Chapter
stringclasses 18
values | sentence_range
stringlengths 3
9
| Text
stringlengths 7
7.34k
|
|---|---|---|
1 | 7205-7208 | Basic character of amines can be better understood in terms of their Kb
and pKb values as explained below:
K =
3
2
2
R
OH
R
H
NH
NH
O
2
or
K[H O]
=
3
2
O
H
N H
H
R
R
N
or
Kb
=
3
2
O
N H
NH
H
R
R
pKb = –log Kb
Larger the value of Kb or smaller the value of pKb, stronger is the
base The pKb values of few amines are given in Table 9 3 pKb value of ammonia is 4 |
1 | 7206-7209 | The pKb values of few amines are given in Table 9 3 pKb value of ammonia is 4 75 |
1 | 7207-7210 | 3 pKb value of ammonia is 4 75 Aliphatic amines are stronger bases
than ammonia due to +I effect of alkyl groups leading to high electron
density on the nitrogen atom |
1 | 7208-7211 | pKb value of ammonia is 4 75 Aliphatic amines are stronger bases
than ammonia due to +I effect of alkyl groups leading to high electron
density on the nitrogen atom Their pKb values lie in the range of 3 to
4 |
1 | 7209-7212 | 75 Aliphatic amines are stronger bases
than ammonia due to +I effect of alkyl groups leading to high electron
density on the nitrogen atom Their pKb values lie in the range of 3 to
4 22 |
1 | 7210-7213 | Aliphatic amines are stronger bases
than ammonia due to +I effect of alkyl groups leading to high electron
density on the nitrogen atom Their pKb values lie in the range of 3 to
4 22 On the other hand, aromatic amines are weaker bases than
ammonia due to the electron withdrawing nature of the aryl group |
1 | 7211-7214 | Their pKb values lie in the range of 3 to
4 22 On the other hand, aromatic amines are weaker bases than
ammonia due to the electron withdrawing nature of the aryl group Name of amine
pKb
Methanamine
3 |
1 | 7212-7215 | 22 On the other hand, aromatic amines are weaker bases than
ammonia due to the electron withdrawing nature of the aryl group Name of amine
pKb
Methanamine
3 38
N-Methylmethanamine
3 |
1 | 7213-7216 | On the other hand, aromatic amines are weaker bases than
ammonia due to the electron withdrawing nature of the aryl group Name of amine
pKb
Methanamine
3 38
N-Methylmethanamine
3 27
N,N-Dimethylmethanamine
4 |
1 | 7214-7217 | Name of amine
pKb
Methanamine
3 38
N-Methylmethanamine
3 27
N,N-Dimethylmethanamine
4 22
Ethanamine
3 |
1 | 7215-7218 | 38
N-Methylmethanamine
3 27
N,N-Dimethylmethanamine
4 22
Ethanamine
3 29
N-Ethylethanamine
3 |
1 | 7216-7219 | 27
N,N-Dimethylmethanamine
4 22
Ethanamine
3 29
N-Ethylethanamine
3 00
N,N-Diethylethanamine
3 |
1 | 7217-7220 | 22
Ethanamine
3 29
N-Ethylethanamine
3 00
N,N-Diethylethanamine
3 25
Benzenamine
9 |
1 | 7218-7221 | 29
N-Ethylethanamine
3 00
N,N-Diethylethanamine
3 25
Benzenamine
9 38
Phenylmethanamine
4 |
1 | 7219-7222 | 00
N,N-Diethylethanamine
3 25
Benzenamine
9 38
Phenylmethanamine
4 70
N-Methylaniline
9 |
1 | 7220-7223 | 25
Benzenamine
9 38
Phenylmethanamine
4 70
N-Methylaniline
9 30
N,N-Dimethylaniline
8 |
1 | 7221-7224 | 38
Phenylmethanamine
4 70
N-Methylaniline
9 30
N,N-Dimethylaniline
8 92
Table 9 |
1 | 7222-7225 | 70
N-Methylaniline
9 30
N,N-Dimethylaniline
8 92
Table 9 3: pKb Values of Amines in Aqueous Phase
Rationalised 2023-24
268
Chemistry
You may find some discrepancies while trying to interpret the Kb
values of amines on the basis of +I or –I effect of the substituents
present in amines |
1 | 7223-7226 | 30
N,N-Dimethylaniline
8 92
Table 9 3: pKb Values of Amines in Aqueous Phase
Rationalised 2023-24
268
Chemistry
You may find some discrepancies while trying to interpret the Kb
values of amines on the basis of +I or –I effect of the substituents
present in amines Besides inductive effect, there are other effects like
solvation effect, steric hinderance, etc |
1 | 7224-7227 | 92
Table 9 3: pKb Values of Amines in Aqueous Phase
Rationalised 2023-24
268
Chemistry
You may find some discrepancies while trying to interpret the Kb
values of amines on the basis of +I or –I effect of the substituents
present in amines Besides inductive effect, there are other effects like
solvation effect, steric hinderance, etc , which affect the basic strength
of amines |
1 | 7225-7228 | 3: pKb Values of Amines in Aqueous Phase
Rationalised 2023-24
268
Chemistry
You may find some discrepancies while trying to interpret the Kb
values of amines on the basis of +I or –I effect of the substituents
present in amines Besides inductive effect, there are other effects like
solvation effect, steric hinderance, etc , which affect the basic strength
of amines Just ponder over |
1 | 7226-7229 | Besides inductive effect, there are other effects like
solvation effect, steric hinderance, etc , which affect the basic strength
