Claisen and Cross Claisen condensation Flashcards
1
Q
- Which of the following is a product formed in Claisen
condensation?
a) β- ester
b) β-ketone
c) β-keto ester
d) Y-diketone
A
a) β- ester
2
Q
- Which type of precursor is used as reactant in
intramolecular Claisen condensation?
a) One molecule with an ester end
b) Two molecules of ester
c) One molecule with two ester ends
d) One molecule of ester and enolate
A
c) One molecule with two ester ends
3
Q
- Which of the following stamen is incorrect about Claisen
condensation?
a) The product is a β-keto ester which resists
deprotonation by the strong base in the reaction mixture
b) The reaction involves the condensation of two esters in
the presence of strong base
c) A strong base is required to remove H+ from an α-H
position in one of the starting esters
d) A strong base is required to remove H+ from an α-H
position in one of the starting esters
A
a) The product is a β-keto ester which resists
4
Q
- Lye is used in soap-making. Lye is a concentrated
solution of which ionic compound?
a) K2CO3
b) CuSO4
c) NaOH
d) NaCl
A
a) K2CO3
5
Q
- Which of the following term describe saponification?
a) Cleaving of ester molecules into carboxylic acid and
alcohol
b) Dehydration synthesis by removing water
c) Hydrolysis of a salt by adding a weak acid
d) Synthesis of two alkyl groups to make an ether
A
a) Cleaving of ester molecules into carboxylic acid and
alcohol
6
Q
- Which of the following is considered a useful alkali in
saponification reactions?
a) CCl4
b) Cl–
c) NaOH
d) Pb+
A
c) NaOH
7
Q
- Saponification value is the number of milligrams of KOH
required to saponify what present in the 1g of oil or fat?
a) Salts
b) Hydrocarbon
c) Fatty acids
d) unsaturation
A
c) Fatty acids
7
Q
- Which of the following is a product formed in Claisen
condensation?
a) β- ester
b) β-ketone
c) β-keto ester
d) Y-diketone
A
c) β-keto ester
7
Q
- Which of the following compound is an industrial
manufacturing product by saponification?
a) Sodium chloride
b) Potassium hydroxide
c) Glycerol
d) Sodium hydroxide
A
c) Glycerol
7
Q
- Which of the following fat or oil is unsaponifiable?
a) Paraffin wax
b) Bee wax
c) Olive oil
d) Shea butter
A
a) Paraffin wax
7
Q
- Which of the following statement is true about
saponification value of oil?
a) The shorter the chain of fatty acid, the higher is the
saponification value
b) The shorter the chain of fatty acid, the higher is the
saponification value
c) The higher the saturation in chain of fatty acid, the
lower is the saponification value
d) The lower the saturation in chain of fatty acid, the
higher is the saponification value
A
a) The shorter the chain of fatty acid, the higher is the
saponification value
8
Q
- Soap can be precipitated out by salting by using which
chemical compound?
a) Sodium chloride
b) Potassium hydroxide
c) Glycerol
d) Sodium hydroxide
A
a) Sodium chloride
9
Q
- Which of the following stamen is incorrect about Claisen
condensation?
a) The product is a β-keto ester which resists
deprotonation by the strong base in the reaction mixture
b) The reaction involves the condensation of two esters in
the presence of strong base
c) A strong base is required to remove H+ from an α-H
position in one of the starting esters
d) A strong base is required to remove H+ from an α-H
position in one of the starting esters
A
a) The product is a β-keto ester which resists
deprotonation by the strong base in the reaction mixture
10
Q
- Which type of precursor is used as reactant in
intramolecular Claisen condensation?
a) One molecule with an ester end
b) Two molecules of ester
c) One molecule with two ester ends
d) One molecule of ester and enolate
A
c) One molecule with two ester ends
10
Q
- Dieckmann Condensation is intramolecular
condensation of ……. to form cyclic product.
