Chemistry Of Organic Compounds

1. Used as an antiseptic in low concentrations.
2. Used in the production of plastics like Bakelite.
3. Intermediate in the synthesis of dyes and drugs.

A (secondary) amine has two alkyl or aryl groups attached to the nitrogen atom along with one hydrogen atom, represented as .

Step 1: Identify the longest carbon chain containing the aldehyde group. The parent chain contains 6 carbons, making it a hexanal. Step 2: Number the chain starting from the aldehyde functional group. A methyl group is attached to carbon 3. Step 3: The IUPAC name is:

Step 1: Complex compounds are used in qualitative analysis due to their selective reactivity with metal ions. Step 2: Example - Ammonia Complexation with Copper: This forms a deep blue solution, aiding in the detection of ions.

Resonating Structures of Arylamines: Arylamines, such as aniline ( ), exhibit resonance due to the delocalization of the lone pair of electrons on the nitrogen atom into the benzene ring. Basic Properties: Arylamines are basic because the lone pair of electrons on the nitrogen atom can accept a proton ( ). However, resonance decreases the availability of the lone pair, making them less basic than aliphatic amines. Preparation of Amines: 1. From Nitro Compounds: 2. From Nitriles:

- Elimination: Haloalkane reacts with to form an alkene. - Substitution: Haloalkane reacts with to form an alcohol.

(i) Rosenmund reduction:

- Chloroform (CHCl ) has three chlorine atoms attached to a central carbon, which makes the C-H bond in chloroform weak and more likely to be dissociated. When chloroform loses a proton (H ), it forms a trichloromethyl anion (CCl ). This hydrogen is acidic due to the inductive effect of the chlorine atoms. Chlorine is highly electronegative and pulls electron density away from the C-H bond, making the hydrogen more positive and easily removable. This is why chloroform exhibits acidic properties.

Optical activity:
A compound is said to be optically active if it can rotate the plane of plane-polarized light. Haloalkanes with a chiral carbon show optical activity.
Chirality:
A carbon atom bonded to four different groups is called a chiral carbon (asymmetric carbon). Such molecules exist in two non-superimposable mirror image forms (enantiomers).
Retention:
If during a reaction the spatial arrangement around the chiral carbon remains unchanged, the configuration is retained — this is called retention of configuration.
Inversion:
In mechanism, the nucleophile attacks from the backside, opposite to the leaving group. This flips the configuration at the chiral carbon, called Walden inversion.
Racemisation:
In mechanism, the planar carbocation formed can be attacked by the nucleophile from either side with equal probability. This gives a mixture of enantiomers (50:50), which is optically inactive due to mutual cancellation. This process is called racemisation.

(i) 2-Chloro-3-methylpentane
Condensed structure:
Main chain = pentane; Cl at C-2; methyl at C-3.
(ii) 1,4-Dibromobut-2-ene
Condensed structure:
But-2-ene backbone ( ); Br at C-1 and C-4.
(iii) 1-Bromo-2,2-dimethylpropane (neopentyl bromide)
Condensed structure:
Choose the propane chain ; Br at C-1; two groups at C-2.
(iv) 1-Bromo-2-methylbut-2-ene
Condensed structure:
But-2-ene backbone ( ); Br at C-1; methyl substituent at C-2.
(v) 1-Chloro-2-methylbenzene (o-chlorotoluene)
Aromatic structure: benzene ring with adjacent substituents at C-1 and at C-2.
Condensed/SMILES: .

Uses of Carbon Tetrachloride (CCl ):
\begin{itemize} \item Used as a cleaning agent for degreasing metals and machinery.
\item Acts as a solvent for oils, fats, and varnishes.
\item Earlier used in fire extinguishers (though avoided now due to toxicity).
\item Plays a role in the manufacture of refrigerants and propellants.
\end{itemize} Uses of Chloroform (CHCl ):
\begin{itemize} \item Widely used as a solvent in laboratories and industries.
\item Employed in the preparation of chlorofluorocarbons (CFCs).
\item Historically used as an anesthetic, though not common now due to harmful effects.
\item Helps in extraction and purification of alkaloids and other organic compounds.
\end{itemize}