of amines Just ponder over You may get the answer in the following
paragraphs |
1 | 7227-7230 | , which affect the basic strength
of amines Just ponder over You may get the answer in the following
paragraphs Structure-basicity relationship of amines
Basicity of amines is related to their structure |
1 | 7228-7231 | Just ponder over You may get the answer in the following
paragraphs Structure-basicity relationship of amines
Basicity of amines is related to their structure Basic character of an
amine depends upon the ease of formation of the cation by accepting
a proton from the acid |
1 | 7229-7232 | You may get the answer in the following
paragraphs Structure-basicity relationship of amines
Basicity of amines is related to their structure Basic character of an
amine depends upon the ease of formation of the cation by accepting
a proton from the acid The more stable the cation is relative to the
amine, more basic is the amine |
1 | 7230-7233 | Structure-basicity relationship of amines
Basicity of amines is related to their structure Basic character of an
amine depends upon the ease of formation of the cation by accepting
a proton from the acid The more stable the cation is relative to the
amine, more basic is the amine (a) Alkanamines versus ammonia
Let us consider the reaction of an alkanamine and ammonia with
a proton to compare their basicity |
1 | 7231-7234 | Basic character of an
amine depends upon the ease of formation of the cation by accepting
a proton from the acid The more stable the cation is relative to the
amine, more basic is the amine (a) Alkanamines versus ammonia
Let us consider the reaction of an alkanamine and ammonia with
a proton to compare their basicity Due to the electron releasing nature of alkyl group, it (R) pushes
electrons towards nitrogen and thus makes the unshared electron
pair more available for sharing with the proton of the acid |
1 | 7232-7235 | The more stable the cation is relative to the
amine, more basic is the amine (a) Alkanamines versus ammonia
Let us consider the reaction of an alkanamine and ammonia with
a proton to compare their basicity Due to the electron releasing nature of alkyl group, it (R) pushes
electrons towards nitrogen and thus makes the unshared electron
pair more available for sharing with the proton of the acid Moreover,
the substituted ammonium ion formed from the amine gets stabilised
due to dispersal of the positive charge by the +I effect of the alkyl
group |
1 | 7233-7236 | (a) Alkanamines versus ammonia
Let us consider the reaction of an alkanamine and ammonia with
a proton to compare their basicity Due to the electron releasing nature of alkyl group, it (R) pushes
electrons towards nitrogen and thus makes the unshared electron
pair more available for sharing with the proton of the acid Moreover,
the substituted ammonium ion formed from the amine gets stabilised
due to dispersal of the positive charge by the +I effect of the alkyl
group Hence, alkylamines are stronger bases than ammonia |
1 | 7234-7237 | Due to the electron releasing nature of alkyl group, it (R) pushes
electrons towards nitrogen and thus makes the unshared electron
pair more available for sharing with the proton of the acid Moreover,
the substituted ammonium ion formed from the amine gets stabilised
due to dispersal of the positive charge by the +I effect of the alkyl
group Hence, alkylamines are stronger bases than ammonia Thus, the basic nature of aliphatic amines should increase with
increase in the number of alkyl groups |
1 | 7235-7238 | Moreover,
the substituted ammonium ion formed from the amine gets stabilised
due to dispersal of the positive charge by the +I effect of the alkyl
group Hence, alkylamines are stronger bases than ammonia Thus, the basic nature of aliphatic amines should increase with
increase in the number of alkyl groups This trend is followed in
the gaseous phase |
1 | 7236-7239 | Hence, alkylamines are stronger bases than ammonia Thus, the basic nature of aliphatic amines should increase with
increase in the number of alkyl groups This trend is followed in
the gaseous phase The order of basicity of amines in the gaseous
phase follows the expected order: tertiary amine > secondary amine
> primary amine > NH3 |
1 | 7237-7240 | Thus, the basic nature of aliphatic amines should increase with
increase in the number of alkyl groups This trend is followed in
the gaseous phase The order of basicity of amines in the gaseous
phase follows the expected order: tertiary amine > secondary amine
> primary amine > NH3 The trend is not regular in the aqueous