a) diamide
b) diol
c) diester
d) diketone
A
c) diester
11
Q
- What is the other name for the intramolecular Claisen
condensation?
a) Perkin condensation
b) Stobbe condensation
c) Knoevenagel condensation
d) Dieckmann condensation
A
d) Dieckmann condensation
12
Q
- Ethylamine can be prepared by the action of bromine
and caustic potash on which compound?
a) Acetamide
b) Propionamide
c) Formamide
d) Methyl cyanide
A
b) Propionamide
13
Q
- The amine formed from an amide by means of bromine
and alkali has how many number of carbon atoms?
a) Same number of C atoms as that of amide
b) One less C atom than that of amide
c) One more C atom than that of amide
d) Two more C atoms than that of amide
A
b) One less C atom than that of amide
13
Q
- When methyl iodide is heated with ammonia, what is
the product obtained?
a) Methylamine
b) Dimethylamine
c) Trimethylamine
d) A mixture of the above three amines
A
d) A mixture of the above three amines
13
Q
- Reduction of nitroalkanes yields which compound?
a) Acid
b) Alcohol
c) Amine
d) Diazo compounds
A
b) Alcohol
14
Q
- Which one of the following compound gives a secondary
amine on reduction?
a) Nitromethane
b) Nitrobenzene
c) Methyl isocyanide
d) Methyl cyanide
A
c) Methyl isocyanide
14
Q
- The Hinsberg’s method is used for which of the
following?
a) Preparation of primary amines
b) Preparation of secondary amines
c) Preparation of tertiary amines
d) Separation of amine mixtures
A
d) Separation of amine mixtures
14
Q
- What is the name of the reaction when acetamide
changes into methylamine?
a) Hofmann bromamide reaction
b) Hofmann reaction
c) Friedel-Craft’s reaction
A
a) Hofmann bromamide reaction
15
Q
- When ethanol is mixed with ammonia and passed over
alumina the compound formed is which compound?
a) C2H5NH2
b) C2H4
c) C2H5OC2H5
d) CH3OCH3
A
a) C2H5NH2
16
Q
- Which of the following reactions will not give primary
amine?
a) CH3CONH2 + KOH.Br2
b) CH3CN + LiAlH4
c) CH3NC + LiAlH4
d) CH3CONH2 + LiAlH4
A
c) CH3NC + LiAlH4
17
Q
- Which type of amine is produced by reaction of ketones
with primary amines, followed by reduction?
a) Secondary Aromatic amine
b) N-substituted amine
c) N, N-disubstituted amine
A
b) N-substituted amine
17
Q
- Which type of amine is produced by reaction of
ketones with secondary amines, followed by reduction?
a) Secondary Aromatic amine
b) N-substituted amine
c) N, N-disubstituted amine
d) Primary aromatic amine
A
c) N, N-disubstituted amine
18
Q
- What is the characteristic smell of liquid amines?
a) Fish like smell
b) Rotten egg smell
c) Fruity smell
d) Bitter almond smell
A
a) Fish like smell
18
Q
- Which of the following have less melting point than
amine?
a) Alcohol
b) Phosphine
c) Carboxylic acid
d) Ether
A
b) Phosphine
18
Q
- Which of the following compound is expected to be
most basic?
a) Aniline
b) Methylamine
c) Hydroxylamine
d) Ethylamine
A
d) Ethylamine
19
Q
- A solution of methyl amine shows which type of
property with litmus paper?
a) Turns blue litmus red
b) Turns red litmus blue
c) Does not affect red or blue litmus
d) Bleaches litmus
A
b) Turns red litmus blue
19
Q
- Which of the following statement is true about methyl
amine?
a) Methyl amine is slightly acidic
b) Methyl amine is less basic than NH3
c) Methyl amine is stronger base than NH3
d) Methyl amine forms salts with alkali
A
c) Methyl amine is stronger base than NH3
19
Q
- By the presence of a halogen atom in the ring, what is
the effect of this on basic properties of aniline?
