Question

Bromobenzene is converted to a compound with a molecular formula c7h7br in the reaction scheme below. Draw the structures of the product and the two intermediates, and identify the reagents in each of the three steps.

Bromobenzene is converted to a compound with a molecular formula c7h7br in the reaction scheme below. Draw the structures of the product and the two intermediates, and identify the reagents in each of the three steps.

Answer 1

Concepts and reason

Molecular formula represents a total number of atoms present in the structure. Reagents are the substance used to transform one substance to another. It is also used to transform a functional group of a compound. From the starting material, the reaction undergoes a series of steps such as the formation of Grignard reagent, nucleophilic addition, and nucleophilic substitution to attain a final product.

Fundamentals

The reagents play a vital role in a reaction to undergo a transformation. Each reagent plays a different role in the chemical reaction.

Grignard reagent: Grignard reagent $\left( {{\rm{R - Mg - X}}} \right)$ . R represents an alkyl group or aryl group. X represents halides $\left( {{\rm{I, Br, Cl}}} \right)$ . The main purpose of a Grignard reagent is the formation of new ${\rm{C}}\,{\rm{ - }}\,{\rm{C}}$ bond. Grignard reagent undergoes reaction with carbonyl groups (like ketone ( ${\rm{ - C = O}}$ ), Aldehyde ( ${\rm{ - C( = O)H}}$ ), Ester ( ${\rm{ - C( = O)OR}}$ )) to form an addition product.

Nucleophilic addition: the addition of nucleophile (electron rich) with electrophiles (electron deficient). In this reaction, the double bond is converted to a single bond.

Nucleophilic substitution: In this, the Nucleophile (electron rich) forms a bond with an electrophile (electron deficient) and replaces the leaving group.

The reaction is:

The reaction is:

Mechanism:

The reaction is:

Mechanism:

Ans: