[Maximum number: 4]

Potassium iodide, KI, is used as a reagent in both inorganic and organic chemistry.

(a)

$\quad \mathrm{KI}$ is used as a source of $\mathrm{I}^{-}$ ions in organic synthesis.

One example of this is shown in the synthetic route in Fig. 1.1.

Fig. 1.1

[ 4 ]

(i)

Identify the reagents required for steps 1 and 2 .
step 1
step 2

[ 2 ]

(ii)

Step 3 occurs in two stages.
stage I $\mathrm{NaNO}_{2}$ and HCl undergo an acid-base reaction to produce $\mathrm{HNO}_{2}$ .
stage II $\mathrm{HNO}_{2}$ reacts with $\mathbf{C}, \mathrm{C}_{6} \mathrm{H}_{5} \mathrm{NH}_{2}$ , to produce $\mathbf{D}, \mathrm{C}_{6} \mathrm{H}_{5} \mathrm{~N}_{2}{ }^{+}$ .
Complete the equations for stage I and for stage II.

stage I $\mathrm{NaNO}_{2}+\mathrm{HCl} \rightarrow$

stage II

[ 2 ]

(a)

Amino acids such as alanine are essential building blocks for making proteins. They can be synthesised by a general reaction of which the following is an example.

[ 2 ]

(i)

Suggest the structure of the intermediate compound E by drawing its structural formula in the box above.

(ii)

Suggest, in the box below, the structural formula of the starting material needed to synthesise phenylalanine by the above general reaction.

[ 2 ]

(a)

Methyl orange can be synthesised as shown.

step 1

R
step 2
$\underbrace{\text { S } \mathrm{H}_{3} \mathrm{C}}_{\begin{array}{c}\text { S } \\ \text { methyl orange }\end{array}}$

[ 5 ]

(i)

Deduce the identities of compounds R and S and draw their structures in the boxes.

[ 2 ]

(ii)

Suggest reagents and conditions for step 1 and step 2.
step 1
step 2

[ 3 ]

(a)

(i)

Ammonia, ethylamine and phenylamine, $\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{NH}_{2}$ , are three nitrogen-containing bases.

Place these three compounds in order of basicity, with the most basic first.

(ii)

Explain why you have placed the three compounds in this order.

[ 4 ]

(b)

Phenylamine can be converted to 4 -nitrophenol by the following steps.

[ 5 ]

(i)

Suggest the identity of intermediate B by drawing its structure in the box above.

(ii)

Suggest reagents and conditions for the three steps in the above scheme.

[ 5 ]

(a)

Compare the relative basicities of ammonia, phenylamine and compound H. Explain your answer.

[ 2 ]

[Maximum number: 3]

Nitrobenzene, $\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{NO}_{2}$ , can be reduced to phenylamine, $\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{NH}_{2}$ , in acid solution in a two step process.

(a)

Phenol can be synthesised from phenylamine in two steps.

[ 3 ]

(i)

State the reagents and conditions for steps 1 and 2.
step 1
step 2

[ 2 ]

(ii)

Draw the structure of the intermediate compound E in the box above.

[ 1 ]

[Maximum number: 12]

Ethylamine and phenylamine are primary amines.

Fig. 4.1

These two compounds are synthesised by different methods.

(a)

Ethylamine is a weak base.

State the relative basicities of ammonia, ethylamine and phenylamine.
Explain your answer. < <
least basic
most basic

[ 4 ]

(b)

Pure phenylamine, $\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{NH}_{2}$ , can be prepared from benzene in two steps.

Draw the structure of the intermediate compound.
Suggest reagents and conditions for each step.

[ 3 ]

(c)

Fig. 4.2 shows some reactions of phenylamine.

Fig. 4.2

[ 5 ]

(i)

Draw the structure of W, the organic product of reaction 1 .

[ 1 ]

(ii)

State the reagents used in reaction 2 .

Benzenediazonium chloride, $\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{~N}_{2} \mathrm{C}$ l, and X react together in reaction 4 to form Y, an azo compound.

[ 1 ]

(iii)

Name X, the organic product of reaction 3 .

[ 1 ]

(iv)

State the necessary conditions for reaction 4 to occur.

[ 1 ]

(v)

Suggest a use for Y.

[ 1 ]

(a)

A polymer, P, can be made from the monomers benzene-1,4-dioyl chloride and benzene-1,3-diamine.

benzene-1,4-dioyl chloride

benzene-1,3-diamine

[ 2 ]

(i)

Benzene-1,3-diamine can be made from benzene using the reaction sequence shown.

State the reagents used for steps 1 and 3.
step 1
step 3

[ 2 ]

(a)

Suggest how the basicity of benzocaine would compare to that of ethylamine. Explain your answer.

[ 2 ]

(b)

Benzocaine can also be used to synthesise the dyestuff S by the following route.

[ 1 ]

(i)

Suggest the reagents used for step 1.

[ 1 ]

[Maximum number: 3]

Phenol is an important industrial chemical used in the manufacture of dyestuff and other substances.

(a)

2-naphthol

2-naphthol can show similar properties to phenol. It can be used to produce Sudan I, an orange coloured dyestuff.

Sudan I

[ 3 ]

(i)

Describe how Sudan I can be made using phenylamine and 2-naphthol as the organic starting materials.

[ 3 ]