a) Increased
b) Decreased
c) Unchanged
d) Doubled
A
a) Increased
20
Q
- If methyl is alkyl group, then which order of basicity is
correct?
a) R2NH > RNH2 > R3N > NH3
b) R2NH > R3N > RNH2 > NH3
c) RNH2 > NH3 > R2NH > R3N
d) NH3 > RNH2 > R2NH > R3N
A
a) R2NH > RNH2 > R3N > NH3
20
Q
- Which statement is an incorrect statement?
a) Amines form hydrogen bond
b) Ethyl amine has higher boiling point than propane
c) Methyl amine is more basic than ammonia
d) Dimethyl amine is less basic than methyl amine
A
d) Dimethyl amine is less basic than methyl amine
21
Q
- Which of the following amine has highest boiling point?
a) Butyl amine
b) Diethylamine
c) Triethylamine
d) Dipropylamine
A
d) Dipropylamine
21
Q
- Unpleasant smelling carbylamines are formed by
heating alkali and chloroform with which of the following?
a) Any amine
b) Any aliphatic amine
c) Any aromatic amine
d) Any primary amine
A
d) Any primary amine
21
Q
- What is the correct decreasing order of the basic
character of the three amines and ammonia?
a) NH3 > CH3NH2 > C2H5NH2 > C6H5NH2
b) C2H5NH2 > CH3NH2 > NH3 > C6H5NH2
c) C6H5NH2 > C2H5NH2 > CH3NH2 > NH3
d) CH3NH2 > C2H5NH2 > C6H5NH2 > NH3
A
b) C2H5NH2 > CH3NH2 > NH3 > C6H5NH2
22
Q
- Which of the following is most basic?
a) C6H5NH2
b) (CH3)2NH
c) (CH3)3N
d) NH3
A
b) (CH3)2NH
23
Q
- Among the following, which one is the strongest base?
a) C6H5NH2
b) p−NO2C6H4NH2
c) m−NO2−C6H4NH2
d) C6H5CH2NH2
A
d) C6H5CH2NH2
23
Q
- Which of the following is true characteristic feature of
aniline?
a) Colourless solid
b) Brown coloured solid
c) Colourless liquid
d) Brown coloured liquid
A
c) Colourless liquid
24
Q
- The correct order of basicity of amines in water is
which of the following?
a) (CH3)2NH > (CH3)3N > CH3NH2
b) CH3NH2 > (CH3)2NH > (CH3)3N
c) (CH3)3N > (CH3)2NH > CH3NH2
d) (CH3)3N > CH3NH2 > (CH3)2NH
A
a) (CH3)2NH > (CH3)3N > CH3NH2
25
Q
- Which of the following is converted into an alcohol on
treatment with HNO2?
a) Methyl amine
b) Aniline
c) Dimethyl amine
d) Triethyl amine
A
a) Methyl amine
26
Q
- The action of nitrous acid on ethyl amine gives which of
the following?
a) Ethane
b) Ammonia
c) Ethyl acohol
d) Nitroethane
A
c) Ethyl acohol
27
Q
- p-chloroaniline and anilinium hydrochloride can be
distinguished by which test?
a) Sandmeyer reaction
b) NaHCO3
c) AgNO3
d) Carbylamine test
A
b) NaHCO3
27
Q
- Nitroso amines (R2N−N=O) are soluble in water. On
heating them with concentrated H2SO4 they give
secondary amines. What is this reaction called as?
a) Perkin’s reaction
b) Fittig’s reaction
c) Sandmeyer’s reaction
d) Liebermann’s nitroso reaction
A
d) Liebermann’s nitroso reaction
27
Q
- Aniline reacts with acetaldehyde to form which of the
following?
a) Schiff’s base
b) Carbylamine
c) Immine
d) Diazonium salt
A
c) Immine
28
Q
- Primary amines can be distinguished from secondary
and tertiary amines by reacting with which of the
following?
