Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Overview

1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO₂ Overview

Nitrous acid and nitric acids are two types of acids containing nitrogen, among which nitrous acid is weaker than nitric acid. Nitrous acid with a pKa value of 3.37 ionizes in water to give a nitrite ion and the hydronium ion.
The nitrous acid is unstable. Hence, it is formed in situ from a solution of sodium nitrite and cold aqueous acids such as hydrochloric or sulfuric acid. In an acidic solution, the –OH group of nitrous acid undergoes protonation to give oxonium ion, followed by water loss...

1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Mechanism

1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO₂ Mechanism

Nitrous acid is a relatively weak and unstable acid prepared in situ by the reaction of sodium nitrite and cold, dilute hydrochloric acid. In an acidic solution, the nitrous acid undergoes protonation when it loses water to form a nitrosonium ion—an electrophile. Nitrous acid reacts with primary amines to give diazonium salts. The reaction is called diazotization of primary amines.

2° Amines to N-Nitrosamines: Reaction with NaNO2

2° Amines to N-Nitrosamines: Reaction with NaNO₂

Secondary amines react with nitrous acid to form N-nitrosamines, as depicted in Figure 1. Nitrous acid, a weak and unstable acid, is formed in situ from an aqueous solution of sodium nitrite and strong acids, such as hydrochloric acid or sulfuric acid, in cold conditions. In the presence of an acid, the nitrous acid gets protonated. The subsequent loss of water results in the formation of the electrophile known as nitrosonium ion.

Nitrosation of Enols

Nitrosation of Enols

The nitrosation reaction is one of the methods of preparing 1,2-diketones. The enol tautomer of the starting ketone reacts with sodium nitrite in hydrochloric acid, generating the 1,2-diketone after hydrolysis.

Diazonium Group Substitution: –OH and –H

Diazonium Group Substitution: –OH and –H

Nitrous acid, a weak acid, is prepared in situ via the reaction of sodium nitrite with a strong acid under cold conditions. This nitrous acid prepared in situ reacts with primary arylamines to form arenediazonium salts. Such reactions are known as diazotization reactions. As shown in Figure 1, the formation of arenediazonium salts begins with the decomposition of nitrous acid in an acidic solution to give nitrosonium ions.

Aryldiazonium Salts to Azo Dyes: Diazo Coupling

Aryldiazonium Salts to Azo Dyes: Diazo Coupling

The reaction of weakly electrophilic aryldiazonium (also called arenediazonium) salts with highly activated aromatic compounds leads to the formation of products with an —N=N— link, called an azo linkage. This reaction, presented in Figure 1, is known as diazo coupling and occurs without the loss of the nitrogen atoms of the aryldiazonium salt. Highly activated aromatic compounds such as phenols or arylamines favor the diazo coupling reaction. The coupling generally occurs at the para position.

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Bis(ferrocenecarbaldehyde 4-methyl-thio-semicarbazonato-κN,S)zinc(II) methanol solvate.

Acta crystallographica. Section E, Structure reports online·2011

Same author

Poly[[diaqua-(3-carb-oxy-5-nitro-ben-zo-ato)(μ-5-nitro-benzene-1,3-dicarboxyl-ato)neodymium(III)] 2.5-hydrate].

Acta crystallographica. Section E, Structure reports online·2011

Same author

2-((E)-{2-[(E)-2,3-Dihydroxy-benzyl-ideneamino]-5-methyl-phen-yl}iminiometh-yl)-6-hydroxy-phenolate.

Acta crystallographica. Section E, Structure reports online·2011

Same author

Ethyl 4-butyl-amino-3-nitro-benzoate.

Acta crystallographica. Section E, Structure reports online·2011

Same author

(1Z)-1-(2,4-Dichloro-phen-yl)ethan-1-one semicarbazone.

Acta crystallographica. Section E, Structure reports online·2011

Same author

4-[(4-Fluoro-benzyl-idene)amino]-3-[1-(4-isobutyl-phen-yl)eth-yl]-1H-1,2,4-triazole-5(4H)-thione.

Acta crystallographica. Section E, Structure reports online·2011

Search research articles

Related Experiment Video

Updated: Jun 1, 2026

Green Synthesis of Quinoline-Based Ionic Liquid

Green Synthesis of Quinoline-Based Ionic Liquid

Published on: September 27, 2024

2-Cyano-quinolin-1-ium nitrate.

Wan-Sin Loh¹, Madhukar Hemamalini, Hoong-Kun Fun

¹X-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia.

Acta Crystallographica. Section E, Structure Reports Online

|May 19, 2011

Summary

This summary is machine-generated.

Crystallization of 2-cyano-quinoline with nitric acid forms a salt. This study details the salt

More Related Videos

Chemiluminescence-based Assays for Detection of Nitric Oxide and its Derivatives from Autoxidation and Nitrosated Compounds

Chemiluminescence-based Assays for Detection of Nitric Oxide and its Derivatives from Autoxidation and Nitrosated Compounds

Published on: February 16, 2022

Facile Preparation of 4-Substituted Quinazoline Derivatives

Facile Preparation of 4-Substituted Quinazoline Derivatives

Published on: February 15, 2016

Related Experiment Videos

Last Updated: Jun 1, 2026

Green Synthesis of Quinoline-Based Ionic Liquid

Green Synthesis of Quinoline-Based Ionic Liquid

Published on: September 27, 2024

Chemiluminescence-based Assays for Detection of Nitric Oxide and its Derivatives from Autoxidation and Nitrosated Compounds

Chemiluminescence-based Assays for Detection of Nitric Oxide and its Derivatives from Autoxidation and Nitrosated Compounds

Published on: February 16, 2022

Facile Preparation of 4-Substituted Quinazoline Derivatives

Facile Preparation of 4-Substituted Quinazoline Derivatives

Published on: February 15, 2016

Area of Science:

Crystallography
Supramolecular Chemistry
Organic Chemistry

Background:

2-cyano-quinoline is a heterocyclic organic compound.
Nitric acid is a strong mineral acid.

Purpose of the Study:

To characterize the salt formed between 2-cyano-quinoline and nitric acid.
To investigate the crystal structure and intermolecular interactions.

Main Methods:

Single-crystal X-ray diffraction analysis.
Crystallization techniques.

Main Results:

Formation of the 2-cyano-quinolinium nitrate salt (C(10)H(7)N(2) (+)·NO(3) (-)).
The quinolinium ring system exhibits near planarity.
A highly asymmetric bifurcated N-H⋯(O,O) hydrogen bond forms an R(2) (1)(4) ring motif.
C-H⋯O hydrogen bonds facilitate the formation of layered sheets.

Conclusions:

Proton transfer from nitric acid to 2-cyano-quinoline drives salt formation.
Detailed structural analysis reveals specific hydrogen bonding patterns.
The crystal packing is governed by electrostatic interactions and hydrogen bonding.