Synthesis
2-PHENYL-1,3-THIAZOLE-4-CARBOXYLIC ACID was synthesized from benzaldehyde via a one-pot reaction with methyl 3-(dimethylamino)-2-isocyanoacrylate. This method features mild reaction conditions, high purity, simple operation, and no catalyst required, and can assemble various functional groups into the molecule.

Synthetic reaction formula of 2-phenyl-1,3-thiazolyl-4-carboxylic acid
Experimental procedure:
Synthesis of methyl 2-phenyl-1,3-thiazolyl-4-carboxylate
Benzaldehyde, methyl 3-(dimethylamino)-2-isocyanoacrylate, and anhydrous methanol were added sequentially to a reaction flask. Anhydrous magnesium sulfate was added with stirring, and the mixture was cooled in an ice-water bath and reacted at 0℃ for 2 h. The temperature was then raised to 30℃ and reacted for 16 h. The solvent was evaporated under vacuum to obtain methyl 2-phenyl-1,3-thiazolyl-4-carboxylate.
Synthesis of 2-PHENYL-1,3-THIAZOLE-4-CARBOXYLIC ACID: Methyl 2-phenyl-1,3-thiazol-4-carboxylate, aqueous lithium hydroxide solution, and methanol were added sequentially to a reaction flask, and the mixture was reacted at 30°C for 6 h with stirring. The solvent was removed under vacuum, the pH was adjusted to 3-5 with dilute hydrochloric acid, and the mixture was extracted with dichloromethane (2 × 50 mL). The extracts were combined, concentrated, and purified by silica gel column chromatography [eluent: V(dichloromethane):V(methanol) = 15:1] to obtain 2-PHENYL-1,3-THIAZOLE-4-CARBOXYLIC ACID.;