a) Chloroform and alcoholic KOH
b) Methyl iodide
c) Chloroform alone
d) Zinc dust
A
a) Chloroform and alcoholic KOH
28
Q
- Ethyl amine undergoes oxidation in the presence of
KMnO4 to form which compound?
a) An acid
b) An alcohol
c) An aldehyde
d) A nitrogen oxide
A
c) An aldehyde
29
Q
- When primary amines are treated with HCl, the product
obtained is which of the following?
a) An alcohol
b) A cyanide
c) An amide
d) Ammonium salt
A
d) Ammonium salt
29
Q
- Reaction of primary amines with aldehyde yields which
of the following compound?
a) Amides
b) Aldimines
c) Nitriles
d) Nitro compounds
A
b) Aldimines
30
Q
- The compound which on reaction with aqueous nitrous
acid on HNO2 at low temperature produces an oily
nitrosoamine is which of the following?
a) Diethylamine
b) Ethylamine
c) Aniline
d) Methylamine
A
a) Diethylamine
31
Q
- When an organic compound was treated with sodium
nitrite and hydrochloric acid in the ice cold, nitrogen gas
was evolved copiously. What is the compound?
a) A nitrocompound
b) A primary amine
c) An aliphatic primary amine
d) An aromatic primary amine
A
c) An aliphatic primary amine
31
Q
- When chloroform reacts with ethyl amine in presence
of alcoholic KOH, the compound formed is which of the
following?
a) Ethyl cyanide
b) Ethyl isocyanide
c) Formic acid
d) An amide
A
b) Ethyl isocyanide
32
Q
- The reaction of HNO2 with ‘A’ gives quaternary
ammonium salt. A is which of the following?
a) Methyl amine
b) Dimethyl amine
c) Trimethyl amine
d) Aniline
A
c) Trimethyl amine
32
Q
- Aniline on treatment with excess of bromine water
which of the following?
a) Aniline bromide
b) o-bromoaniline
c) p-bromoaniline
d) 2, 4, 6-tribromoaniline
A
d) 2, 4, 6-tribromoaniline
33
Q
- A primary amine can be converted to an alcohol by the
action of which of the following?
a) Alkali
b) Nitrous acid
c) Reducing agent
d) Oxidizing agent
A
b) Nitrous acid
34
Q
- The amine which can react with C6H5−SO2−Cl to form a
product insoluble in alkali shall be, is which of the
following?
a) Primary amine
b) Secondary amine
c) Tertiary amine
d) Both primary and secondary amines
A
b) Secondary amine
34
Q
- Primary amines react with nitrous acid to yield which
of the following?
a) Insoluble nitrite salts
b) Yellow oily layer
c) Nitrogen gas
d) Azo dye
A
35
Q
- A mixture of benzene and aniline can be separated by
which of the following?
a) Hot water
b) dil. HCl
c) dil. NaOH
d) Alcohol
A
b) dil. HCl
36
Q
- Nitration of aniline also gives m-nitro aniline, in strong
acidic medium because of which of the following reasons?
a) In electrophilic substitution reaction amino group is
meta directive
b) Inspite of substituents nitro group always goes to m-
position
c) In strong acidic medium, nitration of aniline is a
nucleophic substitution reaction
d) In strong acidic medium aniline present as anilinium ion
A
b) Inspite of substituents nitro group always goes to m-
position
37
Q
- An organic amino compound reacts with aqueous
nitrous acid at low temperature to produce an oily nitroso
amine. What is this compound?
a) CH3NH2
b) CH3CH2NH2
c) CH3CH2NH.CH2CH3
d) (CH3CH2)3
A
b) CH3CH2NH2
37
Q
- Reaction of aniline with benzaldehyde is which type of
reaction?
a) Polymerisation
b) Condensation
c) Addition
d) Substitution
A
b) Condensation
38
Q
- Electrophilic substitution of aniline with bromine in
presence of gacial acetic acid gives which of the following?
a) 1, 4, 6-tribromo aniline
b) 2, 4, 6-tribromo aniline
c) 4-bromo aniline
d) 3-bromo aniline
A
c) 4-bromo aniline
38
Q
- In the reaction, what is the compound C6H5N=CHC6H5is
known as?