(i) Decreasing order of value:
is inversely related to the basicity. A higher corresponds to a weaker base. The basicity of amines is influenced by the electron-donating ability of the substituents. The order from weakest to strongest base is:
- C H NHCH has the electron-donating methyl group attached to the nitrogen, slightly increasing basicity.
- C H NH has an ethyl group attached, which is more electron-donating than a phenyl group.
- C H NH has a phenyl group attached, which is electron-withdrawing, making it a weaker base.
(ii) Decreasing order of basic strength:
Basic strength is determined by the availability of the lone pair on nitrogen for protonation. The order from strongest to weakest base is:
- C H NH is the strongest base as the lone pair on nitrogen is readily available for protonation.
- C H N(CH ) has two methyl groups attached, making it more electron-donating, increasing basicity.
- C H NH has an electron-withdrawing phenyl group attached, making it the weakest base.
(iii) Increasing order of basic strength:
In the case of substituted anilines, electron-withdrawing substituents decrease basic strength. The order from weakest to strongest is:
- p-Nitroaniline has a nitro group ( ), which is electron-withdrawing, making it the weakest base.
- Aniline has no substituents, so it has a moderate basic strength.
- Paratoludine has a methyl group ( ), which is electron-donating, making it the strongest base.
(iv) Solubility order in water:
Amines with smaller alkyl groups are more soluble in water due to hydrogen bonding. The solubility order is:
- C H NH (aniline) is the most soluble in water due to the ability to form hydrogen bonds.
- ( ) NH (diethylamine) is less soluble due to the increased hydrophobic character of the ethyl groups.
- C H NH (ethylamine) has moderate solubility.
(v) Increasing order of boiling point:
The boiling points of amines increase with the size of the alkyl group and the ability to form hydrogen bonds. The order from lowest to highest boiling point is:
- C H OH (ethanol) has the lowest boiling point because it is a small molecule and only forms hydrogen bonds weakly.
- CH NH (methylamine) has a higher boiling point due to stronger hydrogen bonding.
- C H NH (ethylamine) has the highest boiling point because it has a larger molecular size and stronger hydrogen bonding.

This is a reaction of an alkyl group with cadmium, resulting in the formation of two molecules of ethyl chloride. The reaction is a dehalogenation and redistribution reaction.

(i) Propan-2-ol from propene:
Propene can be converted into propan-2-ol by hydration in the presence of a catalyst. The reaction is as follows: (ii) Benzyl alcohol from benzyl chloride:
Benzyl chloride can be converted into benzyl alcohol by hydrolysis, which involves a nucleophilic substitution reaction. The reaction is as follows: (iii) Propan-1-ol from ethyl magnesium chloride:
Ethyl magnesium chloride reacts with water (hydrolysis) to form propan-1-ol. The reaction is as follows: (iv) 2-methyl propan-2-ol from methyl magnesium bromide:
Methyl magnesium bromide reacts with water to form 2-methyl propan-2-ol. The reaction is as follows: (v) Picric acid from phenol:
Picric acid (2,4,6-trinitrophenol) can be synthesized from phenol by nitration with a mixture of concentrated nitric acid and sulfuric acid. The reaction is as follows:

(i) 1-phenylethanol from a suitable alkene:
1-phenylethanol can be synthesized from styrene (ethenylbenzene) by hydroboration-oxidation reaction. The reaction is as follows: (ii) Cyclohexylmethanol with the help of alkyl halide by SN2 reaction:
Cyclohexylmethanol can be synthesized by performing an SN2 reaction between cyclohexyl chloride and sodium hydroxide. The reaction is as follows: (iii) Pentan-1-ol from a suitable alkyl halide:
Pentan-1-ol can be synthesized from 1-bromopentane by a nucleophilic substitution reaction with sodium hydroxide. The reaction is as follows:

(i) sec-butyl chloride:
- Structural formula:
- IUPAC name: Butyl chloride (2-chlorobutane). This is the sec-butyl group, where the chlorine atom is attached to the second carbon of the butane chain.
(ii) isopentyl bromide:
- Structural formula:
- IUPAC name: Pentyl bromide (3-bromobutane). This is the isopentyl group, where the bromine atom is attached to the third carbon of the pentane chain.
(iii) tert-butyl chloride:
- Structural formula:
- IUPAC name: Butyl chloride (2-chloro-2-methylpropane). This is the tert-butyl group, where the chlorine atom is attached to the central carbon in the isopropyl group.
(iv) isobutyl chloride:
- Structural formula:
- IUPAC name: Butyl chloride (1-chlorobutane). This is the isobutyl group, where the chlorine atom is attached to the first carbon of the butane chain.
(v) neopentyl chloride:
- Structural formula:
- IUPAC name: Pentyl chloride (1-chloro-2-methylpropane). This is the neopentyl group, where the chlorine atom is attached to the first carbon of the chain.