state as evident by their pKb values given in Table 9 |
1 | 7238-7241 | This trend is followed in
the gaseous phase The order of basicity of amines in the gaseous
phase follows the expected order: tertiary amine > secondary amine
> primary amine > NH3 The trend is not regular in the aqueous
state as evident by their pKb values given in Table 9 3 |
1 | 7239-7242 | The order of basicity of amines in the gaseous
phase follows the expected order: tertiary amine > secondary amine
> primary amine > NH3 The trend is not regular in the aqueous
state as evident by their pKb values given in Table 9 3 In the
aqueous phase, the substituted ammonium cations get stabilised
not only by electron releasing effect of the alkyl group (+I) but also
by solvation with water molecules |
1 | 7240-7243 | The trend is not regular in the aqueous
state as evident by their pKb values given in Table 9 3 In the
aqueous phase, the substituted ammonium cations get stabilised
not only by electron releasing effect of the alkyl group (+I) but also
by solvation with water molecules The greater the size of the ion,
lesser will be the solvation and the less stabilised is the ion |
1 | 7241-7244 | 3 In the
aqueous phase, the substituted ammonium cations get stabilised
not only by electron releasing effect of the alkyl group (+I) but also
by solvation with water molecules The greater the size of the ion,
lesser will be the solvation and the less stabilised is the ion The
order of stability of ions are as follows:
Decreasing order of extent of H-bonding in water and order of
stability of ions by solvation |
1 | 7242-7245 | In the
aqueous phase, the substituted ammonium cations get stabilised
not only by electron releasing effect of the alkyl group (+I) but also
by solvation with water molecules The greater the size of the ion,
lesser will be the solvation and the less stabilised is the ion The
order of stability of ions are as follows:
Decreasing order of extent of H-bonding in water and order of
stability of ions by solvation Rationalised 2023-24
269
Amines
Greater is the stability of the substituted ammonium cation, stronger
should be the corresponding amine as a base |
1 | 7243-7246 | The greater the size of the ion,
lesser will be the solvation and the less stabilised is the ion The
order of stability of ions are as follows:
Decreasing order of extent of H-bonding in water and order of
stability of ions by solvation Rationalised 2023-24
269
Amines
Greater is the stability of the substituted ammonium cation, stronger
should be the corresponding amine as a base Thus, the order of basicity
of aliphatic amines should be: primary > secondary > tertiary, which
is opposite to the inductive effect based order |
1 | 7244-7247 | The
order of stability of ions are as follows:
Decreasing order of extent of H-bonding in water and order of
stability of ions by solvation Rationalised 2023-24
269
Amines
Greater is the stability of the substituted ammonium cation, stronger
should be the corresponding amine as a base Thus, the order of basicity
of aliphatic amines should be: primary > secondary > tertiary, which
is opposite to the inductive effect based order Secondly, when the
alkyl group is small, like –CH3 group, there is no steric hindrance to
H-bonding |
1 | 7245-7248 | Rationalised 2023-24
269
Amines
Greater is the stability of the substituted ammonium cation, stronger
should be the corresponding amine as a base Thus, the order of basicity
of aliphatic amines should be: primary > secondary > tertiary, which
is opposite to the inductive effect based order Secondly, when the
alkyl group is small, like –CH3 group, there is no steric hindrance to
H-bonding In case the alkyl group is bigger than CH3 group, there will
be steric hinderance to H-bonding |
1 | 7246-7249 | Thus, the order of basicity
of aliphatic amines should be: primary > secondary > tertiary, which
is opposite to the inductive effect based order Secondly, when the
alkyl group is small, like –CH3 group, there is no steric hindrance to
H-bonding In case the alkyl group is bigger than CH3 group, there will
be steric hinderance to H-bonding Therefore, the change of nature of
the alkyl group, e |
1 | 7247-7250 | Secondly, when the
alkyl group is small, like –CH3 group, there is no steric hindrance to
H-bonding In case the alkyl group is bigger than CH3 group, there will
be steric hinderance to H-bonding Therefore, the change of nature of
the alkyl group, e g |
1 | 7248-7251 | In case the alkyl group is bigger than CH3 group, there will
be steric hinderance to H-bonding Therefore, the change of nature of
the alkyl group, e g , from –CH3 to –C2H5 results in change of the order
