(S)-2-(5-fluoro-6-hydroxybenzo[d]thiazol-2-yl)-4,5-dihydrothiazole-4-carboxylic acid
[CAS# 916661-57-9]

Identification

• Classification: Organic raw materials >> Carboxylic compounds and derivatives
• Name: (S)-2-(5-fluoro-6-hydroxybenzo[d]thiazol-2-yl)-4,5-dihydrothiazole-4-carboxylic acid
• Synonyms: (4S)-2-(5-fluoro-6-hydroxy-1,3-benzothiazol-2-yl)-4,5-dihydro-1,3-thiazole-4-carboxylic acid
• Molecular Formula: C₁₁H₇FN₂O₃S₂
• Molecular Weight: 298.31
• CAS Registry Number: 916661-57-9
• SMILES: C1[C@@H](N=C(S1)C2=NC3=CC(=C(C=C3S2)O)F)C(=O)O

Properties

• Density: 1.9±0.1 g/cm³ Calc.^*
• Boiling point: 570.0±60.0 °C 760 mmHg (Calc.)^*
• Flash point: 298.5±32.9 °C (Calc.)^*
• Index of refraction: 1.84 (Calc.)^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H302-H315-H319
• Safety Statements: P501-P270-P264-P280-P302+P352-P337+P313-P305+P351+P338-P362+P364-P332+P313-P301+P312+P330

Discovery and Applications

(S)-2-(5-fluoro-6-hydroxybenzo[d]thiazol-2-yl)-4,5-dihydrothiazole-4-carboxylic acid is a heterocyclic organic compound belonging to the class of substituted benzothiazole thiazoline carboxylic acids. It is a structural analogue of firefly luciferin, the natural substrate for luciferase enzymes that produce bioluminescence, but distinguished by a fluorine atom at the 5-position of the benzothiazole ring and a hydroxyl group at the 6-position. The molecule contains a fused heterocyclic benzothiazole core linked to a partially saturated thiazoline ring bearing a carboxylic acid functional group and has defined stereochemistry at the carbon bearing the acid group, designated as the (S) enantiomer.

This class of compounds is primarily studied for its role in bioluminescence. Luciferin derivatives, including this fluorinated analogue, act as substrates for luciferase-catalyzed reactions that produce visible light in the presence of adenosine triphosphate (ATP) and oxygen. The stereochemistry of the thiazoline ring is critical for enzyme recognition and efficient light emission, and the natural (S) configuration is preserved in synthetic analogues.

The fluorinated benzothiazole derivative allows researchers to investigate how chemical modifications affect bioluminescence properties such as emission wavelength, stability, and substrate specificity. Fluorine substitution can influence the photophysical behavior of the molecule when oxidized by luciferase, potentially shifting emission spectra or improving imaging characteristics in biological systems.

Synthetically, benzothiazole-thiazoline carboxylic acids are prepared by cyclization of benzothiazole precursors with amino acids such as cysteine, which introduces the thiazoline ring and carboxylic acid group. Fluorinated analogues are synthesized by using a fluorinated benzothiazole derivative. The (S) stereochemistry is controlled through the use of the corresponding enantiomer of cysteine during cyclization. These synthetic strategies are standard for generating luciferin analogues and related heterocyclic carboxylic acids for biochemical studies.

The compound is widely used in molecular and cellular biology for bioluminescence imaging. Luciferin derivatives paired with luciferase enzymes serve as highly sensitive reporters for monitoring gene expression, cell viability, and biochemical processes in live cells, tissues, and whole organisms. Modifications of luciferin, such as fluorination, allow tuning of emission properties for enhanced imaging, such as shifting emission to longer wavelengths to increase tissue penetration or improve resolution.

Fluorinated analogues like (S)-2-(5-fluoro-6-hydroxybenzo[d]thiazol-2-yl)-4,5-dihydrothiazole-4-carboxylic acid are also of interest for studying enzyme kinetics, binding affinities, and the effects of substituents on bioluminescent output. Fluorine can enhance chemical stability and alter metabolic behavior, making these analogues valuable probes in biochemical assays and imaging studies. The compound is primarily used in research and is not employed as a therapeutic or industrial chemical outside specialized biochemical applications.

Overall, (S)-2-(5-fluoro-6-hydroxybenzo[d]thiazol-2-yl)-4,5-dihydrothiazole-4-carboxylic acid exemplifies a tailored heterocyclic substrate in the family of luciferin derivatives. Its structural features, including the fluorine substituent, hydroxyl group, and stereochemically defined thiazoline ring, enable studies of bioluminescence mechanisms, enzyme-substrate interactions, and imaging applications in biological systems.

References

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