Question

In the given reactions: $$ \text { Glucose }+\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{NH}-\mathrm{NH}_{2} \stackrel{\mathrm{H}^{\oplus} / \Delta}{\longrightarrow} \text { Osazone }+\mathrm{A}+\mathrm{B} $$ \((\mathrm{A})\) and \((\mathrm{B})\) are (A) \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{NH}_{2}\) and \(\mathrm{NH}_{3}\) (B) \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{NH}_{2}\) and \(\mathrm{NH}_{2} \mathrm{OH}\) (C) \(\mathrm{C}_{6} \mathrm{H}_{5}-\mathrm{NHOH}\) and \(\mathrm{NH}_{3}\) (D) \(\mathrm{NH}_{2} \mathrm{OH}\) and \(\mathrm{HOH}\)

Short answer

The correct answer is (A), with A being C6H5NH2 and B being NH3.

Step-by-step solution

Reaction Mechanism

The nitrogen in aniline (C6H5NH-NH2) is more reactive towards glucose due to resonance. Under the presence of acid (H+ ions), glucose forms a resonance-stabilized imine intermediate with aniline. Then, further reaction occurs, leading to osazone formation and the release of two molecules as byproducts.

Identify A and B in each option

We need to look at each option and evaluate if it can be formed through the reaction pathway mentioned in Step 1. (A) C6H5NH2 and NH3 (B) C6H5NH2 and NH2OH (C) C6H5-NHOH and NH3 (D) NH2OH and HOH

Evaluate plausible options using reaction mechanism

Based on Step 1, we know that glucose reacts with aniline to form a resonance-stabilized imine intermediate. Hence, the byproduct A should contain the remaining elements of the aniline molecule. (A) In this option, A and B are two plausible byproducts because C6H5NH2 has the remaining elements of aniline, and NH3 can be released during the reaction. (B) In this option, C6H5NH2 also has the remaining elements of aniline, but NH2OH is not a suitable byproduct since it is not formed from the elements involved in the reaction. (C) In this option, C6H5-NHOH can be a plausible byproduct, but NH3 cannot be since it was formed in the imine intermediate during the reaction. (D) NH2OH is not a suitable byproduct, as mentioned in option B. HOH is not formed during the reaction due to the absence of hydrogen on oxygen.

Determine the correct answer choice

By analyzing each option and the possible byproducts, we can conclude that option (A) is the correct choice. C6H5NH2 can be formed from the remaining elements of aniline, and NH3 can be a byproduct produced during the reaction. Therefore: A: C6H5NH2 B: NH3

Key concepts

Organic Chemistry

Organic Chemistry is a vast field that encompasses the study of carbon-containing compounds and their properties, reactions, and synthesis. A significant aspect of understanding this subject involves familiarizing oneself with various functional groups, reaction mechanisms, and chemical behavior of organic molecules. In the context of osazone formation, a key topic within Organic Chemistry is the interaction between carbohydrates, like glucose, and organic compounds such as phenylhydrazine (C6H5NH-NH2). This reaction illustrates the intricacy of Organic Chemistry, as it involves multiple steps leading to the formation of a complex product - the osazone. The osazone formation reaction not only highlights the importance of functional groups in determining the reactivity of a molecule but also shows how an initial reactant like glucose could be transformed through a sequence of steps involving the creation of intermediates and the eventual rearrangement into a new structure.

One of the main educational takeaways from osazone formation is the application of concepts such as resonance stabilization and nucleophilic attack, which are fundamental to many organic reactions. Recognition of the components involved in the reaction and the byproducts is essential. As students dive into the mechanism of osazone formation, they develop a deeper understanding of how complex structures are built from simpler organic molecules, which is a crucial skill not only for academic purposes but also for practical laboratory work.

Reaction Mechanism

A reaction mechanism provides a step-by-step detailed view of how a chemical reaction proceeds from reactants to products. Understanding a reaction mechanism is crucial for predicting the outcome of organic chemical reactions. In the exercise involving osazone formation from glucose and phenylhydrazine, the mechanism goes through multiple phases. Initially, glucose reacts with aniline derivatives to form a Schiff base. This imine then undergoes further transformations leading to the formation of the osazone. Crucial to the discussion of the reaction mechanism is the role of acid catalysis, which aids the formation of the imine intermediate by providing protons (H+ ions) for reaction acceleration.

Highlighting in the explanation, the mechanism clearly shows how the phenylhydrazine nitrogen acts as a nucleophile, attacking the electrophilic carbonyl carbon of glucose to form an intermediate. This sort of interaction is the cornerstone for understanding many other organic reactions where nucleophilic substitution plays a vital role. Educators and content creators should emphasize the importance of intermediates - they often hold the key to understanding both the course of a reaction and the nature of its byproducts. As the osazone forms, byproducts are also released, which is a common scenario in organic synthesis. Through exercises like these, students learn to visualize the detailed steps of reactions, an essential skill for their progression in advanced organic chemistry.

JEE Advanced Organic Chemistry

For students preparing for competitive exams like the JEE Advanced, which is a highly competitive entrance examination for engineering colleges in India, understanding complex organic chemistry topics is crucial. The osazone formation reaction is a perfect example of the type of concept that could be examined. It tests the understanding of organic reaction mechanisms, the ability to predict products, as well as the knowledge of functional groups and molecular structures.

In preparation for such exams, it is important for students to not only solve problems but also understand the underlying principles. For instance, in this reaction, recognizing that glucose can exist in an open-chain form that contains an aldehyde group that can react with phenylhydrazine is key. It's metabolic nuances like this that often differentiate a well-prepared student from the rest. Content tailored to JEE Advanced Organic Chemistry should clearly illustrate the pathway from reactants to products and include a discussion on why certain byproducts are formed and others are not. Students should be able to apply these skills to a range of organic reactions - a requirement for success in JEE Advanced and necessary for any future study in organic chemistry.