(a) Explain why amides are much weaker bases than amines. [2] (b) Fig. 9.1 shows the preparation of 2-phenylethylamine, C6H5CH2CH2NH2, by three different routes. [Figure 9.1] (i) Suggest structures for compounds M and N and draw them in the boxes in Fig. 9.1. [2] (ii) Give the reagents and conditions for reaction 1. [1] (c) Fig. 9.2 shows compound H which is a useful starting material in organic synthesis. [Figure 9.2] Η contains an alkene and an amine functional group. Name the other functional group and give the classification of the amine group in H. other functional group in H classification of amine [1] (d) Ozonolysis involves the oxidative cleavage of a C=C bond in alkenes using ozone, O3, as shown in Fig. 9.3. [Figure 9.3] Fig. 9.4 shows the first step in this reaction which involves the formation of an ozonide intermediate. [Figure 9.4] (i) On Fig. 9.4, draw three curly arrows to complete the mechanism of this step. [2] (ii) L is formed from alkene K, C8H14, by a similar reaction to that shown in Fig. 9.3. [Figure L] Suggest the structure of K. [drawing box] [1]
- (a)Explain why amides are much weaker bases than amines.[2]
- (b)(i)Suggest structures for compounds M and N and draw them in the boxes in Fig. 9.1.[2]
- (b)(ii)Give the reagents and conditions for reaction 1.[1]
- (c)Η contains an alkene and an amine functional group. Name the other functional group and give the classification of the amine group in H. other functional group in H classification of amine[1]
- (d)(i)On Fig. 9.4, draw three curly arrows to complete the mechanism of this step.[2]
- (d)(ii)L is formed from alkene K, C8H14, by a similar reaction to that shown in Fig. 9.3. [Figure L] Suggest the structure of K. [drawing box][1]
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Mark scheme
Marking points from the official mark scheme (Oct/Nov 2025). The mark or mark type is shown in brackets.
- [2] (a) M1: (basicity linked to) ability of lone pair / p-orbital to AND accept / coordinate with a proton / H+ M2: (lone pair of) electrons on N is delocalised into C=O group (and make amides neutral)
- [2] (b)(i) M1: M [drawing of C6H5CH2CN] M2: N [drawing of C6H5CH2CH2Br]
- [1] (b)(ii) LiAlH4
- [1] (c) ketone / carbonyl AND secondary / 2°
- [2] (d)(i) curly arrow 1: from O lone pair to C atom (in C=C) curly arrow 2: from C=C bond to the right-hand O atom in O=O curly arrow 3: from O=O bond to O+
- [1] (d)(ii) [drawing of 1-methylcyclopent-1-ene]
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