of basic strength |
1 | 7249-7252 | Therefore, the change of nature of
the alkyl group, e g , from –CH3 to –C2H5 results in change of the order
of basic strength Thus, there is a subtle interplay of the inductive
effect, solvation effect and steric hinderance of the alkyl group which
decides the basic strength of alkyl amines in the aqueous state |
1 | 7250-7253 | g , from –CH3 to –C2H5 results in change of the order
of basic strength Thus, there is a subtle interplay of the inductive
effect, solvation effect and steric hinderance of the alkyl group which
decides the basic strength of alkyl amines in the aqueous state The
order of basic strength in case of methyl substituted amines and ethyl
substituted amines in aqueous solution is as follows:
(C2H5)2NH > (C2H5)3N > C2H5NH2 > NH3
(CH3)2NH > CH3NH2 > (CH3)3N > NH3
(b) Arylamines versus ammonia
pKb value of aniline is quite high |
1 | 7251-7254 | , from –CH3 to –C2H5 results in change of the order
of basic strength Thus, there is a subtle interplay of the inductive
effect, solvation effect and steric hinderance of the alkyl group which
decides the basic strength of alkyl amines in the aqueous state The
order of basic strength in case of methyl substituted amines and ethyl
substituted amines in aqueous solution is as follows:
(C2H5)2NH > (C2H5)3N > C2H5NH2 > NH3
(CH3)2NH > CH3NH2 > (CH3)3N > NH3
(b) Arylamines versus ammonia
pKb value of aniline is quite high Why is it so |
1 | 7252-7255 | Thus, there is a subtle interplay of the inductive
effect, solvation effect and steric hinderance of the alkyl group which
decides the basic strength of alkyl amines in the aqueous state The
order of basic strength in case of methyl substituted amines and ethyl
substituted amines in aqueous solution is as follows:
(C2H5)2NH > (C2H5)3N > C2H5NH2 > NH3
(CH3)2NH > CH3NH2 > (CH3)3N > NH3
(b) Arylamines versus ammonia
pKb value of aniline is quite high Why is it so It is because in
aniline or other arylamines, the -NH2 group is attached directly to
the benzene ring |
1 | 7253-7256 | The
order of basic strength in case of methyl substituted amines and ethyl
substituted amines in aqueous solution is as follows:
(C2H5)2NH > (C2H5)3N > C2H5NH2 > NH3
(CH3)2NH > CH3NH2 > (CH3)3N > NH3
(b) Arylamines versus ammonia
pKb value of aniline is quite high Why is it so It is because in
aniline or other arylamines, the -NH2 group is attached directly to
the benzene ring It results in the unshared electron pair on nitrogen
atom to be in conjugation with the benzene ring and thus making
it less available for protonation |
1 | 7254-7257 | Why is it so It is because in
aniline or other arylamines, the -NH2 group is attached directly to
the benzene ring It results in the unshared electron pair on nitrogen
atom to be in conjugation with the benzene ring and thus making
it less available for protonation If you write different resonating
structures of aniline, you will find that aniline is a resonance
hybrid of the following five structures |
1 | 7255-7258 | It is because in
aniline or other arylamines, the -NH2 group is attached directly to
the benzene ring It results in the unshared electron pair on nitrogen
atom to be in conjugation with the benzene ring and thus making
it less available for protonation If you write different resonating
structures of aniline, you will find that aniline is a resonance
hybrid of the following five structures On the other hand, anilinium ion obtained by accepting a proton
can have only two resonating structures (kekule) |
1 | 7256-7259 | It results in the unshared electron pair on nitrogen
atom to be in conjugation with the benzene ring and thus making
it less available for protonation If you write different resonating
structures of aniline, you will find that aniline is a resonance
hybrid of the following five structures On the other hand, anilinium ion obtained by accepting a proton
can have only two resonating structures (kekule) We know that greater the number of resonating structures, greater
is the stability |
1 | 7257-7260 | If you write different resonating
structures of aniline, you will find that aniline is a resonance
hybrid of the following five structures On the other hand, anilinium ion obtained by accepting a proton
can have only two resonating structures (kekule) We know that greater the number of resonating structures, greater
is the stability Thus you can infer that aniline (five resonating
structures) is more stable than anilinium ion |
1 | 7258-7261 | On the other hand, anilinium ion obtained by accepting a proton
