Related Experiment Video

Updated: Jun 5, 2026

Synthesis of pH Dependent Pyrazole, Imidazole, and Isoindolone Dipyrrinone Fluorophores using a Claisen-Schmidt Condensation Approach
14:11

Synthesis of pH Dependent Pyrazole, Imidazole, and Isoindolone Dipyrrinone Fluorophores using a Claisen-Schmidt Condensation Approach

Published on: June 10, 2021

5-Fluoro-1-(3-metylbutano-yl)pyrimidine-2,4(1H,3H)-dione

Hans-Joachim Lehmler, Sean Parkin

    Acta Crystallographica. Section E, Structure Reports Online
    |January 5, 2011
    PubMed

    More Related Videos

    Microwave-Assisted Preparation of 1-Aryl-1H-pyrazole-5-amines05:07

    Microwave-Assisted Preparation of 1-Aryl-1H-pyrazole-5-amines

    Published on: June 23, 2019

    Regioselective O-Glycosylation of Nucleosides via the Temporary 2',3'-Diol Protection by a Boronic Ester for the Synthesis of Disaccharide Nucleosides08:46

    Regioselective O-Glycosylation of Nucleosides via the Temporary 2',3'-Diol Protection by a Boronic Ester for the Synthesis of Disaccharide Nucleosides

    Published on: July 26, 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.
    Electrophilic Aromatic Substitution: Fluorination and Iodination of Benzene01:13

    Electrophilic Aromatic Substitution: Fluorination and Iodination of Benzene

    Bromination and chlorination of aromatic rings by electrophilic aromatic substitution reactions are easily achieved, but fluorination and iodination are difficult to achieve. Fluorine is so reactive that its reaction with benzene is difficult to control, resulting in poor yields of monofluoroaromatic products. To address this, Selectfluor reagent is used as a fluorine source in which a fluorine atom is bonded to a positively charged nitrogen.
    π Molecular Orbitals of 1,3-Butadiene01:24

    π Molecular Orbitals of 1,3-Butadiene

    Conjugated dienes have lower heats of hydrogenation than cumulated and isolated dienes, making them more stable. The enhanced stabilization of conjugated systems can be understood from their π molecular orbitals.
    The simplest conjugated diene is 1,3-butadiene: a four-carbon system where each carbon is sp2-hybridized and has an unhybridized p orbital that contains an unpaired electron. According to molecular orbital theory, atomic orbitals combine to form molecular orbitals such that the number...
    Alkyl Halides02:45

    Alkyl Halides

    Structural Properties
    Alkyl halides are halogen-substituted alkanes wherein one or more hydrogen atoms of an alkane is replaced by a halogen atom such as fluorine, chlorine, bromine, or iodine. The carbon atom in an alkyl halide is bonded to the halogen atom, which is sp3-hybridized and exhibits a tetrahedral shape.
    Unlike alkyl halides, compounds in which a halogen atom is bonded to an sp2 -hybridized carbon atom of a carbon-carbon double bond (C=C) are called vinyl halides. Whereas aryl...
    ortho–para-Directing Activators: –CH3, –OH, –⁠NH2, –OCH301:11

    ortho–para-Directing Activators: –CH3, –OH, –⁠NH2, –OCH3

    All ortho–para directors, excluding halogens, are activating groups. These groups donate electrons to the ring, making the ring carbons electron-rich. Consequently, the reactivity of the aromatic ring towards electrophilic substitution increases. For instance, the nitration of anisole is about 10,000 times faster than the nitration of benzene. The electron-donating effect of the methoxy group in anisole activates the ortho and para positions on the ring and stabilizes the corresponding...
    Basicity of Heterocyclic Aromatic Amines01:25

    Basicity of Heterocyclic Aromatic Amines

    Heterocyclic amines, where the N atom is a part of an alicyclic system, are similar in basicity to alkylamines. Interestingly, the heterocyclic amine having a nitrogen atom as part of an aromatic ring has much less basicity than its corresponding alicyclic counterpart. For this reason, as presented in Figure 1, piperidine (pKb = 2.8) is significantly more basic than pyridine (pKb = 8.8).