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Updated: Jun 2, 2026
11:01
Preparation and In Vivo Use of an Activity-based Probe for N-acylethanolamine Acid Amidase
Published on: November 23, 2016
N-{4-[(E)-(4-Methyl-phen-yl)imino-meth-yl]phen-yl}acetamide
Acta Crystallographica. Section E, Structure Reports Online
|April 28, 2011
Summary
Two distinct molecules in the crystal structure of C(16)H(16)N(2)O exhibit different conformations. Intramolecular hydrogen bonds form ring motifs, while intermolecular hydrogen bonds create polymeric chains.
Area of Science:
- Crystallography
- Chemical Physics
- Materials Science
Background:
- Understanding molecular conformation and crystal packing is crucial for predicting material properties.
- Polymorphism and conformational isomerism can significantly influence a compound's physical and chemical behavior.
- Hydrogen bonding plays a key role in directing crystal assembly and stabilizing specific molecular arrangements.
Purpose of the Study:
- To elucidate the crystal structure and conformational characteristics of the title compound, C(16)H(16)N(2)O.
- To investigate the role of intramolecular and intermolecular interactions in the self-assembly of the molecules in the solid state.
- To analyze the specific hydrogen bonding motifs and their contribution to the overall crystal architecture.
Main Methods:
- Single-crystal X-ray diffraction was employed to determine the three-dimensional structure of the compound.
- Analysis of crystallographic data included the measurement of dihedral angles and identification of hydrogen bonding interactions.
- The study involved the characterization of molecular conformation and the analysis of crystal packing motifs.
Main Results:
- Two symmetry-independent molecules with differing conformations were identified in the asymmetric unit.
- Dihedral angles between benzene rings were measured as 44.35(19)° and 48.14(17)°, with opposite twisting directions.
- Intramolecular C-H⋯O interactions formed S(6) ring motifs, and strong N-H⋯O hydrogen bonds resulted in C(4) chain motifs, leading to two independent polymeric structures.
Conclusions:
- The crystal structure of C(16)H(16)N(2)O reveals significant conformational diversity within the asymmetric unit.
- Intramolecular hydrogen bonding contributes to the formation of specific ring structures within each molecule.
- Intermolecular hydrogen bonding dictates the assembly into extended polymeric chains, highlighting the importance of non-covalent interactions in crystal engineering.
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01:11Nomenclature of Carboxylic Acid Derivatives: Amides and Nitriles
Naming Amides
The IUPAC and common names of amides are derived from the parent carboxylic acid, by replacing the suffix “oic acid” and “ic acid,” respectively, with “amide.” In the following example, the IUPAC name ethanamide is derived from ethanoic acid, and the common name, acetamide, is obtained from acetic acid.
The IUPAC and common names of amides are derived from the parent carboxylic acid, by replacing the suffix “oic acid” and “ic acid,” respectively, with “amide.” In the following example, the IUPAC name ethanamide is derived from ethanoic acid, and the common name, acetamide, is obtained from acetic acid.
01:17Nomenclature of Primary Amines
Primary, secondary, and tertiary amines are compounds consisting of one, two, and three alkyl groups connected to the amino group (–NH2), respectively. As depicted in Figure 1, the common name of the primary amines is obtained by adding the suffix -amine to the alkyl substituent attached to the amino group as the corresponding alkylamine.
01:19Amines to Amides: Acylation of Amines
Various carboxylic acid derivatives (such as acid chlorides, esters, and anhydrides) can be used for the acylation of amines to yield amides. The reaction requires two equivalents of amines. The first amine molecule functions as a nucleophile and attacks the carbonyl carbon to produce a tetrahedral intermediate. This is followed by the loss of the leaving group and restoration of the C=O bond.
Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary amide...
Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary amide...
01:07Acid Halides to Amides: Aminolysis
Aminolysis is a nucleophilic acyl substitution reaction, where ammonia or amines act as nucleophiles to give the substitution product. Acid halides react with ammonia, primary amines, and secondary amines to yield primary, secondary, and tertiary amides, respectively.
In the first step of the aminolysis mechanism, the amine attacks the carbonyl carbon of the acyl chloride to form a tetrahedral intermediate. In the second step, the carbonyl group is re-formed with the elimination of a chloride...
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01:33Carboxylic Acids to Methylesters: Alkylation using Diazomethane
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