can have only two resonating structures (kekule) We know that greater the number of resonating structures, greater
is the stability Thus you can infer that aniline (five resonating
structures) is more stable than anilinium ion Hence, the proton
acceptability or the basic nature of aniline or other aromatic amines
would be less than that of ammonia |
1 | 7259-7262 | We know that greater the number of resonating structures, greater
is the stability Thus you can infer that aniline (five resonating
structures) is more stable than anilinium ion Hence, the proton
acceptability or the basic nature of aniline or other aromatic amines
would be less than that of ammonia In case of substituted aniline, it
is observed that electron releasing groups like –OCH3, –CH3 increase
basic strength whereas electron withdrawing groups like –NO2, –SO3H,
–COOH, –X decrease it |
1 | 7260-7263 | Thus you can infer that aniline (five resonating
structures) is more stable than anilinium ion Hence, the proton
acceptability or the basic nature of aniline or other aromatic amines
would be less than that of ammonia In case of substituted aniline, it
is observed that electron releasing groups like –OCH3, –CH3 increase
basic strength whereas electron withdrawing groups like –NO2, –SO3H,
–COOH, –X decrease it Rationalised 2023-24
270
Chemistry
2 |
1 | 7261-7264 | Hence, the proton
acceptability or the basic nature of aniline or other aromatic amines
would be less than that of ammonia In case of substituted aniline, it
is observed that electron releasing groups like –OCH3, –CH3 increase
basic strength whereas electron withdrawing groups like –NO2, –SO3H,
–COOH, –X decrease it Rationalised 2023-24
270
Chemistry
2 Alkylation
Amines undergo alkylation on reaction with alkyl halides (refer Unit
6, Class XII) |
1 | 7262-7265 | In case of substituted aniline, it
is observed that electron releasing groups like –OCH3, –CH3 increase
basic strength whereas electron withdrawing groups like –NO2, –SO3H,
–COOH, –X decrease it Rationalised 2023-24
270
Chemistry
2 Alkylation
Amines undergo alkylation on reaction with alkyl halides (refer Unit
6, Class XII) 3 |
1 | 7263-7266 | Rationalised 2023-24
270
Chemistry
2 Alkylation
Amines undergo alkylation on reaction with alkyl halides (refer Unit
6, Class XII) 3 Acylation
Aliphatic and aromatic primary and secondary amines react with
acid chlorides, anhydrides and esters by nucleophilic substitution
reaction |
1 | 7264-7267 | Alkylation
Amines undergo alkylation on reaction with alkyl halides (refer Unit
6, Class XII) 3 Acylation
Aliphatic and aromatic primary and secondary amines react with
acid chlorides, anhydrides and esters by nucleophilic substitution
reaction This reaction is known as acylation |
1 | 7265-7268 | 3 Acylation
Aliphatic and aromatic primary and secondary amines react with
acid chlorides, anhydrides and esters by nucleophilic substitution
reaction This reaction is known as acylation You can consider
this reaction as the replacement of hydrogen atom of –NH2 or >N–H
group by the acyl group |
1 | 7266-7269 | Acylation
Aliphatic and aromatic primary and secondary amines react with
acid chlorides, anhydrides and esters by nucleophilic substitution
reaction This reaction is known as acylation You can consider
this reaction as the replacement of hydrogen atom of –NH2 or >N–H
group by the acyl group The products obtained by acylation reaction
are known as amides |
1 | 7267-7270 | This reaction is known as acylation You can consider
this reaction as the replacement of hydrogen atom of –NH2 or >N–H
group by the acyl group The products obtained by acylation reaction
are known as amides The reaction is carried out in the presence of
a base stronger than the amine, like pyridine, which removes HCl so
formed and shifts the equilibrium to the right hand side |
1 | 7268-7271 | You can consider
this reaction as the replacement of hydrogen atom of –NH2 or >N–H
group by the acyl group The products obtained by acylation reaction
are known as amides The reaction is carried out in the presence of
a base stronger than the amine, like pyridine, which removes HCl so
formed and shifts the equilibrium to the right hand side Amines also react with benzoyl chloride (C6H5COCl) |
1 | 7269-7272 | The products obtained by acylation reaction
are known as amides The reaction is carried out in the presence of
a base stronger than the amine, like pyridine, which removes HCl so
formed and shifts the equilibrium to the right hand side Amines also react with benzoyl chloride (C6H5COCl) This reaction
is known as benzoylation |
1 | 7270-7273 | The reaction is carried out in the presence of
