Related Experiment Video

Updated: May 21, 2026

Determination of 45 Pesticides in Avocado Varieties by the QuEChERS Method and Gas Chromatography-Tandem Mass Spectrometry
05:20

Determination of 45 Pesticides in Avocado Varieties by the QuEChERS Method and Gas Chromatography-Tandem Mass Spectrometry

Published on: December 8, 2023

N-[2,4-Dioxo-3-aza-tricyclo-[7.3.1.0(5,13)]trideca-1(13),5,7,9,11-pentaen-3-yl]thio-urea

Rashad Al-Salahi, Mohamed Al-Omar, Mohamed Marzouk

    Acta Crystallographica. Section E, Structure Reports Online
    |June 22, 2012
    PubMed

    More Related Videos

    Modification and Functionalization of the Guanidine Group by Tailor-made Precursors09:45

    Modification and Functionalization of the Guanidine Group by Tailor-made Precursors

    Published on: April 27, 2017

    Analysis of Organochlorine Pesticides in a Soil Sample by a Modified QuEChERS Approach Using Ammonium Formate04:17

    Analysis of Organochlorine Pesticides in a Soil Sample by a Modified QuEChERS Approach Using Ammonium Formate

    Published on: January 20, 2023

    Related Concept Videos

    Nomenclature of Aryl and Heterocyclic Amines01:10

    Nomenclature of Aryl and Heterocyclic Amines

    The simplest aromatic amine is phenylamine, which contains an –NH2 functionality directly attached to an aromatic ring. The name aniline is designated for this skeleton. As shown in Figure 1, the common names of the functionalized anilines involve prefixes ortho-, meta-, and para- to indicate the substitution position. Different functionalized aniline derivatives also have notable trivial names.
    Diazonium Group Substitution: –OH and –H01:19

    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.
    1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Overview01:26

    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...
    Aryldiazonium Salts to Azo Dyes: Diazo Coupling01:11

    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.
    1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Mechanism01:37

    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.
    Carboxylic Acids to Methylesters: Alkylation using Diazomethane01:33

    Carboxylic Acids to Methylesters: Alkylation using Diazomethane

    Carboxylic acids react with diazomethane in an ether solvent via alkylation at the carboxylate oxygen atom to give methyl esters of the corresponding acid with excellent yields.