Grignard reagents and nitriles was used for the synthesis of aroylbenzo[b]selenophens. 4,S-Diaminobenzo[b]selenophen has been synthesized via nitration of 5-aminobenzo[b]selenophen or via the reaction of the diazonium salt derived from the S-amino-derivative with p-sulphanilic acid. From the diamino-derivative, several fused benzo[b]selenophens, e.g. (525), (526), and (527), were prepared. Reaction of the phenyl-... 

Among the methods for preparing carboxylic acids carboxylation of a Grignard reagent and preparation and hydrolysis of a nitrile convert RBr to RCO2H The malonic ester synthesis converts RBr to RCH2CO2H... 

The conversion of a nitrile R —CN into a ketone R —CO—R demonstrates that polarized multiple bonds other than C=0 also react with Grignard reagents, and that such reactions are synthetically useful. Esters 22 and acid chlorides can react subsequently with two equivalents of RMgX the initially formed tetravalent product from the first addition reaction can decompose to a ketone that is still reactive, and reacts with a second RMgX. The final product 23 then contains two substituents R, coming from the Grignard reagent ... 

A ketone results from the reaction between a Grignard reagent and a nitrile, with the C=N carbon of the nitrile becoming the carbonyl carbon. Identify the two groups attached to the carbonyl carbon atom in the product. One will come from the Grignard reagent, and the other will come from the nitrile. 

We have attempted the low temperature formation of Grignard reagents containing nitrile, ketone and ester functional groups. These reactions were largely unsuccessful, except in the case of 8-bromooctanenitrile. 

Early attempts to convert aliphatic nitriles into primary cyclopropylamines, in the same way as N,N-dialkylcarboxamides 44 are transformed to N,N-dialkylcyclopropylamines 47 under the action of Grignard reagents and Ti(OiPr)4, were unfruitful [136], However, Szymoniak et al. have found that the addition of a Lewis acid such as boron trifluoride etherate is necessary to activate azatitanacyclopentene 153 resulting from insertion of... 

Halogenopyridines can undergo metal-halogen exchange when treated with butyllithium. The lithium derivatives then behave in a similar manner to arylithiums and Grignard reagents and react with electrophiles such as aldehydes, ketones and nitriles (Scheme 2.17). Thus, aldehydes and ketones form alcohols, and nitriles yield A -lithioimines, which on hydrolysis are converted into pyridyl ketones. 

Carboxylic acids are prepared by at least four methods (1) by oxidation of primary alcohols or aldehydes, (2) by oxidation of an aromatic side chain, (3) from a Grignard reagent and carbon dioxide, or (4) by hydrolysis of a nitrile, RC=N. 

The Addition of Grignard Reagents to Nitriles and Isocyanates Alkyl,oxo-de-nitrilo-tersubstitution (Overall transformation)... 

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