Question

what is grignard reagent

Answer 1

R-MgX is known as the Grignard reagent 

Answer 2

"Preparation of Grignard reagent . Grignard reagents from via the reaction of an alkyl or aryl halide with magnesium metal. The reaction is conducted by adding the organic halide to a suspension of magnesium in an etherial solvent , which provides ligends required to stabilize the organomagnesium compound."