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Preparation and In Vivo Use of an Activity-based Probe for N-acylethanolamine Acid Amidase
Published on: November 23, 2016
Bis[N-benzyl-2-(quinolin-8-yl-oxy)acetamide] monohydrate
Acta Crystallographica. Section E, Structure Reports Online
|August 13, 2011
Summary
This study details the crystal structure of a novel acetamide compound, revealing specific dihedral angles and hydrogen bonding interactions that stabilize its molecular arrangement in the solid state.
Area of Science:
- Crystallography
- Organic Chemistry
- Supramolecular Chemistry
Background:
- Understanding the three-dimensional structure of organic molecules is crucial for predicting their properties and reactivity.
- Acetamide derivatives are important in various chemical and pharmaceutical applications.
- Crystal packing forces significantly influence the physical and chemical characteristics of solid-state compounds.
Purpose of the Study:
- To elucidate the crystal structure of the title compound, 2C(18)H(16)N(2)O(2)·H(2)O.
- To analyze the dihedral angles between the quinoline and benzene rings within the acetamide molecules.
- To investigate the intermolecular interactions, specifically hydrogen bonding, governing the crystal packing.
Main Methods:
- Single-crystal X-ray diffraction was employed to determine the molecular and crystal structure.
- Analysis of bond lengths, bond angles, and dihedral angles was performed.
- Intermolecular interactions, including hydrogen bonds, were identified and characterized.
Main Results:
- The crystal structure of 2C(18)H(16)N(2)O(2)·H(2)O was successfully determined.
- Two independent acetamide molecules exhibit distinct dihedral angles between their quinoline and benzene rings: 80.09(5)° and 61.23(5)°.
- The crystal lattice is stabilized by a network of O-H⋯N and N-H⋯O hydrogen bonds involving acetamide and water molecules.
Conclusions:
- The study provides precise structural data for the title acetamide compound.
- The observed dihedral angles highlight conformational variations in the independent molecules.
- Hydrogen bonding plays a key role in the supramolecular assembly and stability of the crystal structure.
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Nomenclature of Aromatic Compounds with a Single Substituent
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Nomenclature 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.
Electrophilic Aromatic Substitution: Nitration of Benzene
The nitration of benzene is an example of an electrophilic aromatic substitution reaction. It involves the formation of a very powerful electrophile, the nitronium ion, which is linear in shape. The reaction occurs through the interaction of two strong acids, sulfuric and nitric acid.
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.
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The hybridized nitrogen atom in amines possesses a lone pair of electrons and is bound to three substituents with a bond angle of around 108°, which is less than the tetrahedral angle of 109.5°. However, the C–N–H bond angle is slightly larger at 112°, with a carbon–nitrogen bond length of 147 pm. This carbon–nitrogen bond length of of amines is longer than the carbon–oxygen bond of alcohols (143 pm) but shorter than alkanes’ carbon–carbon bond (154 pm). These aspects are illustrated in Figure...
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The secondary and tertiary amines are derivatives of ammonia, where two and three of its hydrogens are replaced by alkyl groups, respectively. Secondary and tertiary amines can be symmetrical with identical alkyl groups attached to the nitrogen atom or unsymmetrical when more than one type of alkyl group is present. The standard nomenclature of secondary and tertiary amines is similar to the names given to the primary amines. They are generally named alkylamines. As depicted in Figure 1, for...

