Pharmaceutical Chemistry Questions and Answers

1. Which of the following is an example of a carrier linked tripartite prodrug?
(a) Becampicillin
(b) Carbenicillin sodium
(c) Chloramphenicol palmitate
(d) Sulfisoxazole diacetate

2. In which of the following named reactions Tosylhydrazone is used as protecting group for alcohols and amines to obtain chemo selectivity in a multistep reaction?
(a) Sandmeyer reaction
(b) Dieckmann reaction
(c) Doebner Miller reaction
(d) Shapiro reaction

3. Which of the following antiviral agents does not act by inhibiting Reverse transcriptase?
(a) Abacavir
(b) Zidovudine
(c) Cytarabine
(d) Didanosine

4. Which of the following antiepileptic, a sulphonamide derivative inhibits T type Ca++ currents and like phenytoin delays the recovery of inactivated Na+ channels?
(a) Ethosuximide
(b) Zonisamide
(c) Gabapentin
(d) Lamotrigine

5. Which of the following is not a type of Stereoisomers
(a) Enantiomers
(b) Gauche
(c) Diastereomer
(d) Meso compounds

6. Which of the following name reactions does not yield homologues of quinoline?
(a) Doebner-miller synthesis
(b) Pfitzinger reaction
(c) Conrad-Limpach synthesis
(d) Chichibabin reaction

7. The number of signals in 13C NMR spectra for 1-butanol, 2-butanol, t-butyl alcohol and isobutyl alcohol are______
(a) 4, 3, 2, 4
(b) 4, 4, 3, 2
(c) 4, 4, 2, 3
(d) 4, 3, 2, 3

8. The high resolution pmr spectrum of n-butanol exhibits ___ split peak for the aldehyde proton?
(a) No
(b) Doublet
(c) Triplet
(d) Quartet

9. Typical value of coupling constant (Jab) for Geminal system is ethylene is ___
(a) 12 Hz
(b) 2 Hz
(c) 7 Hz
(d) 15 Hz

10. Application of Woodward-Fieser Rule on -Terpinene showed absorption maxima at-
(a) 232 nm
(b) 247 nm
(c) 273 nm
(d) 224 nm

11. Acetone shows absorption peak in the UV spectrum at 274 nm attributed to which among the following transition band?
(a) R- band
(b) B – band
(c) E- band
(d) K- Band

12. S-H str vibration peak of thiols is observed in the infra-red spectrum approximately around-
(a) 3400 cm-1
(b) 3100 cm-1
(c) 2900 cm-1
(d) 2600 cm-1

13. The homolytic bond dissociation energy is inversely proportion to the _____________
(a) Bond length
(b) Ease of formation
(c) Dipole moment
(d) Unit charge

14. Fuming sulphuric acid is the solution of ________________% SO3 in conc H2SO4.
(a) 10
(b) 9
(c) 8
(d) 7

15. Which of the following is correct for alkyl halide?
(a) Alkyl halide will always show S41 mechanism
(b) In unimolecular reaction, increasing the temperature do not favour E1 mechanism
(c) As branching at carbon increases, E1 mechanism is favoured as compared to SN1 mechanism
(d) In most unimolecular reactions of alkyl halide E1 reaction is favoured over S N1

16. With which of the following can ethanoic anhydride not undergo a substitution reaction?
(a) NaCl in CH3CO2H
(b) Aqueous NaOH
(c) CH3OH
(d) CH 3NH2

17. C = C str vibration in methylene cyclohexane is found at 1651 cm-1, while for methylene cyclobutane, the C = C str vibration peak is found at-
(a) 1657 cm-1
(b) 1690 cm-1
(c) 1651 cm-1
(d) 1645 cm-1

18. On hydrolysis Gitoxin yields Gitoxigenin and
(a) 1 molecule of Digitoxose
(b) 3 molecules of Digitoxose
(c) 1 molecule of Digitalose
(d) 3 molecules of Digitalose

19. Nine carbon rich side chain of Retinol contains __ number of unsaturated alkene units-
(a) 1
(b) 2
(c) 3
(d) 4

20. The hetero unit of Vitamin B9 linked to p-aminobenozic acid is __
(a) Pteridyl
(b) Pyridyl
(c) Pyrazinyl
(d) Pyridazinyl

21. Which of the following has largest equilibrium constant for the formation of a cyanohydrin?
(a) Acetaldehyde
(b) Acetone
(c) Propanal dehyde
(d) Benzaldehyde

22. Which of the following statements regarding mechanisms of elimination reaction is incorrect?
(a) The E2 mechanism generally occur under highly basic conditions.
(b) The E1 mechanism does not require a base
(c) The E2 mechanism is stereospecific.
(d) The E1cB mechanism is usually unim olecular in the rate determining step but leads to a second order rate law.