C6H5CHO + C6H5NH2 → C6H5N=HCC6H5 + H2O
a) Aldol
b) Schiffs reagent
c) Schiffs base
d) Benedict reagent
A
c) Schiffs base
39
Q
- Ethyl amine on acetylation gives which of the following?
a) N-ethyl acetamide
b) Acetamide
c) Methyl acetamide
d) Propyl acetamide
A
a) N-ethyl acetamide
39
Q
- During acetylation of amines what is replaced by acetyl
groups?
a) Hydrogen atom attached to nitrogen atom
b) One or more hydrogen atoms attached to carbon atom
c) One or more hydrogen atoms attached to nitrogen atom
d) Hydrogen atoms attached to either carbon atom or
nitrogen atom
A
c) One or more hydrogen atoms attached to nitrogen atom
40
Q
- Aniline reacts with which of these to form Schiff base?
a) Acetic acid
b) Benzaldehyde
c) Acetone
d) NH3
A
b) Benzaldehyde
40
Q
- p-chloro aniline and anilinium hydrogen chloride can
be distinguished by which of the following?
a) Sandmaeyer reaction
b) Carbyl amine reaction
c) Hinsberg’s reaction
d) AgNO3
A
d) AgNO3
41
Q
- Aniline is usually purified by which of the following
method?
a) Steam distillation
b) Simple distillation
c) Vacuum distillation
d) Extraction with a solvent
A
a) Steam distillation
42
Q
- Reaction of cyclohexanone with dimethylamine in the
presence of catalytic amount of an acid forms a compound
if water during the reaction is continuously removed.
What is the compound formed is generally known as?
a) A Schiff’s base
b) An enamine
c) An imine
d) An amine
A
b) An enamine
42
Q
- The reductive amination of an aldehyde (e.g. the
reaction of propanal with ethylamine) can be carried out in
the laboratory using which of the following as a reducing
agent?
a) NaBH3CN
b) LiAlH4
c) BH3
d) NaBH4
A
a) NaBH3CN
43
Q
- Which type medium is required for the formation of
aniline by reaction of aryl boric acid and HAS?
a) Acidic
b) Basic aqueous
c) Neutral dry
d) aqueous
A
b) Basic aqueous
44
Q
- In the direct amination of alkyl and aryl pinacol
boronates to form aromatic amine, which of the following
is used as reagent with pinacol?
a) Aryl boric acid
b) Copper oxide
c) Pd(OAc)2
d) Lithiated methoxyamine
A
d) Lithiated methoxyamine
45
Q
- Which reducing agent is used for the reduction of nitro
compound to phenyl amine?
a) LiAlH4
b) Sn/HCl
c) Na/alcohol
d) H2/Ni
A
b) Sn/HCl
45
Q
- Which of the following method cannot be used for
preparation of aromatic amine?
a) Gabriel phthalimide synthesis
b) Reduction of nitro compound
c) Reduction of nitrile with LiAl4
d) Decarboxylation of amino acids
A
a) Gabriel phthalimide synthesis
46
Q
- What is the known name of the given reaction?
C6H5N+
2 + CuCl → C6H5Cl + N2 + Cu+
a) Gattermanns reaction
b) Sandmeyers reaction
c) Dehydrogenation reaction
d) Esterification reaction
A
b) Sandmeyers reaction
46
Q
- What is the general formula of Diazonium salt?
a) RN2^+X^–
b) RN^+
c) RXI
d) RN_2^+HSO^-2
A
a) RN2^+X^–
47
Q
- What is the known name of the given reaction?