a base stronger than the amine, like pyridine, which removes HCl so
formed and shifts the equilibrium to the right hand side Amines also react with benzoyl chloride (C6H5COCl) This reaction
is known as benzoylation 3
6
5
6
5
2
3
Methanamine
Benzoyl chloride
N
Methylbenzamide
NH
C C
O
CH
C H
CH
C H
H l
NH
l
C
C
O
What do you think is the product of the reaction of amines with
carboxylic acids |
1 | 7271-7274 | Amines also react with benzoyl chloride (C6H5COCl) This reaction
is known as benzoylation 3
6
5
6
5
2
3
Methanamine
Benzoyl chloride
N
Methylbenzamide
NH
C C
O
CH
C H
CH
C H
H l
NH
l
C
C
O
What do you think is the product of the reaction of amines with
carboxylic acids They form salts with amines at room temperature |
1 | 7272-7275 | This reaction
is known as benzoylation 3
6
5
6
5
2
3
Methanamine
Benzoyl chloride
N
Methylbenzamide
NH
C C
O
CH
C H
CH
C H
H l
NH
l
C
C
O
What do you think is the product of the reaction of amines with
carboxylic acids They form salts with amines at room temperature Arrange the following in decreasing order of their basic strength:
C6H5NH2, C2H5NH2, (C2H5)2NH, NH3
The decreasing order of basic strength of the above amines and ammonia
follows the following order:
(C2H5)2NH > C2H5NH2 > NH3 > C6H5NH2
Example 9 |
1 | 7273-7276 | 3
6
5
6
5
2
3
Methanamine
Benzoyl chloride
N
Methylbenzamide
NH
C C
O
CH
C H
CH
C H
H l
NH
l
C
C
O
What do you think is the product of the reaction of amines with
carboxylic acids They form salts with amines at room temperature Arrange the following in decreasing order of their basic strength:
C6H5NH2, C2H5NH2, (C2H5)2NH, NH3
The decreasing order of basic strength of the above amines and ammonia
follows the following order:
(C2H5)2NH > C2H5NH2 > NH3 > C6H5NH2
Example 9 4
Example 9 |
1 | 7274-7277 | They form salts with amines at room temperature Arrange the following in decreasing order of their basic strength:
C6H5NH2, C2H5NH2, (C2H5)2NH, NH3
The decreasing order of basic strength of the above amines and ammonia
follows the following order:
(C2H5)2NH > C2H5NH2 > NH3 > C6H5NH2
Example 9 4
Example 9 4
Example 9 |
1 | 7275-7278 | Arrange the following in decreasing order of their basic strength:
C6H5NH2, C2H5NH2, (C2H5)2NH, NH3
The decreasing order of basic strength of the above amines and ammonia
follows the following order:
(C2H5)2NH > C2H5NH2 > NH3 > C6H5NH2
Example 9 4
Example 9 4
Example 9 4
Example 9 |
1 | 7276-7279 | 4
Example 9 4
Example 9 4
Example 9 4
Example 9 |
1 | 7277-7280 | 4
Example 9 4
Example 9 4
Example 9 4
Solution
Solution
Solution
Solution
Solution
Rationalised 2023-24
271
Amines
S
O
O
Cl
+
H
N
C H
2
5
S
O
O
N
C H
2
5 + HCl
N,N-Diethylbenzenesulphonamide
C H
2
5
C H
2
5
4 |
1 | 7278-7281 | 4
Example 9 4
Example 9 4
Solution
Solution
Solution
Solution
Solution
Rationalised 2023-24
271
Amines
S
O
O
Cl
+
H
N
C H
2
5
S
O
O
N
C H
2
5 + HCl
N,N-Diethylbenzenesulphonamide
C H
2
5
C H
2
5
4 Carbylamine reaction
Aliphatic and aromatic primary amines on heating with chloroform
and ethanolic potassium hydroxide form isocyanides or carbylamines
which are foul smelling substances |
1 | 7279-7282 | 4
Example 9 4
Solution
Solution
Solution
Solution
Solution
Rationalised 2023-24
271
Amines
S
O
O
Cl
+
H
N
C H
2
5
S
O
O
N
C H
2
5 + HCl
N,N-Diethylbenzenesulphonamide
C H
2
5
C H
2
5
4 Carbylamine reaction
Aliphatic and aromatic primary amines on heating with chloroform
and ethanolic potassium hydroxide form isocyanides or carbylamines
which are foul smelling substances Secondary and tertiary amines
do not show this reaction |
1 | 7280-7283 | 4
Solution
Solution
Solution
Solution
Solution
Rationalised 2023-24
271
Amines
S
O
O
Cl
+
H
N
C H
2
5
S
O
O
N
C H
2
5 + HCl
N,N-Diethylbenzenesulphonamide
C H
2
5
C H
2
5
4 Carbylamine reaction
Aliphatic and aromatic primary amines on heating with chloroform
and ethanolic potassium hydroxide form isocyanides or carbylamines
which are foul smelling substances Secondary and tertiary amines
do not show this reaction This reaction is known as carbylamine
reaction or isocyanide test and is used as a test for primary amines |
1 | 7281-7284 | Carbylamine reaction
Aliphatic and aromatic primary amines on heating with chloroform
and ethanolic potassium hydroxide form isocyanides or carbylamines
which are foul smelling substances Secondary and tertiary amines
do not show this reaction This reaction is known as carbylamine
reaction or isocyanide test and is used as a test for primary amines 5 |
1 | 7282-7285 | Secondary and tertiary amines
do not show this reaction This reaction is known as carbylamine
reaction or isocyanide test and is used as a test for primary amines 5 Reaction with nitrous acid
