Question

Provide a structure for each of the following: (a) isoquinoline (b) quinoline N-oxide (c) 1,4 -dihydropyridine (d) N-benzylphthalimide (e) ethy1 5 -diphenylamino-2-pentenoate

Short answer

(a) Isoquinoline:  (b) Quinoline N-oxide:  (c) 1,4-Dihydropyridine:  (d) N-benzylphthalimide:  (e) Ethyl 5-diphenylamino-2-pentenoate: 

Step-by-step solution

(a) Isoquinoline)

To draw the structure of isoquinoline, we can follow these steps: 1. Start with a benzene ring 2. Add a nitrogen atom connected to one of the carbon atoms in the ring 3. Add another carbon atom connected to the nitrogen atom 4. Close the ring by connecting the new carbon atom to another carbon atom in the benzene ring Here is the structure for isoquinoline: 

(b) Quinoline N-oxide)

To draw the structure of quinoline N-oxide, we can follow these steps: 1. Start with the quinoline structure, a benzene ring fused with a pyridine ring. 2. Add an oxygen atom connected to the nitrogen atom in the pyridine ring. Here is the structure for quinoline N-oxide: 

(c) 1,4-Dihydropyridine)

To draw the structure of 1,4-dihydropyridine, we can follow these steps: 1. Start with a 6-membered ring containing one nitrogen atom and five carbon atoms 2. Add double bonds between positions 3 and 4, and between positions 5 and 6 in the ring 3. Add hydrogen atoms to the nitrogen and carbon atoms at positions 1 and 4 Here is the structure for 1,4-dihydropyridine: 

(d) N-benzylphthalimide)

To draw the structure of N-benzylphthalimide, we can follow these steps: 1. Start with the phthalimide structure, which contains two carbonyl groups connected to a central nitrogen atom in a cyclic structure 2. Add a benzyl group (phenylmethane) at the nitrogen atom in the phthalimide structure Here is the structure for N-benzylphthalimide: 

(e) Ethyl 5-diphenylamino-2-pentenoate)

To draw the structure of ethyl 5-diphenylamino-2-pentenoate, we can follow these steps: 1. Start with a pentene molecule, containing a double bond between carbon positions 2 and 3 2. Add an ethyl ester group (–COOEt) to carbon position 1 3. Add a diphenylamino (NPh2) group at carbon position 5 Here is the structure for ethyl 5-diphenylamino-2-pentenoate: 

Key concepts

Understanding the Isoquinoline Structure

Isoquinoline is an organic compound that consists of a benzene ring fused to a pyridine ring. The structure is similar to quinoline, but with the nitrogen atom located at the second position of the pyridine ring.

The structural formula of isoquinoline can be envisioned by first creating a six-membered benzene ring. To this ring, a nitrogen atom is attached at one end, followed by the addition of another carbon, forming a second six-membered ring fused with the first. It's important to recognize that in the isoquinoline skeleton, the nitrogen atom plays a pivotal role in the compound's chemical reactivity and properties.

Due to its heterocyclic aromatic nature, isoquinoline is involved in many chemical biological processes and is present in various naturally occurring alkaloids. It's commonly used in the synthesis of pharmaceuticals and dyes.

Quinoline N-oxide Structure Demystified

Quinoline N-oxide is a derivative of quinoline where an oxygen atom is bonded to the nitrogen atom of the pyridine ring through a process known as oxidation.

To picture the structure, start with the basic scaffold of quinoline - a benzene ring fused to a pyridine ring. Next, an oxygen atom is introduced, bound to the nitrogen atom in the pyridine ring, forming an N-oxide group. This alteration leads to significant changes in the compound's electronic distribution and chemical behavior, making the N-oxide structure more polar and adding a layer of complexity to its reactions.

Quinoline N-oxide is worthy of study due to its applications in organic synthesis and as intermediates in the preparation of other complex quinoline derivatives.

1,4-Dihydropyridine Structure Overview

The 1,4-dihydropyridine structure is recognized for its presence in various pharmacologically active compounds. Its ring system comprises one nitrogen atom and five carbon atoms, which forms the basic pyridine structure; however, it's partially saturated.

In constructing the 1,4-dihydropyridine structure, envision a six-membered ring with a nitrogen at one position. Unlike pyridine, this structure has single bonds at positions 1 and 4, relative to the nitrogen, hence the prefix 'dihydro.' The double bonds are then located between positions 3 and 4, and 5 and 6, granting the molecule a partial degree of unsaturation.

This structural feature is pivotal for the molecule's chemical properties and is the cornerstone for the therapeutic class of calcium channel blockers. Adding substituents to this ring can lead to medicines that treat cardiovascular diseases.

N-benzylphthalimide Structure Explained

N-benzylphthalimide features a phthalimide core, which is a cyclic imide derivative of phthalic acid, where two carbonyl groups are bonded to the same nitrogen atom.

When visualizing N-benzylphthalimide, one should start with the phthalimide skeleton and then introduce a benzyl group attached to the nitrogen atom. This benzyl moiety consists of a benzene ring connected to a methylene (-CH2-) group, and its presence significantly alters the phthalimide's reactivity and solubility.

Molecules like N-benzylphthalimide are vital in synthetic organic chemistry, used as intermediates in a variety of synthesis reactions, especially in the production of pharmaceuticals and agrochemicals.

The Ethyl 5-diphenylamino-2-pentenoate Structure

Ethyl 5-diphenylamino-2-pentenoate is a compound structured around a five-carbon alkene chain, known as pentene. This structure is modified by an ethyl ester group at one end and a diphenylamino group at the other.

Imagine starting with a linear chain of five carbons with a double bond between the second and third carbons. Then, at the terminal carbon, an ethyl ester (-COOEt) group is attached, rendering it an ester of pentenoic acid. At the opposite end, the diphenylamino (NPh2) group is bonded to the fifth carbon, which involves a nitrogen atom attached to two phenyl rings. This modification significantly affects the compound's electronic properties and reactivity.

Such structures are often seen in dyes and pigments and have applications in organic photonics and electronic materials due to their particular optical properties.