1. Chapter 21 More About Amines Heterocyclic Compounds Organic Chemistry, 6 th edition Paula Yurkanis Bruice Brian L. Groh Minnesota State University, Mankato Mankato, MN Bruice: Organic Chemistry, © 2011 Pearson Education, Inc.

2. Which of the following heterocyclic amines is aziridine?21.1 A. Bruice: Organic Chemistry, © 2011 Pearson Education, Inc. B.C. D.E.

3. Which of the following heterocyclic amines is aziridine?21.1 A. Bruice: Organic Chemistry, © 2011 Pearson Education, Inc. B.C. D.E. azetidineaziridinepyrrolidine piperazinepiperidine

4. Which is the correct name for the following compound? 21.1 A.N-ethyl-1-methylpiperidine B.N-ethyl-3-methylpiperidine C.N-ethyl-1-methylpyrrolidine D.N-ethyl-3-methylpyrrolidine E.N-ethyl-3-methylazetidine Bruice: Organic Chemistry, © 2011 Pearson Education, Inc.

5. Which is the correct name for the following compound? 21.1 A.N-ethyl-1-methylpiperidine B.N-ethyl-3-methylpiperidine C.N-ethyl-1-methylpyrrolidine D.N-ethyl-3-methylpyrrolidine E.N-ethyl-3-methylazetidine The 6-membered heterocycle is a piperidine ring with the nitrogen atom assigned as the 1-position. Bruice: Organic Chemistry, © 2011 Pearson Education, Inc.

6. Which of the following amines would you predict to have the lowest pK a ? 21.8 A. Bruice: Organic Chemistry, © 2011 Pearson Education, Inc. B.C. D.E.

7. Which of the following amines would you predict to have the lowest pK a ? 21.8 A. Bruice: Organic Chemistry, © 2011 Pearson Education, Inc. B.C. D.E. pK a = 4.5 pK a = 40 pK a = 10.8 pK a = -2.4 pK a = 5.6 Resonance stabilization and loss of aromaticity greatly reduce nitrogen’s basicity.

8. Which compound is the product of the bromination shown below? 21.8 Bruice: Organic Chemistry, © 2011 Pearson Education, Inc.

9. Which compound is the product of the bromination shown below? 21.8 Pyrrole, furan, and thiophene undergo electrophilic substitution preferentially at C-2 because the intermediates are highly resonance stabilized. Bruice: Organic Chemistry, © 2011 Pearson Education, Inc.

10. A.1. Br 2 /FeBr 3 ; 2. PhLi B.1. HBr; 2. Ph 2 CuLi C.1. Br 2, heat; 2. PhLi D.1. Br 2 /FeBr 3 ; 1. Ph 2 CuLi E.Ph-Br/FeBr 3 Which set of reagents will accomplish the following transformation in good yield? 21.9 Bruice: Organic Chemistry, © 2011 Pearson Education, Inc.

11. A.1. Br 2 /FeBr 3 ; 2. PhLi B.1. HBr; 2. Ph 2 CuLi C.1. Br 2, heat; 2. PhLi D.1. Br 2 /FeBr 3 ; 1. Ph 2 CuLi E.Ph-Br/FeBr 3 Which set of reagents will accomplish the following transformation in good yield? 21.9 Electrophilic substitution on pyridine is facilitated at the 3-position but nucleophilic substitution is not so a Gillman reagent is needed. Bruice: Organic Chemistry, © 2011 Pearson Education, Inc.

12. Which of the following heterocyclic amines is pyrimidine? 21.10 A. Bruice: Organic Chemistry, © 2011 Pearson Education, Inc. B.C. D.E.

13. Which of the following heterocyclic amines is pyrimidine? 21.10 A. Bruice: Organic Chemistry, © 2011 Pearson Education, Inc. B.C. D.E. imidazolepyrrolepyridine purinepyrimidine