23. o, m and p-xylenes can be differentiated on basis of proton decoupled 13C NMR spectra; since o, m and p-isomers of xylene exhibits ____ signals respectively-
(a) 4, 5, 3
(b) 3, 4, 5
(c) 5, 4, 3
(d) 4, 3, 5

24. The proton on penultimate carbon in the carbon chain of 2-methyl-1-propanol shows a ___peak in high resolution pmr spectrum?
(a) Septet
(b) Quartet
(c) Quintet
(d) Nonet

25. The cis-protons of cis-3-chloropropenoic acid exhibits coupling constant for the doublet peak at__
(a) 2 Hz
(b) 5 Hz
(c) 9 Hz
(d) 14 H z

26. β-Phellandrene shows strong absorption in UV region and the maxima calculated on application of Woodward -Fieser rule is at __nm?
(a) 229 nm
(b) 247 nm
(c) 263 nm
(d) 273 nm

27. In which type of projection are staggered and eclipsed conformations used?
(a) Wedge Projection
(b) Newman Projections
(c) Sawhorse Projection
(d) Fischer Projection

28. Which of the following is known as Baker-Nathan effect?
(a) Hyperconjugation
(b) Mesomeric effect
(c) Inductive effect
(d) Electromeric effect

29. The shape of carbocation is_______________
(a) Pyramid
(b) Double Dumble
(c) Trigonal Planar
(d) Linear

30. What is the correct order of nucleophilicity in the following process?
(a) (CH3)2CO->CH3-
(b) CH3CH2CH2O-<((CH3)2CO-
(c) CH3S->CH3SH
(d) (CH3CH2)3N>(CH3CH2)3P

31. Among the following compounds, what is the decreasing order of reactivity towards electrophilic substitution?
I -Toluene
II – Benzene
III – Anisole
IV – Benzotrifluoride
(a) III > I > II > IV
(b) IV > I > II > III
(c) II > III > II > IV
(d) I > III > II > IV

32. The formal charge at Carbanion is ________
(a) +1
(b) -1
(c) 0
(d) + 2

33. Cut-off minimum wavelength for use of chloroform as solvent in UV spectroscopy is ___
(a) 190 nm
(b) 200 nm
(c) 220 nm
(d) 240 nm

34. An auxochrome that causes hypsochromic shift is ___
(a) Amino group
(b) Hydroxyl group
(c) Chloro group
(d) Methyl group

35. A characteristic ketene peak is generally observed in the infra-red spectrum at-
(a) 1720 cm-1
(b) 1675 cm-1
(c) 2150 cm-1
(d) 1890 cm-1

36. 17α -Ethynyl-18-methyl-19-nortestosterone is –
(a) Ethynylestrol
(b) Mestranol
(c) Levonorge strel
(d) Ethisterone

37. β-carotene on symmetrical cleavage in presence of the enzyme , β, β -carotene-15-15′-dioxygenase and -tocopherol forms ?
(a) Retinal
(b) Retinol
(c) Retinoic acid
(d) β-Apocarote nal

38. Vitamin E comprises of a basic nucleus of ______ to which a number of substituents and side chain is attached?
(a) Benzodihydropyran
(b) Benzodihydrofuran
(c) Benzopyran
(d) Benzofuran

39. The corrin nucleus comprises of ___ number of Carbon atoms.
(a) 18
(b) 19
(c) 20
(d) 21

40. C = O str of β-lactam ring is generally observed as peak in the infra-red spectrum of ampicillin around-
(a) 1825 cm-1
(b) 1780 cm-1
(c) 1745 cm-1
(d) 1700 cm-1

41. Proscillaridin is a _____
(a) Cardenolide
(b) Bufadienolide
(c) Isocardienolide
(d) Isobufadienolide

42. The hetero unit of Vitamin B9 linked to p-aminobenozic acid is-
(a) Pteridyl
(b) Pyridyl
(c) Pyrazinyl
(d) Pyridazinyl

43. Which among the following amino acid is essential for the biosynthesis of a Vitamin B3 compound in liver?
(a) Leucine
(b) Threonine
(c) Tryptophan
(d) Lysine

44. McLafferty’s rearrangement in 3-methylbutanal yields a strong base peak in the mass spectrum at m/z of :
(a) 86
(b) 58
(c) 44
(d) 42

45. The carbonyl carbon of crotonaldehyde gives a peak in 13C NMR spectrum at __ ppm.
(a) 114.3
(b) 139.2
(c) 152.9
(d) 192.2

46. Which of the following drug block voltage dependent sodium channels at high firing frequencies to bring about antiepileptic action?
(a) Vigabatrin
(b) Lorazepam
(c) Felbamate
(d) Zonisamide

47. Which of the following anticonvulsants, a tricyclic compound acts by modulation of voltage gated channels?
(a) Carbamazepine
(b) Phenytoin
(c) Zonisamide
(d) Vigabatrin

48. This tricyclic drug, overall is a NE and 5-HT reuptake blocker with significant anticholinergic and sedative properties and an oxa congener of amitriptyline.
(a) Dothiepin
(b) Doxepin
(c) Nortriptyline
(d) Trimipramine

49. In which of the following named reactions DEAD (Di Ethyl Azo Dicarboxylate) is used as a reagent?
(a) Mitsunobu reaction
(b) Michael addition
(c) Doebner Miller reaction
(d) Shapiro and Suzuki reaction

50. Which of the following is not a type of covalently binding enzyme inhibitors?
(a) Rapid reversible inhibitors
(b) Affinity label
(c) Mechanism based inhibitors
(d) Pseudo irreversible inhibitors