Curtius and Hofmann Rearrangements

Q. Which of the following compounds give a ketone with grignard reagent?

1. Formaldehyde
2. Ethyl alcohol
3. Methyl cyanide
4. Methyl iodide

Q.

How will you convert

(i) ethanoic acid into methanamine?

(ii) hexanenitrile into 1-aminopentane?

(iii) Methanol to ethanoic acid?

(iv) ethanamine into methanamine?

(v) Ethanoic acid into propanoic acid

(vi) Methanamine into ethanamine?

(vii) nitromethane into dimethylamine?

(viii) propanoic acid into ethanoic acid?

Q.

How to convert benzene into phenol?

Q.

Does NaBH4 reduces acid anhydride?

Q.

Gabriel phthalimide synthesis is used for the preparation of

1. Primary amines

2. Secondary amines

3. Tertiary amines

4. Quaternary amines

Q. Which of the following reactions is appropriate for converting acetamide to methanamine?

1. Carbylamine reaction
2. Hoffmann hypobromamide reaction
3. Gabriel-phthalimide synthesis
4. Stephen's reaction

Q.

Show how each of the following compounds can be converted to benzoic acid.

(i) Ethylbenzene (ii) Acetophenone

(iii) Bromobenzene (iv) Phenylethene (Styrene)

Q. Given below are two statements:
Statement-I : In Hofmann degradation reaction, the migration of only an alkyl group takes place from carbonyl carbon of the amide to the nitrogen atom.
Statement-II : The group is migrated in Hofmann degradation reaction to electron deficient atom. In the light of the above statements, choose the most appropriate answer from the options given below:

1. Statement I is correct but Statement II is incorrect
2. Both Statement I and Statement II are incorrect
3. Both Statement I and Statement II are correct
4. Statement I is incorrect but Statement II is correct

Q. In the Hofmann bromamide degradation reaction, the number of moles of $NaOH$ and $B{r}_2$ used per mole of amine produced are:

1. Four moles of $NaOH$ and two moles of $B{r}_2$.
2. Two moles of $NaOH$ and two moles of $B{r}_2$.
3. Four moles of $NaOH$ and one mole of $B{r}_2$.
4. One mole of $NaOH$ and one mole of $B{r}_2$

Q.

Name the reagent used in the following reaction Butan$-2-$one to Butan$-2-$ol

Q. Intermediate involved in Hoffmann Bromanide reaction is :

1. Carbene
2. Carbocation
3. nitrene
4. free radical

Q.

The total number of amines among the following which can be synthesized by Gabriel synthesis is

1. 

2. ${\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{NH}}_2$

3. 

4. 

Q.

Intermediates formed during the reaction RCONH₂ with Br₂ and KOH are

1. RCONBr₂

2. RNHCOBr and RNCO

3. RNH - Br and RNCO

4. RCONHBr and RNCO

Q.

How will you bring the conversion of Methyl Bromide to Acetone?

Q.

Which reaction can be used for the direct conversion of amides into 1⁰ amine ?

1. Hoffmann ammonolysis

2. Claissen reaction

3. Perkin's reaction

4. Reduction with LiAlH₄

Q. Can benzaldehyde be converted to benzoic acid using the tollens reagent

Q. An organic compound (A) with the molecular formula, $\left(C_7{H}_{8}O\right)$ dissolves in $NaOH$ and gives characteristics colour with neutral $FeC{l}_3$. On treatment with bromine water, it gives a tribromo derivative, $C_7{H}_{5}OB{r}_3$. The compound is:

1. p-cresol
2. o-cresol
3. m-cresol
4. benzyl alcohol

Q.

The amine formed from an amide by means of bromine and alkali has

1. Same number of C atoms as that of amide

2. One less C atom than that of amide

3. One more C atom than that of amide

4. Two more C atoms than that of amide

Q. Reaction of Acetamide with bromine water and KOH gives

1. $C{H}_{3}COOH$
2. $C{H}_{3}C{H}_{2}N{H}_2$
3. $C{H}_{3}COON{H}_4$
4. $C{H}_{3}N{H}_2$

Q. How many bidentate ligand required for an octahedral complex to show optical isomerism?

Q. Which of the following reactions is appropriate to convert acetamide to methanamine?

1. Stephen's reaction
2. Gabriel synthesis
3. Carbylamine reaction
4. Hofmann bromamide degradation

Q. 2, 5-Dimethylcyclo pentane -1, 1-dicarboxylic acid has x steroisomer out of which y are optically inactive. Mono decarboxylation of two isomer occurs as

Reaction - I
An optically active isomer $\stackrel{Heat}{⟶}$ product(s) + $C{O}_2$

Reaction II

An optically inactive isomer $\stackrel{Heat}{⟶}$ product(s) + $C{O}_2$

Select the correct statements(s).

1. $y=1$
2. In reaction I, single product is formed (enantiomer is not considered different compound)
3. In reaction II, two different isomeric products are formed
4. $x=3$

Q.

Acetamide changes into methylamine by

1. Hinsberg reaction

2. Hofmann bromamide reaction

3. Hofmann reaction

4. Friedel-Craft's reaction

Q.

In the following reactions the sum of the total number of atoms in one molecule of (A), (B) & (C) is

$$\begin{gathered} \mathrm{NaCl}+{\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7+{\mathrm{H}}_2{\mathrm{SO}}_4\to \left(\mathrm{A}\right)+\mathrm{side}\mathrm{products} \\ \left(\mathrm{A}\right)+\mathrm{NaOH}\to \left(\mathrm{B}\right)+\mathrm{side}\mathrm{products} \\ \left(\mathrm{B}\right)+{\mathrm{H}}_2{\mathrm{SO}}_4(\mathrm{dil}.)+{\mathrm{H}}_2{\mathrm{O}}_2\to \left(\mathrm{C}\right)+\mathrm{side}\mathrm{products} \end{gathered}$$

Q. why is HCOOH more acidic than benzoic acid?

Q. how many acids can be taken to obtain isobu†an e by decarboxylation

Q. 45 Mixture of carboxylic acid obtained by the oxidation of hexan-3-one does not yield ?? 1. Methanoic acid 2. Ethanoic acid 3. Propanoic acid 4. Butanoic acid

Q. Acetamide is treated separately with the following reagents. Which one of these would give methylamine?

1. ${PCl}_5$
2. Sodalime
3. $NaOH+{Br}_2$
4. Hot concentrated $H_2{SO}_4$

Q. Hoffmann degradation of m-bromobenzamide gives.

1. Aniline
2. m-Bromo aniline
3. Bromo benzene
4. m-Bromo ethyl benzene

Q.

When ${\mathrm{KMnO}}_4$ Reacts With${\mathrm{H}}_2{\mathrm{O}}_2$In Slightly Alkaline. Which of the following chemical element is formed?

1. ${\mathrm{MnO}}_2$

2. ${\mathrm{Mn}}^{+7}$

3. ${\mathrm{Mn}}^{+2}$

4. ${\mathrm{Mn}}_2{\mathrm{O}}_3$