(i) From ethyl iodide via nitrile and amide (Hofmann bromamide):
(ii) Sandmeyer to nitrile, hydrolysis to acid, then ammonolysis:
(iii) From bromoethane to nitrile, reduction to amine, then nitrous acid:

- Chloroform (CHCl ) has three chlorine atoms attached to a central carbon, which makes the C-H bond in chloroform weak and more likely to be dissociated. When chloroform loses a proton (H ), it forms a trichloromethyl anion (CCl ). This hydrogen is acidic due to the inductive effect of the chlorine atoms. Chlorine is highly electronegative and pulls electron density away from the C-H bond, making the hydrogen more positive and easily removable. This is why chloroform exhibits acidic properties.

(i) sec-butyl chloride:
- Structural formula:
- IUPAC name: Butyl chloride (2-chlorobutane). This is the sec-butyl group, where the chlorine atom is attached to the second carbon of the butane chain.
(ii) isopentyl bromide:
- Structural formula:
- IUPAC name: Pentyl bromide (3-bromobutane). This is the isopentyl group, where the bromine atom is attached to the third carbon of the pentane chain.
(iii) tert-butyl chloride:
- Structural formula:
- IUPAC name: Butyl chloride (2-chloro-2-methylpropane). This is the tert-butyl group, where the chlorine atom is attached to the central carbon in the isopropyl group.
(iv) isobutyl chloride:
- Structural formula:
- IUPAC name: Butyl chloride (1-chlorobutane). This is the isobutyl group, where the chlorine atom is attached to the first carbon of the butane chain.
(v) neopentyl chloride:
- Structural formula:
- IUPAC name: Pentyl chloride (1-chloro-2-methylpropane). This is the neopentyl group, where the chlorine atom is attached to the first carbon of the chain.

(i) Propanal and Propanone:
- Propanal (C H O): Propanal is an aldehyde with the structure CH CH CHO. The carbonyl group ( ) is at the end of the carbon chain, making it an aldehyde. In this structure: - The carbonyl group is attached to a hydrogen atom and a CH -CH group. - The functional group in aldehydes is always a terminal carbonyl group, meaning the group is always attached to a carbon atom at the end of the molecule. - Propanone (C H O): Propanone is a ketone with the structure CH COCH . The carbonyl group is attached to two methyl groups (CH ), making it a ketone. - The carbonyl group is in the middle of the carbon chain, unlike in aldehydes. - In ketones, the carbonyl group is attached to two other carbon atoms, which makes it a characteristic feature of ketones. Key Difference: The key difference between propanal and propanone lies in the position of the carbonyl group: - In propanal, the carbonyl group is at the end of the molecule (making it an aldehyde). - In propanone, the carbonyl group is in the middle of the molecule (making it a ketone). (ii) Phenol and Benzoic acid:
- Phenol (C H OH): Phenol is an aromatic compound with a hydroxyl group ( ) attached to a benzene ring. - The functional group in phenol is the hydroxyl group, which is directly attached to the aromatic ring. - Phenol has mild antiseptic properties and is used in the production of resins and other chemicals. - Benzoic acid (C H COOH): Benzoic acid is also an aromatic compound, but it contains a carboxyl group ( ) attached to the benzene ring. - The carboxyl group consists of a hydroxyl group (-OH) attached to a carbonyl group ( ). - Benzoic acid is commonly used in the production of dyes, perfumes, and preservatives. Key Difference: The functional groups in these two compounds are different: - Phenol has a hydroxyl group ( ) attached to the benzene ring. - Benzoic acid has a carboxyl group ( ) attached to the benzene ring. - This difference in functional groups leads to different chemical and physical properties for phenol and benzoic acid.

