Chapter 22, Problem 22.35P

Interpretation Introduction

(a)

Interpretation: The reagents required to convert phenylacetonitrile $\left({\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}\text{CN}\right)$ to ${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}{\text{COCH}}_3$ are to be stated.

Concept introduction: Grignard reagents are organometallic compounds having the general formula $\text{RMgX}$ where R can be an alkyl or aryl group and X is a halogen atom.

Answer to Problem 22.35P

The reagents required to convert phenylacetonitrile $\left({\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}\text{CN}\right)$ to ${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}{\text{COCH}}_3$ are shown below:

Explanation of Solution

Grignard reagents converts nitriles to corresponding carbonyl groups. ${\text{CH}}_{\text{3}}\text{MgCl}$ can be used to convert phenylacetonitrile $\left({\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}\text{CN}\right)$ to ${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}{\text{COCH}}_3$ as depicted below.

Figure 1

Conclusion

The reagents required to convert phenylacetonitrile $\left({\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}\text{CN}\right)$ to ${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}{\text{COCH}}_3$ are shown in Figure 1.

Interpretation Introduction

(b)

Interpretation: The reagents required to convert phenylacetonitrile $\left({\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}\text{CN}\right)$ to ${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}\text{COC}{\left({\text{CH}}_3\right)}_3$ are to be stated.

Concept introduction: Grignard reagents are organometallic compounds having the general formula $\text{RMgX}$ where R can be an alkyl or aryl group and X is a halogen atom.

Answer to Problem 22.35P

The reagents required to convert phenylacetonitrile $\left({\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}\text{CN}\right)$ to ${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}\text{COC}{\left({\text{CH}}_3\right)}_3$ are shown below:

Explanation of Solution

Grignard reagents converts nitriles to corresponding carbonyl groups. ${\left({\text{CH}}_{\text{3}}\right)}_{\text{3}}\text{CMgCl}$ can be used to convert phenylacetonitrile $\left({\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}\text{CN}\right)$ to ${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}\text{COC}{\left({\text{CH}}_3\right)}_3$ as depicted

Figure 2

Conclusion

The reagents required to convert phenylacetonitrile $\left({\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}\text{CN}\right)$ to ${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}\text{COC}{\left({\text{CH}}_3\right)}_3$ are shown in Figure 2.

Interpretation Introduction

(c)

Interpretation: The reagents required to convert phenylacetonitrile $\left({\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}\text{CN}\right)$ to ${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}\text{CHO}$ are to be stated.

Concept introduction: Nitrile groups get converted to carbonyl group in presence of reducing agents like DIBAL-H.

Answer to Problem 22.35P

The reagents required to convert phenylacetonitrile $\left({\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}\text{CN}\right)$ to ${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}\text{CHO}$ are shown below:

Explanation of Solution

Diisobutylaluminiumhydride(DIBAL-H) is a selective reducing agent. It readily converts nitriles to carbonyl group. DIBAL-H can be used to convert phenylacetonitrile $\left({\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}\text{CN}\right)$ to ${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}\text{CHO}$ as depicted below.

Figure 3

Conclusion

The reagents required to convert phenylacetonitrile $\left({\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}\text{CN}\right)$ to ${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}\text{CHO}$ are shown in Figure 3.

Interpretation Introduction

(d)

Interpretation: The reagents required to convert phenylacetonitrile $\left({\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}\text{CN}\right)$ to ${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}\text{COOH}$ are to be stated.

Concept introduction: Hydrolysis of nitriles in acidic medium convert them to the corresponding carboxylic acids.

Answer to Problem 22.35P

The reagents required to convert phenylacetonitrile $\left({\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}\text{CN}\right)$ to ${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}\text{COOH}$ are shown below:

Explanation of Solution

Acidic hydrolysis of phenylacetonitrile $\left({\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}\text{CN}\right)$ converts it to ${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}\text{CHO}$ as depicted below.

Figure 4

Conclusion

The reagents required to convert phenylacetonitrile $\left({\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}\text{CN}\right)$ to ${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{CH}}_{\text{2}}\text{COOH}$ are shown in Figure 4.