Primary, secondary, and tertiary amines are organic compounds that contain nitrogen atoms bonded to carbon atoms. They differ in the number of carbon atoms directly bonded to the nitrogen atom.1. Primary amines 1 amines : In primary amines, the nitrogen atom is bonded to one carbon atom and two hydrogen atoms. The general formula is RNH2, where R is an alkyl or aryl group. For example, methylamine CH3NH2 is a primary amine.2. Secondary amines 2 amines : In secondary amines, the nitrogen atom is bonded to two carbon atoms and one hydrogen atom. The general formula is R2NH, where R can be the same or different alkyl or aryl groups. For example, dimethylamine CH3 2NH is a secondary amine.3. Tertiary amines 3 amines : In tertiary amines, the nitrogen atom is bonded to three carbon atoms. The general formula is R3N, where R can be the same or different alkyl or aryl groups. For example, trimethylamine CH3 3N is a tertiary amine.Physical and chemical properties:Primary and secondary amines can form hydrogen bonds with water, making them more soluble in water than tertiary amines. Tertiary amines cannot form hydrogen bonds due to the absence of hydrogen atoms bonded to the nitrogen atom. As a result, tertiary amines have lower boiling points than primary and secondary amines.In terms of basicity, amines act as Lewis bases, donating a lone pair of electrons to form a bond with a Lewis acid. Generally, the basicity of amines decreases in the order: primary > secondary > tertiary. This trend is due to the inductive effect of alkyl groups, which can donate electron density to the nitrogen atom, making it less available for bonding with a Lewis acid.Methods of preparation for amines and amides:1. Reduction of nitro compounds: Nitro compounds can be reduced to primary amines using reducing agents like hydrogen gas with a metal catalyst e.g., palladium on carbon or using iron and hydrochloric acid. For example, nitrobenzene can be reduced to aniline C6H5NH2 .2. Ammonolysis of alkyl halides: Alkyl halides can react with ammonia to form primary amines. However, this reaction can also produce secondary and tertiary amines as side products. For example, ethyl chloride CH3CH2Cl can react with ammonia to form ethylamine CH3CH2NH2 .3. Gabriel synthesis: This method involves the reaction of phthalimide with an alkyl halide, followed by hydrolysis to produce primary amines. For example, phthalimide can react with ethyl bromide to form N-ethylphthalimide, which can then be hydrolyzed to form ethylamine.4. Hofmann rearrangement: This reaction involves the conversion of primary amides to primary amines with one fewer carbon atom. The amide is treated with chlorine or bromine and a strong base, leading to a rearrangement and loss of a carbon atom. For example, benzamide C6H5CONH2 can be converted to aniline C6H5NH2 using this method.Methods of preparation for amides:1. Reaction of carboxylic acids with amines: Carboxylic acids can react with amines to form amides, with water as a byproduct. For example, acetic acid CH3COOH can react with ammonia NH3 to form acetamide CH3CONH2 .2. Reaction of acid chlorides with amines: Acid chlorides can react with amines to form amides, with hydrogen chloride as a byproduct. For example, acetyl chloride CH3COCl can react with ammonia NH3 to form acetamide CH3CONH2 .3. Reaction of esters with amines: Esters can react with amines in the presence of an acid catalyst to form amides, with alcohol as a byproduct. This reaction is called aminolysis. For example, ethyl acetate CH3COOCH2CH3 can react with ammonia NH3 to form acetamide CH3CONH2 .