(A) CH3\text{ - CH = CH(CH}3\text{)Br}:
This is 3-Bromo-2-methylpropene. (B) (CH}3\text{)_2C - C - CH2\text{(Br)}:
This is 1-Bromo-3-methylbutane. (C) (CH}3\text{)_2CBrCH2\text{CH}3:
This is 1-Bromo-2,3-dimethylpropane. (D) (CH}3\text{)_3CCl:
This is tert-Butyl chloride. v) NO2\text{OH}\text{Cl on the benzene ring}:
This is 3-Nitro-4-hydroxyphenyl chloride. Final Answer: (A) 3-Bromo-2-methylpropene
(B) 1-Bromo-3-methylbutane
(C) 1-Bromo-2,3-dimethylpropane
(D) tert-Butyl chloride
v) 3-Nitro-4-hydroxyphenyl chloride

(i) Propanal and Propanone:
- Propanal (C H O): Propanal is an aldehyde with the structure CH CH CHO. The carbonyl group ( ) is at the end of the carbon chain, making it an aldehyde. In this structure: - The carbonyl group is attached to a hydrogen atom and a CH -CH group. - The functional group in aldehydes is always a terminal carbonyl group, meaning the group is always attached to a carbon atom at the end of the molecule. - Propanone (C H O): Propanone is a ketone with the structure CH COCH . The carbonyl group is attached to two methyl groups (CH ), making it a ketone. - The carbonyl group is in the middle of the carbon chain, unlike in aldehydes. - In ketones, the carbonyl group is attached to two other carbon atoms, which makes it a characteristic feature of ketones. Key Difference: The key difference between propanal and propanone lies in the position of the carbonyl group: - In propanal, the carbonyl group is at the end of the molecule (making it an aldehyde). - In propanone, the carbonyl group is in the middle of the molecule (making it a ketone). (ii) Phenol and Benzoic acid:
- Phenol (C H OH): Phenol is an aromatic compound with a hydroxyl group ( ) attached to a benzene ring. - The functional group in phenol is the hydroxyl group, which is directly attached to the aromatic ring. - Phenol has mild antiseptic properties and is used in the production of resins and other chemicals. - Benzoic acid (C H COOH): Benzoic acid is also an aromatic compound, but it contains a carboxyl group ( ) attached to the benzene ring. - The carboxyl group consists of a hydroxyl group (-OH) attached to a carbonyl group ( ). - Benzoic acid is commonly used in the production of dyes, perfumes, and preservatives. Key Difference: The functional groups in these two compounds are different: - Phenol has a hydroxyl group ( ) attached to the benzene ring. - Benzoic acid has a carboxyl group ( ) attached to the benzene ring. - This difference in functional groups leads to different chemical and physical properties for phenol and benzoic acid.

(i) Kolbe Reaction:
The Kolbe reaction involves the electrolysis of sodium or potassium salts of carboxylic acids, resulting in the decarboxylation and coupling of alkyl radicals to form alkanes.
Example:
Electrolysis of sodium acetate gives ethane: (ii) Reimer–Tiemann Reaction:
The Reimer–Tiemann reaction introduces a formyl group ( ) into the aromatic ring of phenols, mainly at the ortho position, using chloroform ( ) and alkali (NaOH/KOH).
Example:
Phenol reacts with chloroform in alkaline medium to give salicylaldehyde (2-hydroxybenzaldehyde). (iii) Williamson Ether Synthesis:
The Williamson ether synthesis involves the reaction of a sodium alkoxide with a primary alkyl halide to form ethers. It is a nucleophilic substitution ( ) reaction.
Example:
Sodium ethoxide reacts with methyl iodide to give ethyl methyl ether:

Step 1: Functional group tests.
2,4-DNP test (A) contains a carbonyl group (aldehyde/ketone).
Tollens/Fehling tests not an aldehyde (A) is a ketone.
Iodoform test with I /NaOH methyl ketone fragment .
Step 2: Unsaturation test.
No decolourisation of Br -water/alkaline KMnO no reactive in the side chain (an aromatic ring does not respond to these).
Step 3: Use formulas to infer the skeleton.
Given molecular formula C H O with a methyl-ketone group suggests (acetophenone, phenyl methyl ketone).
Step 4: Check with oxidation product.
Strong oxidation of an aryl side chain (including aryl methyl ketones) with chromic acid gives benzoic acid, C H O , which matches (B).
(Consistency check: iodoform reaction of (A): )