Chapter 21, Problem 21.56AP

Interpretation Introduction

(a)

Interpretation:

The synthesis of given compound from the given starting material is to be stated.

Concept Introduction:

Organolithium compounds can be formed by the reaction of alkyl halides with the lithium in THF. On reaction with copper chloride, alkyl lithium compounds form lithium dialkyl cuperate compounds. Acid chloride when reacts with lithium dialkylcuprate they form ketones.

Answer:

The synthesis of given compound from given starting material is shown below.

Explanation:

The given compound $\text{o-bromotoluene}$ reacts with lithium in presence of THF to form organolithium compound. Organolithium compound when treated with the copper chloride forms alkylcuprate. When lithium alkylcuprate is reacted with butyryl chloride in THF and water, $\text{o-methylbutyrophenone}$ is formed. The synthesis of $\text{o-methylbutyrophenone}$ from $\text{o-bromotoluene}$ is shown below.

Figure 1

Conclusion:

The synthesis of given compound is shown in Figure 1.

Answer to Problem 21.56AP

The synthesis of given compound from given starting material is shown below.

Explanation of Solution

The given compound $\text{o-bromotoluene}$ reacts with lithium in presence of THF to form organolithium compound. Organolithium compound when treated with the copper chloride forms alkylcuprate. When lithium alkylcuprate is reacted with butyryl chloride in THF and water, $\text{o-methylbutyrophenone}$ is formed. The synthesis of $\text{o-methylbutyrophenone}$ from $\text{o-bromotoluene}$ is shown below.

Figure 1

Conclusion

The synthesis of given compound is shown in Figure 1.

Interpretation Introduction

(b)

Interpretation:

The synthesis of given compound from the given starting material is to be stated.

Concept Introduction:

Grignard reagent is formed when alkyl halide compound reacts with magnesium in presence of ether. Potassium dichromate is a strong oxidizing agent. It can easily oxidize alcohol group to carboxylic acid group. The reaction of carboxylic acid with alcohol results in the formation of ester.

Answer to Problem 21.56AP

The synthesis of given compound from given starting material is shown below.

Explanation of Solution

Bromocyclohexane when reacted with magnesium in the ether, it will form grignard reagent. Then grignard reagent will react with epoxide to form $2-\text{cyclohexylethanol}$. In presence of potassium dichromate it will get oxidized to form carboxylic acid derivative. The acid formed will form ethyl ester in ethanol. Ester will react with methyl magnesium bromide followed by hydrolysis to form $\text{1-cyclohexyl-2-methyl-propanol}$.

Figure 2

Conclusion

The synthesis of given compound is shown in Figure 2.

Interpretation Introduction

(c)

Interpretation:

The synthesis of given compound from the given starting material is to be stated.

Concept Introduction:

The carboxylic acid compound reacts with ammonia to form the amide compound. The carbonyl carbon of acid is electrophilic in nature and the lone pair of nitrogen atom of ammonia acts as nucleophile. They will undergo the nucleophilic substitution reaction. Lithium aluminium hydride is a strong reducing agent.

Answer to Problem 21.56AP

The synthesis of given compound from given starting material is shown below.

Explanation of Solution

The phthalic acid reacts with ammonia, the lone pair of ammonia nitrogen attacks the carbonyl carbon atom and then with the removal of water molecule phthalamic acid is formed. Then phthalamic acid undergoes cyclization reaction to form phthalamide. Phthalamide upon reduction with lithium aluminium hydride e form the desired product. The synthesis of the given compound is shown below.

Figure 3

Conclusion

The synthesis of given compound is shown in Figure 3.

Interpretation Introduction

(d)

Interpretation:

The synthesis of given compound from the given starting material is to be stated.

Concept Introduction:

Acid can be converted into acid chloride by the reaction of acid with $\text{SOC}{\text{l}}_{\text{2}}$. The acid chloride thus formed can react with primary amine to form amide. The amide formed upon reduction will form secondary amine. Lithium aluminium hydride is used as reducing agent for reducing amide into secondary amine.

Answer to Problem 21.56AP

The synthesis of given compound from given starting material is shown below.

Explanation of Solution

The isovaleric acid reacts with $\text{SOC}{\text{l}}_{\text{2}}$ to form acid chloride. Acid chloride reacts with aniline to form the amide bond. The lone pair of nitrogen of aniline attacks the electrophilic carbon of acid chloride to form the amide linkage. The compound amide formed will then undergoes reduction in presence of lithium aluminium hydride to form secondary amine $\text{N-phenyl-3-methylbutylamine}$. The synthesis is shown below.

Figure 4

Conclusion

The synthesis of given compound is shown in Figure 4.

Interpretation Introduction

(e)

Interpretation:

The synthesis of given compound from the given starting material is to be stated.

Concept Introduction:

Sodium borohyride is a reducing agent. It reduces the aldehyde group into alcohol functional group. Bromo alkanes can be formed upon reaction of alcohols with hydrogen bromide. Lithium aluminium hydride is used to reduce the nitrile group into the amine group. Amine and acid chloride forms amide on reaction.

Answer to Problem 21.56AP

The synthesis of given compound from given starting material is shown below.

Explanation of Solution

The given starting material reacts with sodium borohydride to convert the carbonyl group into the alcohol group. The reaction of alcohol with hydrogen bromide forms bromoalkene compound. Bromoalkene reacts with the sodium cyanide to form nitrile compound. The nitrile upon reduction forms amine. The amine functional group when reacts with the acid chloride it forms the amide. The synthesis is shown below.

Figure 5

Conclusion

The synthesis of given compound is shown in Figure 5.

Interpretation Introduction

(f)

Interpretation:

The synthesis of given compound from the given starting material is to be stated.

