Answer Key for Mid-term exam 3 Form A

CHEM 2420 --Organic Chemistry II Fall 2015 Mid-Exam No. 3: Chapter 19-20 (Form A) Name: ,) ÿ_aÿ Instructions: A) Please print your name on the line above. B) Please write and bubble your name and bulÿble your answers on the scantron sheet. C) Make sure you have 10 pages. D) Good luck! Question Score Multiple choice /80 Bonus Total Free response /20 /5 /105 1 IPaÿoe Section 1. Multiple Choice (80 points) Bubble the choice that best completes each phrase and/or answers the question on the Scantron sheet provided. Answers written in this section of the exam will NOT be graded (20 X 4 = 80 points), 1. What is the IUPAC name of the following compound? COON CH3 @ 5-chloro-4-methylbenzoic acid 3-chloro-4-methylbenzoic acid c. 4-methyl-5-chlorobenzoic acid d. 3-chloro-4-methylbenzaldehyde 2. What is the correct assignment of the names of the following heterocycles? 4 a. 1 = pyrrole; 2 = thiophene; 3 = pyridine; 4 = piperidine b. 1 = thiophene; 2 = furan; 3 = pyrrole; 4 = imidazole c. 1 = pyridine; 2 = thiophene; 3 = pyrrole; 4 = furan 1 = pyridine; 2 = pyrrole; 3 = thiophene; 4 = imidazole . a, s b. sp What is the hybridization of the oxygen atom of tetrahydrofuran(THF)? 2 IP a g e 4. Which of the following heterocycles 1 2 4 a. 4 b. 2and4 c. 3 and 4 ')d'. 1 and 3 ° J Which of the following has the substituted phenols shown in the correct order o{ decreasing acidit phenolic hydrogen atom (i.e., more acidic less acidic)? ................. NO2 CH3 OMe Cl 1 2 3 4 a. 4321 b. 4231 c. 423 .'4123 , What is the major organic product obtained from the following reaction? COOH COOH excess H2CrO4 COOH COOH HOOC COOH a. 1 b. 2 G;)3 d. 4 3 IP a ÿ' e 7. What is the major organic product obtained from the following reaction? COOCH3 COOCH3 COOCH3 COOCH3 CH3CI, AICI3 CH3 3 a. 1 b. 2 , Which of the following substituents is ortho/para directing and deactivating in electrophilic aromatic substitution reactions? a. COCH3 b. NHCOCH3 .r CHzCH3 9. What is the electrophile in the reaction of benzene with ethanoyl chloride and A1C13? C. (CH3)3C+ d. benzene 10. What is the electrophile in the reaction of aniline with sodium nitrite and hydrochloric acid to form arene diazonium salt? a. NO2+ NO+ c. N2+ d. NH2+ 11. Which of the following sets of substituents are all ortho/para directing in electrophilic aromatic substitution reactions? "ÿ a. C1, CH3, CN, NH2 b. Br, OH, COCH3, NHCH3 OH, CH3, NHCOCH3 4{Page d, OCH3, CN, NO2, COCH3 12. Which of the following sets of substituents are all meta directing in electrophilic aromatic substitution reactions? a. CH3, OH, Br, CF3 '@bd. CCO1,C NHH32, ,N CON2, ,S COO3OHH, CN . NH2, COCH3, OH, NH3+ 13. Which of the following sets of substituents are all activating groups in electrophilic aromatic substitution reactions? a. CH3, OCH3, COCH3, NH2 b. C1, CN, NH2, NO2 c. el, NH2, CH3, COCH3 (ÿ CH3, NH2, phenyl, OCH3 14. What is the major organic product obtained from the following y.y. ÿ- COOCH3 COOCH3 COOCHa COOCH3 COOCHa HNOa, H2SO4 '1," ÿ("ÿ J :N NO2 2 a. 1 2 4 15. Which of the following is the structure for N-methylpyrrolidine (N-methylazacyclopentane)? 51Page I, IH IV, IH Vl 1", A)I E) V 16. Which of the following compounds are secondary (2°) amines? 1. (CH3CH2)3CNHC6H5 %ÿ} 2. CH3CH2CH(NH2)CH2CH2CH2CH3 3. CHBCH2CH2NHCH2CH3 Z ÿ 4. CHBCH2CH2CH2CH2N(CH2CH3)2 a. 1 and 2 ,. 1, ,a2n adn 3d 3 d. 1, 2, 3 and 4 17. What is the hybridization of the nitrogen atoms labeled i, ii, and iii in the following molecule? iii i H ii a. i = sp2;; ii = sp2; iii = sp3 b. i = sp2; ii = sp3; iiÿ sp2 i = sp2; ii = sp2; iii= $1)2 i sp3; ii = sip2; ii['= sp2 61Paÿ,,e 18. What is the major organic product obtained from the 1. NaNO2, HCI 2. KI Br Br E}r I 3 4 Br a, 1 @2 C. 3 d. 4 19. Give the major product for the following reaction. Br2 ar Br S 2 c. 3 d. 4 20. Give the major product for the following reaction. 7lPage NO2 1 NO2 1. HNO3, H2SO4 2. NaOH ) C. 3 d. 4 81PaSe Section 2. Free Response (20 points) Write CLEARLY in complete sentences o1" show all work if the problem calls for it. Remember to show all lone pair electrons if drawing a mechanism. o Mechanism. Draw the mechanism by which the following reaction occurs. Be sure to show curved arrows to indicate the movement of electrons as well as all lone pair electrons. (2 X 6 = 12 points) a. ,!'ÿ'N ÿ @ Q AICI3 @ lO € Aÿcl} b, NO2 OCH3 NO2 OCH3 4/ ,,f %+../1o r p " M.7 9lPaoe 42, . Synthesis, Provide all reactants, reagents, and intermediate products for preparation of the following product from starting material (8 points). SO3H CH3 CH3 %Y I q-._ Bonus (5 points): Draw the other FOUR resonance structures of pyrrole. ,ÿ:.O N ' O H © 4 -0 4 ,l 10]Page