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Facile Preparation of 4-Substituted Quinazoline Derivatives
Published on: February 15, 2016
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Novel Azo Compounds Derived from Thiazolidine-4-one: Synthesis, Metal Complexation, Coloristic Properties, and
Thi Ngoc Anh Vu1,2, Anh Van Nguyen3, Minh Chin Huynh4
1Laboratory of Advanced Materials Chemistry, Institute for Advanced Study in Technology, Ton Duc Thang University, Ho Chi Minh City 700000, Vietnam.
ACS Omega
|November 17, 2025
Summary
Five novel azo compounds were developed as permanent hair dyes. These dyes exhibit good colorfastness and moderate antimicrobial activity, with low acute toxicity, making them promising for cosmetic applications.
Area of Science:
- Organic Chemistry
- Materials Science
- Cosmetic Science
Background:
- Azo compounds are widely used as dyes.
- Novel azo compounds are needed for permanent hair dyeing applications.
- 2-cyanomethylene-4-thiazolidinone is a promising scaffold for dye development.
Purpose of the Study:
- To synthesize and characterize novel azo compounds containing a 2-cyanomethylene-4-thiazolidinone fragment.
- To evaluate the potential of these compounds as permanent hair dyes.
- To assess their physicochemical properties, dyeing performance, stability, and toxicity.
Main Methods:
- Synthesis and isolation of five novel azo compounds.
- Physicochemical characterization including pKa determination.
- Complexation studies with transition 3d metal cations.
- Hair dyeing tests on bleached natural hair.
- Colorfastness evaluation against washing and UV irradiation.
- Antimicrobial activity testing.
- In silico and in vivo toxicity assessments.
Main Results:
- Five novel azo compounds were successfully synthesized.
- Compounds exhibit weak monobasic acid properties with pKa values from 7.83 to 11.87.
- Formation of moderately stable ML2-type metal complexes observed.
- Successful hair dyeing achieved with good colorfastness (resistant to 6 washes and UV irradiation).
- Medium antimicrobial activity against Gram-negative microorganisms.
- Dyes classified in acute toxicity classes 4 and 5.
Conclusions:
- Novel azo compounds containing the 2-cyanomethylene-4-thiazolidinone moiety are suitable for permanent hair dye applications.
- The synthesized dyes demonstrate good stability and performance.
- The compounds exhibit a favorable safety profile for cosmetic use.
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