Concept Introduction:

Cyanohydrin can be formed on reaction of ketone with cyanide. It is a nucleophilic addition reaction. The cyanide ion acts as nucleophile and carbonyl carbon is electrophile. Nitrile group can be converted into amine by reduction with lithium aluminium hydride.

Answer to Problem 21.56AP

The synthesis of given compound from given starting material is shown below.

Explanation of Solution

Ketones react with the hydrogen cyanide to form cyanohydrin. The cyanide ion acts as the nucleophile and attacks the electrophilic carbon of the carbonyl group. The cyano hydrin formed will undergo reduction in presence of lithium aluminium hydride to reduce the cyanide group to amine group. The synthesis of the given compound is shown below.

Figure 6

Conclusion

The synthesis of given compound is shown in Figure 6.

Interpretation Introduction

(g)

Interpretation:

The synthesis of given compound from the given starting material is to be stated.

Concept Introduction:

Nitration reaction is the reaction in which nitro derivatives are formed. The mixture of nitric acid and sulfuric acid is used as the nitrating mixture. Benzoic acid upon nitration form meta nitrobenzoic acid. The reaction of carboxylic acid with sodium hydroxide produces sodium salt of carboxylic acid.

Answer to Problem 21.56AP

The synthesis of given compound is shown below.

Explanation of Solution

The benzoic acid undergoes nitration reaction in presence of nitric acid and sulfuric acid. The meta product is formed upon nitration of benzoic acid. The meta-nitrobenzoic acid is formed on nitration of benzoic acid. Sodium salt of benzoic acid is formed when benzoic acid reacts with sodium hydroxide. The reaction between the meta-nitrobenzoic acid and sodium salt of benzoic acid forms the desired product. The synthesis of the given compound is shown below.

Figure 7

Conclusion

The synthesis of given compound is shown in Figure 7.

Interpretation Introduction

(h)

Interpretation:

The synthesis of given compound from the given starting material is to be stated.

Concept Introduction:

Acid can be converted into acid chloride by the reaction of acid with $\text{SOC}{\text{l}}_{\text{2}}$. The acid chloride. Grignard reagent is formed when alkylhalide compound reacts with magnesium in presence of ether. The hydroxy ester compounds form lactones upon ring formation. Hydrogen in presence of inert metal is used as reducing agent, the reduction is known as catalytic reduction.

Answer to Problem 21.56AP

The synthesis of given compound is shown below.

Explanation of Solution

The carboxylic acid group is converted into the acid chloride group by reaction of acid with thionyl chloride. Acid chloride undergoes catalytic reduction to form aldehyde group. Methyl magnesiumbromide converted the product into alkylated secondary alcohol. The formed hydroxy ester compound undergoes cyclization reaction to form the lactone. The synthesis of the given compound is shown below.

Figure 8

Conclusion

The synthesis of given compound is shown in Figure 8.

Interpretation Introduction

(i)

Interpretation:

The synthesis of given compound from the given starting material is to be stated.

Concept Introduction:

Potassium permanganate is a strong oxidizing agent. It will oxidize the alkyl group directly to the carboxylic acid group. Thionyl chloride is used for chlorinating the carboxylic acid group. Acid chloride and amines reacts to form the amide linkage.

Answer to Problem 21.56AP

The synthesis of given compound is shown below.

Explanation of Solution

The compound, $\text{p-methoxytoluene}$ undergoes oxidation reaction with potassium permangnate to form $\text{p-methoxybenzoic}\text{acid}$. The reaction of $\text{p-methoxybenzoic}\text{acid}$ with thionyl chloride forms the acid chloride derivative, which when treated with the excess of methyl amine forms the product. The synthesis of given compound is shown in Figure 9.

Figure 9

Conclusion

The synthesis of given compound is shown in Figure 9.

Interpretation Introduction

(j)

Interpretation:

The synthesis of given compound from the given starting material is to be stated.

Concept Introduction:

Chloro formic esters and carbonates are formed when phosgene reacts with alcohol compounds. The carbon of phosgene is electrophilic in nature. The phosgene reacts with alcohol and amines. Lone pair of oxygen atom in the alcohol compounds acts as the nucleophilie. Thus nucleophilic substitution reaction can occur.

Answer to Problem 21.56AP

The synthesis of given compound is shown below.

Explanation of Solution

Phosgene has an electrophilic carbon centre. The lone pair of oxygen atom of alcohol acts as nucleophile and attacks at the electrophilic carbon of phosgene. Chloride ion acts as the leaving group. The phosgene reacts with methanol to form methyl chloroformate. Then methyl chloroformate reacts with phenol to form the methyl phenyl carbonate. The complete synthesis is shown below.

Figure 10

Conclusion

The synthesis of given organic compound is shown in Figure 10.

Interpretation Introduction

(k)

Interpretation:

The synthesis of given compound from the given starting material is to be stated.

Concept Introduction:

The formation of biaryls by the coupling of aryl halides is known as Ullmann reaction. The reaction takes place in the presence of copper. The reaction proceeds via radical mechanism. The thoinyl chloride reacts with acid to form acid chloride. Potassium permangenate is a strong oxidizing agent which convert alkyl group directly into acid group.

Answer to Problem 21.56AP

The synthesis of given organic compound is shown below.

Explanation of Solution

The $\text{p-bromotoluene}$ reacts with the copper to give oxidative addition product which is aryl copper compound. The reaction proceeds via radical formation. The two aryl copper radicals formed will couple to form biphenyl compound. The compound formed has methyl at para position of both benzene rings, which gets oxidized in presence of potassium permangnate to carboxylic acid group. Acid chloride is formed when acid reacts with the thionyl chloride, which then reacts with lithium dimethylcuperate to form the desired product. The synthesis of given compound is shown below.

Figure 11

Conclusion

The synthesis of given compound is shown in Figure 11.