Question

Draw a structural formula for each amine and amine derivative. (a) \(N, N\)-Dimethylaniline (b) Triethylamine (c) tert-Butylamine (d) 1,4 -Benzenediamine (e) 4-Aminobutanoic acid (f) \((R)\)-2-Butanamine (g) Benzylamine (h) trans-2-Aminocyclohexanol (i) 1-Phenyl-2-propanamine (amphetamine) (j) Lithium diisopropylamide (LDA) (k) Benzyltrimethylammonium hydroxide (Triton B)

Short answer

Question: Draw the structural formulas for the following amines and amine derivatives: a) N,N-Dimethylaniline b) Triethylamine c) tert-Butylamine d) 1,4-Benzenediamine e) 4-Aminobutanoic acid f) (R)-2-Butanamine g) Benzylamine h) trans-2-Aminocyclohexanol i) 1-Phenyl-2-propanamine (amphetamine) j) Lithium diisopropylamide (LDA) k) Benzyltrimethylammonium hydroxide (Triton B)

Step-by-step solution

(a) N,N-Dimethylaniline

To draw the structural formula of N,N-Dimethylaniline, first identify the aniline (C6H5NH2) as the base structure and two methyl groups (CH3) attached to the nitrogen atom. The resulting compound is C6H5N(CH3)2.

(b) Triethylamine

To draw the structural formula of Triethylamine, start by identifying the central nitrogen atom and connect three ethyl groups (CH2CH3) to it. The resulting compound is N(CH2CH3)3.

(c) tert-Butylamine

To draw the tert-Butylamine structure, first draw the central nitrogen atom, and connect one hydrogen atom and one tert-butyl group (C(CH3)3) to it. The resulting compound is HN(C(CH3)3).

(d) 1,4-Benzenediamine

To draw the structural formula of 1,4-Benzenediamine, start with the benzene ring (C6H6), and attach two amine groups (NH2) at positions 1 and 4 of the ring. The resulting compound is C6H4(NH2)2.

(e) 4-Aminobutanoic acid

To draw the structural formula of 4-Aminobutanoic acid, start with a straight carbon chain with 4 carbons, a carboxylic acid group (COOH) at one end, and an amine group (NH2) at the other end. The resulting compound is NH2(CH2)3COOH.

(f) \((R)-2\)-Butanamine

To draw the structural formula of \((R)-2\)-Butanamine, start with a straight carbon chain with 4 carbons, and an amine group (NH2) on the second carbon. Take into account the \((R)\) stereochemistry at the chiral center. The resulting compound is CH3CH(NH2)CH2CH3.

(g) Benzylamine

To draw the structural formula of Benzylamine, start with the benzene ring (C6H5) and attach an amine group (NH2) to the carbon adjacent to the ring. The resulting compound is C6H5CH2NH2.

(h) trans-2-Aminocyclohexanol

To draw the structural formula of trans-2-Aminocyclohexanol, start with a cyclohexane ring, and attach an amine group (NH2) and a hydroxyl group (OH) on the second carbon. Pay attention to the trans stereochemistry. The resulting compound is NH2CH(OH)C5H9.

(i) 1-Phenyl-2-propanamine (amphetamine)

To draw the structural formula of 1-Phenyl-2-propanamine (amphetamine), start with a straight carbon chain with 3 carbons, an amine group (NH2) on the second carbon, and a phenyl group (C6H5) attached to the first carbon. The resulting compound is C6H5CH(CH2NH2)CH3.

(j) Lithium diisopropylamide (LDA)

To draw the structural formula of Lithium diisopropylamide (LDA), start with a central lithium atom (Li) and attach two isopropyl groups [(CH3)2CH] and one amide group (N) to it. The resulting compound is LiN((CH3)2CH)2.

(k) Benzyltrimethylammonium hydroxide (Triton B)

To draw the structural formula of Benzyltrimethylammonium hydroxide (Triton B), start with the central nitrogen atom and attach three methyl groups (CH3), one benzyl group (C6H5CH2), and one hydroxide group (OH) to it. The resulting compound is OHC6H5CH2N(CH3)3.

Key concepts

Amine Derivatives

Amine derivatives are organic compounds that contain an amine group, which consists of a nitrogen atom bonded to one or more alkyl or aromatic substituents. These derivatives are made by replacing one or more hydrogen atoms of ammonia (NH3) with organic groups.

Examples of amine derivatives include anilines (where the amine group is attached to an aromatic ring) and amides (where the amine group is bonded to a carbonyl group, CO). These derivatives are important in a wide range of chemical reactions and are found in various applications such as in pharmaceuticals, dyes, and polymers. A deep understanding of how to draw and interpret their structure is crucial for students of organic chemistry. For instance, in 'N,N-Dimethylaniline,' the presence of two methyl groups attached to the nitrogen atom makes it a secondary amine, affecting its reactivity and physical properties.

Drawing Organic Compounds

Understand Skeletal Structures

The skeletal structure is a method of drawing organic molecules in which carbon atoms are implied at the corners of lines and termini of lines unless otherwise indicated. This method simplifies drawing and understanding of large molecules. It's essential to recognize the key structural features such as chains, branches, and rings.

Recognize Functional Groups

Functional groups are specific atoms, or groups of atoms, within molecules that are responsible for the characteristic chemical reactions of those molecules. The amine group, for example, is a common functional group that can alter the reactivity of the compound it is part of.

Learning how to draw organic compounds requires practice in recognizing structural patterns and proficiency in the use of symbolism in chemical representation. Simplifying complex molecules into more manageable diagrams helps with the quick understanding of their properties and reactivity patterns.

Amines in Organic Chemistry

Amines in organic chemistry are very versatile and functionally rich compounds that consist of a nitrogen atom bonded to one or more alkyl or aryl groups. They're classified based on the number of carbon-containing groups attached to the nitrogen: primary amines have one, secondary have two, and tertiary amines have three such groups.

Amines occur naturally in plants and animals and are also synthesized for industrial purposes. They can behave as bases, nucleophiles, or in some cases, even as ligands in coordination chemistry. The presence of the amine group can affect boiling points, solubility, and the molecular geometry of the compounds they are part of. Understanding the foundational principles of amines and their derivatives is an invaluable skill for students pursuing studies in organic chemistry.