Application of Grignard Reagent: Grignard reagent is a useful intermediate reagent in organic chemistry. The Grignard reaction is an organo-metallic chemical reaction in which alkyl, vinyl, or aryl-magnesium halides add to a carbonyl group in an aldehyde or ketone. By this reagent alkanes, alcohol, aldehydes, ketones, carboxylic acid could be prepared.
(i) Synthesis of hydrocarbon: Being hydrolyzed by water Griganard reagent forms hydrocarbons.
RMgX + H2O → R – H + Mg (OH) X
Example: CH3MgI + H2O → CH4 + Mg (OH) I
(ii) Synthesis of alcohol: Grignard reagent reacts with different carbonyl compounds forming unstable transition stage of compound which by hydrolysis forms different alcohols. The Grignard Reaction is the addition of an organo-magnesium halide (Grignard reagent) to a ketone or aldehyde, to form a tertiary or secondary alcohol, respectively. The reaction with formaldehyde leads to a primary alcohol.
When methanal reacts with Grignard reagent, it forms primary alcohol. In case of other aldehydes, secondary alcohols are formed. In case of ketones, tertiary alcohols are formed.