Organic Chemistry Multiple Choice Questions on “Reduction of Pyridine”.
1. What will be the product if reaction with hydrogen gas in the presence of Raney nickel takes place?
a) Pyrimidine
b) Piperdine
c) Pyrylium salt
d) Pentazine
Answer: a
Clarification: Hydrogen-saturated piperidine is obtained through reaction with hydrogen gas in the presence of Raney nickel.
2. What is name of the reaction when piperdine is converted by pyridine commercially?
a) Dehydrogenation
b) Hydrogenation
c) Hydrogenolysis
d) Transfer hydrogenation
Answer: b
Clarification: Piperidine is commercially obtained by the hydrogenation of pyridine using nickel catalyst at about 200℃.
3. By which of the following agent there will be incomplete reduction of pyridine?
a) Na-NH2, EtOH
b) H2/RaNi, 200℃
c) Na/C2H5OH
d) NaBH3
Answer: a
Clarification: NaNH2 in presence of ethanol will form 1, 4-dihydropyridine when undergoes partial hydrogenation of pyridine take place.
4. When Lithiumtetrahydroborate in the presence of water reacts with pyridine, which product is formed?
a) Piperidine
b) 1,4-dihydropyridine
c) 1,2-dihydropyridine
d) 2,5-dihydropyridine
Answer: b
Clarification: Selective synthesis of 1,4-dihydropyridine is achieved in the presence of organometallic complexes of magnesium and zinc, and Lithiumtetrahydroborate in the presence of Water.
5. When lithium aluminium hydride reacts with pyridine, which product is not formed?
a) Piperidine
b) 1,4-dihydropyridine
c) 1,2-dihydropyridine
d) 2,5-dihydropyridine
Answer: a
Clarification: Partially hydrogenated derivatives are obtained under milder conditions, reduction with lithium aluminium hydride yields a mixture of 1,4-dihydropyridine, 1,2-dihydropyridine, and 2,5-dihydropyridine.
6. What will be the product of the following reaction?
a) 
b) 
c) 
d) 
