Edexcel Jan 2017 (IAL) Paper 5 Q21

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SECTION B Answer ALL the questions. Write your answers in the spaces provided. 21 Compounds derived from benzene have many uses, including as dyes and drugs. (a) Sudan I is an intense orange-red azo dye that is used to colour waxes, oils and polishes. It can be prepared from benzene using the reaction scheme shown. D O N O T W R I T E I N T H I S A R E A Step 1 conc. HNO3 conc. H2SO4 55C NO2 Step 2 NH2 nitrobenzene phenylamine HO Sudan I Step 3 NaNO2 HCl(aq) 010C Step 4 benzenediazonium chloride (i) Give the mechanism of the reaction taking place in Step 1, including an equation for the formation of the electrophile. (4) 10 *P48373A01032* D O N O T W R I T E I N T H I S A R E A D O N O T W R I T E I N T H I S A R E A<br /> (ii) Identify the reagents needed in Step 2. (1)(iii) Explain why, in Step 3, the temperature should not be higher than 10C. (1)A E R A S I H T N I E T I R W T O N O D (iv) Draw the structure of benzenediazonium chloride, showing all the bonds in the side-chain and any charges. A E R A S I H T N I E T I R W T O N O D (v) Draw the structure of the organic compound needed to produce Sudan I from benzenediazonium chloride in Step 4. (1) (1) A E R A S I H T N I E T I R W T O N O D *P48373A01132* 11 Turn over<br /> (b) Sudan IV is another azo dye. The first step of a suggested synthesis of Sudan IV involved the preparation of methylbenzene from benzene. Give the reagent and conditions to prepare methylbenzene from benzene. (2)D O N O T W R I T E I N T H I S A R E AD O N O T W R I T E I N T H I S A R E A D O N O T W R I T E I N T H I S A R E A 12 *P48373A01232*<br /> A E R A S I H T N I E T I R W T O N O D *(c) Benzyl benzoate is present in many asthma drugs. benzyl benzoate Outline how a chemist could synthesise a sample of benzyl benzoate in three or four steps, using benzaldehyde, C6H5CHO, as the only organic compound. Include the reagents and conditions for the steps in the synthesis and draw the structures of the intermediates. (5) A E R A S I H T N I E T I R W T O N O D A E R A S I H T N I E T I R W T O N O D (Total for Question 21 = 15 marks) *P48373A01332* 13 Turn over<br />

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