Three classes of amines react differently with nitrous acid which is
prepared in situ from a mineral acid and sodium nitrite |
1 | 7283-7286 | This reaction is known as carbylamine
reaction or isocyanide test and is used as a test for primary amines 5 Reaction with nitrous acid
Three classes of amines react differently with nitrous acid which is
prepared in situ from a mineral acid and sodium nitrite (a) Primary aliphatic amines react with nitrous acid to form aliphatic
diazonium salts which being unstable, liberate nitrogen gas
quantitatively and alcohols |
1 | 7284-7287 | 5 Reaction with nitrous acid
Three classes of amines react differently with nitrous acid which is
prepared in situ from a mineral acid and sodium nitrite (a) Primary aliphatic amines react with nitrous acid to form aliphatic
diazonium salts which being unstable, liberate nitrogen gas
quantitatively and alcohols Quantitative evolution of nitrogen is
used in estimation of amino acids and proteins |
1 | 7285-7288 | Reaction with nitrous acid
Three classes of amines react differently with nitrous acid which is
prepared in situ from a mineral acid and sodium nitrite (a) Primary aliphatic amines react with nitrous acid to form aliphatic
diazonium salts which being unstable, liberate nitrogen gas
quantitatively and alcohols Quantitative evolution of nitrogen is
used in estimation of amino acids and proteins (b) Aromatic amines react with nitrous acid at low temperatures
(273-278 K) to form diazonium salts, a very important class of
compounds used for synthesis of a variety of aromatic compounds
discussed in Section 9 |
1 | 7286-7289 | (a) Primary aliphatic amines react with nitrous acid to form aliphatic
diazonium salts which being unstable, liberate nitrogen gas
quantitatively and alcohols Quantitative evolution of nitrogen is
used in estimation of amino acids and proteins (b) Aromatic amines react with nitrous acid at low temperatures
(273-278 K) to form diazonium salts, a very important class of
compounds used for synthesis of a variety of aromatic compounds
discussed in Section 9 7 |
1 | 7287-7290 | Quantitative evolution of nitrogen is
used in estimation of amino acids and proteins (b) Aromatic amines react with nitrous acid at low temperatures
(273-278 K) to form diazonium salts, a very important class of
compounds used for synthesis of a variety of aromatic compounds
discussed in Section 9 7 Secondary and tertiary amines react with nitrous acid in a
different manner |
1 | 7288-7291 | (b) Aromatic amines react with nitrous acid at low temperatures
(273-278 K) to form diazonium salts, a very important class of
compounds used for synthesis of a variety of aromatic compounds
discussed in Section 9 7 Secondary and tertiary amines react with nitrous acid in a
different manner 6 |
1 | 7289-7292 | 7 Secondary and tertiary amines react with nitrous acid in a
different manner 6 Reaction with arylsulphonyl chloride
Benzenesulphonyl chloride (C6H5SO2Cl), which is also known as
Hinsberg’s reagent, reacts with primary and secondary amines to
form sulphonamides |
1 | 7290-7293 | Secondary and tertiary amines react with nitrous acid in a
different manner 6 Reaction with arylsulphonyl chloride
Benzenesulphonyl chloride (C6H5SO2Cl), which is also known as
Hinsberg’s reagent, reacts with primary and secondary amines to
form sulphonamides (a) The reaction of benzenesulphonyl chloride with primary amine
yields N-ethylbenzenesulphonyl amide |
1 | 7291-7294 | 6 Reaction with arylsulphonyl chloride
Benzenesulphonyl chloride (C6H5SO2Cl), which is also known as
Hinsberg’s reagent, reacts with primary and secondary amines to
form sulphonamides (a) The reaction of benzenesulphonyl chloride with primary amine
yields N-ethylbenzenesulphonyl amide The hydrogen attached to nitrogen in sulphonamide is strongly
acidic due to the presence of strong electron withdrawing sulphonyl
group |
1 | 7292-7295 | Reaction with arylsulphonyl chloride
Benzenesulphonyl chloride (C6H5SO2Cl), which is also known as
Hinsberg’s reagent, reacts with primary and secondary amines to
form sulphonamides (a) The reaction of benzenesulphonyl chloride with primary amine
yields N-ethylbenzenesulphonyl amide The hydrogen attached to nitrogen in sulphonamide is strongly
acidic due to the presence of strong electron withdrawing sulphonyl
group Hence, it is soluble in alkali |
1 | 7293-7296 | (a) The reaction of benzenesulphonyl chloride with primary amine
yields N-ethylbenzenesulphonyl amide The hydrogen attached to nitrogen in sulphonamide is strongly
acidic due to the presence of strong electron withdrawing sulphonyl
