Active Methylene Compounds MCQs [Organic Chemistry]

MCQs-based questions and answers on Active Methylene Compounds in organic chemistry.

Malonic ester can be used to prepare which of the following?

  1. Carboxylic acids
  2. Amino acids
  3. Keto acids
  4. All A, B, and C

Question’s Answer: All A, B, and C

What is the order of percentage enolic character of malonic ester (I), acetoacetic ester (II) and cyanoacetic ester (III)?

  1. II>I>II
  2. III>II>1
  3. I>II>III
  4. II>III>I

Question’s Answer: II>III>I

For preparation of various monocarboxylic acids malonic ester hydrolysis is treated with which of the following?

  1. NaO C2H5
  2. Na/C2H5OH
  3. NaO C2H5
  4. RX

Question’s Answer: NaO C2H5

____is formed when Malonic ester reacts with urea in presence of POCI?

  1. Parabamic acid
  2. Barbituric acid
  3. Veronal
  4. Luminal

Question’s Answer: Barbituric acid

In its synthetic applications cyanoacetic ester closely resembles

  1. Ethyl acetoacetate
  2. Acetoacetic ester
  3. Nitroacetic ester
  4. Malonic ester

Question’s Answer: Malonic ester

The compound with which cyanoacetic ester can react but malonic ester cannot is

  1. Acetone
  2. Acetaldehyde
  3. Acid halide
  4. Alkyl halide

Question’s Answer: Acetone

The reaction used for the preparation of ethyl acetoacetate starting from ethyl acetate is known as

  1. Cannizzaro reaction
  2. Claisen condensation
  3. Michael condensation
  4. Clasien-Schmidt reaction

Question’s Answer: Claisen condensation

The enolic form of acetonacetic ester as compared to ketonic form contains ____.

  1. One extra lone pair
  2. One extra double bond
  3. One less double bond
  4. Both have same number of σ, л bonds and lone pairs

Question’s Answer: Both have same number of σ, л bonds and lone pairs

Why Keto-enol tautomerism arises?

  1. Due to Migration of enolic group
  2. Due to Migration of a keto group
  3. Due to Migration of a proton
  4. Due to Migration of hydroxyl group

Question’s Answer: Due to Migration of a proton

Which is true regarding Tautomers?

  1. Tautomers must have Dynamic equilibrium between functional isomers
  2. Tautomers must have Same functional group
  3. Tautomers must have Same position of double bond
  4. Tautomers must have Static equilibrium between functional

Question’s Answer: Tautomers must have Dynamic equilibrium between functional isomers

What is the order of enolic contents of CH3COCH2COOC2H5(I), CH3COCH2COCH3(II) and CH3COCH3CHO(III)?

  1. I > II > III
  2. I > III > II
  3. III > II > I
  4. II > III > I

Question’s Answer: II > III > I

___________is not a reaction of enolic form of acetoacetic ester.

  1. Coloration with FeCl3
  2. Addition of bromine
  3. Acetylation
  4. Reaction with HCN

Question’s Answer: Reaction with HCN

Ethyl acetoacetate when boiled with aqueous KOH undergoes hydrolysis to form mainly ________ .

  2. CH3COOH
  3. CH3 CO CH3

Question’s Answer: CH3 CO CH3

Which is form after Reaction of ethyl acetoacetate with phenyl hydrazine?

  1. Methyl isoxazolone
  2. Methyl isoxapyrazolone
  3. 3-Methyl-1-phenylpyrazolone
  4. Dimethyl phenyl oxazolone

Question’s Answer: 3-Methyl-1-phenylpyrazolone

Ethyl acetoacetate may be used to prepare

  1. Ketonic acids
  2. Ketones
  3. Carboxylic acids
  4. All A, B, and C

Question’s Answer: All A, B, and C

Which of the following can be formed by Reaction of sodium ethoxide with malonic ester?

  1. Resonance stabilized free radical
  2. Resonance stabilized cation
  3. Resonance stabilized anion
  4. Resonance stabilized electrophile

Question’s Answer: Resonance stabilized anion

Succinic acid may be obtained from sodiumalonic ester by its reaction with ______ by hydrolysis.

  1. R-X
  2. Dil.HCl
  3. Alc.KOH
  4. I2

Question’s Answer: I2

A reactive methylene group is a methylene group present between what kind of groups.

  1. Electron donating groups
  2. Carbonyl groups
  3. Hydroxyl groups
  4. Amino groups

Question’s Answer: Carbonyl groups

Which is not a reactive methylene compound?

  3. C2H500CCH2COOC2H5

Question’s Answer: C2H5OOCCH2CH2NH2

Which is the compound which exhibits keto-enol tautomerism?

  2. C₂H5O OCCH₂NO₂
  4. C₂H5O OC CH₂CN

Question’s Answer: C₂H5O OC CH₂COCH

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