Related Experiment Video

Updated: May 18, 2026

Facile Preparation of 4-Substituted Quinazoline Derivatives
11:51

Facile Preparation of 4-Substituted Quinazoline Derivatives

Published on: February 15, 2016

4-Methyl-3-phenyl-2,4-dihydro-pyrazolo-[4,3-c][1,2]benzothia-zine 5,5-dioxide

Sana Aslam, Hamid Latif Siddiqui, Matloob Ahmad

    Acta Crystallographica. Section E, Structure Reports Online
    |September 13, 2012
    PubMed

    More Related Videos

    Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions07:12

    Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions

    Published on: July 17, 2020

    Preparation of N-(2-alkoxyvinyl)sulfonamides from N-tosyl-1,2,3-triazoles and Subsequent Conversion to Substituted Phthalans and Phenethylamines10:42

    Preparation of N-(2-alkoxyvinyl)sulfonamides from N-tosyl-1,2,3-triazoles and Subsequent Conversion to Substituted Phthalans and Phenethylamines

    Published on: January 3, 2018

    Related Concept Videos

    Five-Membered Heterocyclic Aromatic Compounds: Overview01:13

    Five-Membered Heterocyclic Aromatic Compounds: Overview

    Heterocyclic aromatic compounds are cyclic compounds that are aromatic and have one or more heteroatoms—atoms other than carbon, in the ring. Depending upon the number of atoms present in the ring, they can be either five or six-membered. Examples of five-membered heterocyclic aromatic compounds include pyrrole, furan, thiophene, and imidazole. Pyrrole consists of one nitrogen atom having one lone pair of electrons. Furan and thiophene have one oxygen and one sulfur heteroatom, respectively.
    Structure of Benzene: Molecular Orbital Model01:18

    Structure of Benzene: Molecular Orbital Model

    According to the molecular orbital (MO) model, benzene has a planar structure with a regular hexagon of six sp2 hybridized carbons. As shown in Figure 1, each carbon is bonded to three other atoms with C–C–C and H–C–C bond angles of 120°. The C–H bond length is 109 pm, and the C–C bond length is 139 pm which is midway between the single bond length of sp3 hybridized carbons (154 pm) and sp2 hybridized carbons (133 pm).
    Structure of Benzene: Kekulé Model01:07

    Structure of Benzene: Kekulé Model

    In 1865, August Kekule suggested the structure of benzene according to the structural theory of organic chemistry based on the three assertions—formula of benzene is C6H6, all the hydrogens of benzene are equivalent, and each carbon must have four bonds due to its tetravalency.
    He proposed that benzene has a cyclic structure of six carbon atoms attached to one hydrogen atom each, with three alternating pi bonds.
    NMR Spectroscopy of Benzene Derivatives01:37

    NMR Spectroscopy of Benzene Derivatives

    Simple unsubstituted benzene has six aromatic protons, all chemically equivalent. Therefore, benzene exhibits only a singlet peak at δ 7.3 ppm in the 1H NMR spectrum. The observed shift is far downfield because the aromatic ring current strongly deshields the protons. Any substitution on the benzene ring makes the aromatic protons nonequivalent, and the protons split each other. The peak is, therefore, no longer a singlet and the splitting pattern and their associated coupling constants depend...
    Hydrolysis of Chlorobenzene to Phenol: Dow Process01:10

    Hydrolysis of Chlorobenzene to Phenol: Dow Process

    Simple aryl halides do not react with nucleophiles under normal conditions. However, the reaction can proceed under drastic conditions involving high temperatures and high pressure to give the substituted products. For example, chlorobenzene is converted to phenol using aqueous sodium hydroxide at 350 °C under high pressure by the Dow process. The reaction follows an elimination-addition mechanism involving a benzyne intermediate. Here, the chloride ion is eliminated to generate the benzyne...
    Nomenclature of Aromatic Compounds with Multiple Substituents01:11

    Nomenclature of Aromatic Compounds with Multiple Substituents

    When more than one substituent is present on the benzene ring, the IUPAC nomenclature depends on the number of substituents present.
    For disubstituted benzene derivatives, with two groups attached to the benzene ring, three constitutional isomers are possible. For example, consider dimethyl benzene, often called xylene, where the second methyl group can be substituted at the second, third, or fourth carbon. The relative position of the substituents is represented by prefixes ortho, meta, or...