group Hence, it is soluble in alkali (b) In the reaction with secondary amine, N,N-diethyl-
benzenesulphonamide is formed |
1 | 7294-7297 | The hydrogen attached to nitrogen in sulphonamide is strongly
acidic due to the presence of strong electron withdrawing sulphonyl
group Hence, it is soluble in alkali (b) In the reaction with secondary amine, N,N-diethyl-
benzenesulphonamide is formed Rationalised 2023-24
272
Chemistry
Since N, N-diethylbenzene sulphonamide does not contain any
hydrogen atom attached to nitrogen atom, it is not acidic and hence
insoluble in alkali |
1 | 7295-7298 | Hence, it is soluble in alkali (b) In the reaction with secondary amine, N,N-diethyl-
benzenesulphonamide is formed Rationalised 2023-24
272
Chemistry
Since N, N-diethylbenzene sulphonamide does not contain any
hydrogen atom attached to nitrogen atom, it is not acidic and hence
insoluble in alkali (c) Tertiary amines do not react with benzenesulphonyl chloride |
1 | 7296-7299 | (b) In the reaction with secondary amine, N,N-diethyl-
benzenesulphonamide is formed Rationalised 2023-24
272
Chemistry
Since N, N-diethylbenzene sulphonamide does not contain any
hydrogen atom attached to nitrogen atom, it is not acidic and hence
insoluble in alkali (c) Tertiary amines do not react with benzenesulphonyl chloride This property of amines reacting with benzenesulphonyl chloride
in a different manner is used for the distinction of primary,
secondary and tertiary amines and also for the separation of a
mixture of amines |
1 | 7297-7300 | Rationalised 2023-24
272
Chemistry
Since N, N-diethylbenzene sulphonamide does not contain any
hydrogen atom attached to nitrogen atom, it is not acidic and hence
insoluble in alkali (c) Tertiary amines do not react with benzenesulphonyl chloride This property of amines reacting with benzenesulphonyl chloride
in a different manner is used for the distinction of primary,
secondary and tertiary amines and also for the separation of a
mixture of amines However, these days benzenesulphonyl
chloride is replaced by p-toluenesulphonyl chloride |
1 | 7298-7301 | (c) Tertiary amines do not react with benzenesulphonyl chloride This property of amines reacting with benzenesulphonyl chloride
in a different manner is used for the distinction of primary,
secondary and tertiary amines and also for the separation of a
mixture of amines However, these days benzenesulphonyl
chloride is replaced by p-toluenesulphonyl chloride 7 |
1 | 7299-7302 | This property of amines reacting with benzenesulphonyl chloride
in a different manner is used for the distinction of primary,
secondary and tertiary amines and also for the separation of a
mixture of amines However, these days benzenesulphonyl
chloride is replaced by p-toluenesulphonyl chloride 7 Electrophilic substitution
You have read earlier that aniline is a resonance hybrid of five
structures |
1 | 7300-7303 | However, these days benzenesulphonyl
chloride is replaced by p-toluenesulphonyl chloride 7 Electrophilic substitution
You have read earlier that aniline is a resonance hybrid of five
structures Where do you find the maximum electron density in
these structures |
1 | 7301-7304 | 7 Electrophilic substitution
You have read earlier that aniline is a resonance hybrid of five
structures Where do you find the maximum electron density in
these structures Ortho- and para-positions to the –NH2 group
become centres of high electron density |
1 | 7302-7305 | Electrophilic substitution
You have read earlier that aniline is a resonance hybrid of five
structures Where do you find the maximum electron density in
these structures Ortho- and para-positions to the –NH2 group
become centres of high electron density Thus –NH2 group is ortho
and para directing and a powerful activating group |
1 | 7303-7306 | Where do you find the maximum electron density in
these structures Ortho- and para-positions to the –NH2 group
become centres of high electron density Thus –NH2 group is ortho
and para directing and a powerful activating group (a) Bromination: Aniline reacts with bromine water at room
temperature to give a white precipitate of 2,4,6-tribromoaniline |
1 | 7304-7307 | Ortho- and para-positions to the –NH2 group
become centres of high electron density Thus –NH2 group is ortho
and para directing and a powerful activating group (a) Bromination: Aniline reacts with bromine water at room
temperature to give a white precipitate of 2,4,6-tribromoaniline The main problem encountered during electrophilic substitution
reactions of aromatic amines is that of their very high reactivity |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.