Related Experiment Video
Updated: May 31, 2026
11:51
Facile Preparation of 4-Substituted Quinazoline Derivatives
Published on: February 15, 2016
2-Methyl-4-phenyl-3,4-dihydro-quinazoline
Summary
Researchers synthesized a novel quinazoline derivative, C(15)H(14)N(2), via lithiation and hydrolysis. Structural analysis confirmed its conformation in solution and solid state, revealing significant phenyl ring twisting and intermolecular hydrogen bonding in crystals.
Area of Science:
- Organic Chemistry
- Crystallography
- Spectroscopy
Background:
- Quinazoline derivatives are important heterocyclic compounds with diverse biological activities.
- Understanding the structure-activity relationship requires detailed characterization of novel derivatives.
- Lithiation reactions offer a versatile route for functionalizing heterocyclic systems.
Purpose of the Study:
- To synthesize and characterize a novel 2-methyl-4-phenyl-4H-quinazolin-3-ide derivative.
- To elucidate the three-dimensional structure of the synthesized compound in both solution and solid state.
- To investigate the intermolecular interactions within the crystalline structure.
Main Methods:
- Organometallic reaction: Lithiation of 2-methyl-quinazoline using phenyl-lithium.
- Hydrolysis: Treatment of the intermediate lithium salt to yield the final product.
- Nuclear Magnetic Resonance (NMR) spectroscopy: To determine the structure in solution.
- Single-crystal X-ray diffraction: To determine the precise molecular and crystal structure.
Main Results:
- Successful synthesis of the title compound, C(15)H(14)N(2).
- NMR and X-ray data confirmed identical structures in chloroform solution and crystalline state.
- The phenyl substituent exhibited significant twisting (86.47°) out of the quinazoline ring plane.
- Infinite chains were formed in the crystal via intermolecular N-H⋯N hydrogen bonds.
Conclusions:
- The study successfully synthesized and characterized a novel quinazoline derivative.
- The compound maintains its unique twisted conformation in both solution and solid states.
- Intermolecular N-H⋯N interactions play a crucial role in the crystal packing of this compound.
![Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F60786.jpg&w=3840&q=50)
Related Concept Videos
01:17Oxidation of Phenols to Quinones
In the presence of oxidizing agents, phenols are oxidized to quinones. Quinones can be easily reduced back to phenols using mild reducing agents. The electron-donating hydroxyl group enhances the reactivity of the aromatic ring, enabling oxidation of the ring even in the absence of an α hydrogen.
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox property is crucial in...
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox property is crucial in...
02:23Structure and Nomenclature of Alcohols and Phenols
Overview
Alcohols are one of the most important functional groups in organic chemistry. The name of alcohol comes from the hydrocarbon from which it is derived. Alcohols are organic molecules containing the functional hydroxyl or –OH group directly bonded to carbon. Phenols have an OH group directly attached to a benzene ring. While alcohols are colorless, phenol is a white crystalline compound with a characteristic "hospital smell" odor.
As with other organic compounds, alcohols and phenols...
Alcohols are one of the most important functional groups in organic chemistry. The name of alcohol comes from the hydrocarbon from which it is derived. Alcohols are organic molecules containing the functional hydroxyl or –OH group directly bonded to carbon. Phenols have an OH group directly attached to a benzene ring. While alcohols are colorless, phenol is a white crystalline compound with a characteristic "hospital smell" odor.
As with other organic compounds, alcohols and phenols...
01:10Radical Chain-Growth Polymerization: Overview
Chain-growth or addition polymerization is successive addition reactions of monomers with a polymer chain. In radical chain-growth polymerization, the reaction proceeds via a free-radical intermediate. The free radical is formed from radical initiators, which spontaneously generate free radicals by homolytic fission. Organic peroxides (such as dibenzoyl peroxide, as shown in Figure 1) or azo compounds are popular radical initiators. A low concentration ratio of radical initiator to monomer is...
01:11Aryldiazonium Salts to Azo Dyes: Diazo Coupling
The reaction of weakly electrophilic aryldiazonium (also called arenediazonium) salts with highly activated aromatic compounds leads to the formation of products with an —N=N— link, called an azo linkage. This reaction, presented in Figure 1, is known as diazo coupling and occurs without the loss of the nitrogen atoms of the aryldiazonium salt. Highly activated aromatic compounds such as phenols or arylamines favor the diazo coupling reaction. The coupling generally occurs at the para position.
01:11Nomenclature 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...
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...
01:27Benzene to Phenol via Cumene: Hock Process
The synthesis of phenol from benzene via cumene and cumene hydroperoxide is called the Hock process. First, a Friedel–Crafts alkylation reaction of benzene with propene gives cumene. Then cumene forms cumene hydroperoxide via a radical chain reaction. In the chain initiation step, the benzylic hydrogen is abstracted to give a benzylic radical. In the chain propagation step, the benzylic radical reacts with an oxygen diradical to form a cumene hydroperoxide radical. The cumene hydroperoxide...