Related Experiment Video
Updated: Jun 5, 2026
11:01
Preparation and In Vivo Use of an Activity-based Probe for N-acylethanolamine Acid Amidase
Published on: November 23, 2016
(E)-Benzo-yl[1-(2-hydroxy-ethyl)imidazolidin-2-yl-idene]acetonitrile
Acta Crystallographica. Section E, Structure Reports Online
|January 5, 2011
Summary
The study reveals that specific hydrogen bonds cause the imidazolidine ring and a C=C(H)-C=O group to align in the title compound. These interactions also influence how molecules pack together in the crystal structure.
Area of Science:
- Organic Chemistry
- Crystallography
- Molecular Interactions
Background:
- Understanding molecular conformation and crystal packing is crucial in organic chemistry.
- Hydrogen bonding plays a significant role in determining the solid-state structure of organic compounds.
Purpose of the Study:
- To investigate the structural features of the title compound C(14)H(15)N(3)O(2).
- To elucidate the role of intra- and inter-molecular hydrogen bonds in dictating molecular planarity and crystal packing.
Main Methods:
- Single-crystal X-ray diffraction analysis was employed to determine the molecular and crystal structure.
- Analysis of hydrogen bonding networks (N-H⋯O and O-H⋯N) and electronic conjugation was performed.
Main Results:
- The C=C(H)-C=O grouping and the imidazolidine ring were found to be coplanar.
- An intra-molecular N-H⋯O hydrogen bond and extended electronic conjugation were identified as key factors for planarity.
- Inter-molecular N-H⋯O and O-H⋯N hydrogen bonds were observed to govern the crystal packing.
Conclusions:
- The observed planarity of the title compound is a direct consequence of intramolecular hydrogen bonding and electronic conjugation.
- The crystal structure is stabilized by a network of intermolecular hydrogen bonds, highlighting their importance in molecular assembly.
Related Concept Videos
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.
01:07Alkylation of β-Ketoester Enolates: Acetoacetic Ester Synthesis
Acetoacetic ester synthesis is a method to obtain ketones from alkyl halides and β-keto esters. The reaction occurs in the presence of an alkoxide base that abstracts the acidic proton of the β-keto esters. The step results in an enolate ion which is doubly stabilized. The enolate then reacts with an alkyl halide via the SN2 process to produce an alkylated ester intermediate with a new C–C bond. The hydrolysis of the intermediate, followed by acidification, results in an alkylated β-keto acid.
01:28Structures of Carboxylic Acid Derivatives
Structure of Carboxylic Acid Derivatives
Carboxylic acid derivatives contain an acyl group attached to a heteroatom such as chlorine, oxygen, or nitrogen. The carbonyl carbon and oxygen are both sp2-hybridized with an unhybridized p orbital.
The three sp2 orbitals of the carbonyl carbon form three σ bonds, one each with the carbonyl oxygen, the α carbon, and the heteroatom, whereas the other two sp2 orbitals of the carbonyl oxygen are occupied by the lone pairs. Further, the unhybridized p...
Carboxylic acid derivatives contain an acyl group attached to a heteroatom such as chlorine, oxygen, or nitrogen. The carbonyl carbon and oxygen are both sp2-hybridized with an unhybridized p orbital.
The three sp2 orbitals of the carbonyl carbon form three σ bonds, one each with the carbonyl oxygen, the α carbon, and the heteroatom, whereas the other two sp2 orbitals of the carbonyl oxygen are occupied by the lone pairs. Further, the unhybridized p...
02:42Acidity of 1-Alkynes
The acidic strength of hydrocarbons follows the order: Alkynes > Alkenes > Alkanes. The strength of an acid is commonly expressed in units of pKa — the lower the pKa, the stronger the acid. Among the hydrocarbons, terminal alkynes have lower pKa values and are, therefore, more acidic. For example, the pKa values for ethane, ethene, and acetylene are 51, 44, and 25, respectively, as shown here.
01:19Types of Enols and Enolates
Aldehydes and ketones form enols, although only about 1% of the enol is present at the equilibrium for simple monocarbonyl compounds. The enol form is undetectable for acetaldehyde, present as only 1.5 × 10−4 % of acetone, and present as only 1.2% of cyclohexanone. Two kinds of regioisomeric enols are possible for unsymmetrical ketones, and their net composition is 1% at equilibrium. This instability is due to the lower bond energy of C=C than the C=O group. The additional instability of enols...
01:14Alkylation of β-Diester Enolates: Malonic Ester Synthesis
Malonic ester synthesis is a method to obtain α substituted carboxylic acids from ꞵ-diesters such as diethyl malonate and alkyl halides.