C6H5N+
2 + CuX → C6H5X + N2 + Cu+
a) Gattermanns reaction
b) Sandmeyers reaction
c) Dehydrogenation reaction
d) Esterification reaction
A
a) Gattermanns reaction
48
Q
- What is the known name of the given reaction?
[C6H5N+
2]Cl− + C6H6 → C6H5−C6H5 + N2 + HCl
a) Gattermanns reaction
b) Sandmeyers reaction
c) Gomberg–Bachmann reaction
d) Esterification reaction
A
c) Gomberg–Bachmann reaction
48
Q
- What is the known name of the given reaction?
[C6H5N+
2]BF−
4 → C6H5F + BF3 + N2
a) Gattermanns reaction
b) Sandmeyers reaction
c) Dehydrogenation reaction
d) Balz-Schiemann reaction
A
d) Balz-Schiemann reaction
49
Q
- Benzene diazonium chloride when reacts with
hypophosphorus acid produces which of the following
compound?
a) Benzene
b) Phenyl phosphate
c) Phenol
d) Phenyl isocyanide
A
a) Benzene
49
Q
- What is the known name of the given reaction?
[C6H5N+2]Cl− + ArCH=CHCO2H → ArC=C−C6H5 + N2 + CO2 +
HCl
a) Gattermanns reaction
b) Sandmeyers reaction
c) Meerwein reaction
d) Balz-Schiemann reaction
A
a) Gattermanns reaction
50
Q
- When hypophosphorous acid is treated with diazonium
salts, it is reduced to which of the following compound?
a) Arene
b) Methane
c) Ethyl alcohol
d) Amines
A
a) Arene
50
Q
- p-amino azo benzene is obtained by treating diazonium
chloride with which of the following compound?
a) Benzene
b) Aniline
c) Phenol
d) Benzoic acid
A
b) Aniline
51
Q
- Which of the following amine will form stable
diazonium salt at 273-283 K?
a) C6H5NH2
b) C6H5N(CH3)2
c) C2H5NH2
d) C6H5CH2NH2
A
a) C6H5NH2
52
Q
- When diazonium salt solution is treated with KI, it
forms which of the following compound?
a) Bromobenzene
b) Iodobenzene
c) Phenol
d) Acid
A
b) Iodobenzene
52
Q
- Azo dye is prepared by the coupling of phenol and which
of the following compound?
a) Diazonium chloride
b) o-nitro aniline
c) Benzoic acid
d) Chlorobenzene
A
a) Diazonium chloride
52
Q
- Benzene diazonium chloride forms orange red dye with
which of the following compound?
a) Nitrophenol
b) Benzophenol
c) Resorcinol
d) Methanol
A
c) Resorcinol
52
Q
- Replacement of diazo group by other groups is helpful in
preparing those substituted aromatic compounds which
cannot be prepared which type of reaction?
a) Direct elimination
b) Addition reaction
c) Direct substitution
d) Replacement reaction
A
c) Direct substitution
53
Q
- What happens when benzene diazonium chloride is
treated with potassium cyanide in presence of Cu powder?
a) Benzophenone
b) Methyl isocyanide
c) Acetonitrile
d) Benzonitrile
A
d) Benzonitrile
53
Q
- By treating diazonium salts with cuprous cyanide or KCN
and copper powder it forms which of the following
compound?
a) Citric acid
b) Benzoic acid
c) Aryl nitrile
d) Oxalic acid
A
c) Aryl nitrile
54
Q
- Identify the product in following order when 3,4,5
Tribromoaniline undergoes diazotisation followed by
attack of H3PO2?
a) 3, 4,5-Tribromobenzene
b) 1, 2, 3-Tribromobenzene
c) 2, 4, 6-Tribromobenzene
d) 3, 4, 5-Tribromo nitro benzene
A
a) 3, 4,5-Tribromobenzene
55
Q
- When diazonium salt solution is treated with KI, it
forms which of the following compound?
a) Bromobenzene
b) Iodobenzene
c) Phenol
d) Acid
A
b) Iodobenzene
