Thiazole-4-Carboxylic Acid represents an important organic compound, relied upon in various chemical synthesis routes and pharmaceutical research. Chemically, it's built from a thiazole ring holding a carboxylic acid group at the fourth position. The molecular formula takes the form C4H3NOS2, and it brings together sulfur and nitrogen in a stable heterocyclic design. CAS number 39098-97-0, HS Code 2934999099. A look at this structure shows a five-membered ring, one sulfur atom, one nitrogen atom, and a carboxyl function that influences its reactivity profile.
On the bench, thiazole-4-carboxylic acid looks like a solid, generally available as a pale or off-white crystalline powder. Some manufacturers offer it as small flakes or as fine pearls, favoring ease of weighing and mixing during lab work. This chemical presents a specific density around 1.5 g/cm³, depending on purity and hydration state. In the hand—assuming all safety precautions in place—it doesn’t feel oily or sticky, but holds together in an even, grainy texture. Melting range usually falls into 175-178°C, which alerts chemists to store it at room temperature, sealed dry from humidity that may cause caking. The substance dissolves slowly in water, more readily in polar organics like dimethyl sulfoxide or ethanol. During routine use, its carboxyl group lends hydrophilic character, but the thiazole ring stands out for its aromaticity and robustness.
Batch specifications often demand purity above 98%, with trace heavy metals and moisture content tightly controlled. Infrared and NMR spectroscopy help confirm batch quality; seasoned chemists trust these spectra to catch batch deviations. From my own time in applied synthesis, the material’s resilience stands out: it handles mild heating, stays inert against many bases, and only reacts strongly in presence of activating agents. This matters for pharmaceutical or specialty chemical manufacturers looking to build more complex molecules, since thiazole-4-carboxylic acid offers a site for amide coupling, esterification, or custom derivatization. Such versatility appears in records of antibiotics development, specialty dye production, and advanced material synthesis.
Direct contact, inhalation, or accidental ingestion pose risks typical for low-molecular-weight organic acids. While not explosively hazardous or highly flammable, the compound calls for gloves, goggles, and lab coat—minimizing skin or eye irritation. Long breathing exposure, while unlikely, could cause nose or throat discomfort, echoing the mild acidity of the solid. Material safety data sheets describe the hazard levels as moderate: not a major toxin, but still a chemical, no food contact or medical use without explicit qualification. Lab storage sticks to basics—low humidity, limited light, tight-capped bottles made from glass or HDPE. Waste goes into designated organic chemical bins, following local hazardous waste handling rules.
The use of thiazole-4-carboxylic acid stretches across several industries. Chemists incorporate it while assembling heterocyclic medicines, agrochemical intermediates, and even certain battery materials. Its core thiazole ring, along with the reactive acid tail, offers both rigidity and flexibility—allowing chemists to form new bonds without losing the ring’s stability. I’ve worked with this compound during the synthesis of drug candidates meant to interact with bacterial enzymes, and its purity directly impacts how cleanly those reactions flow. The balance of physical stability, solubility in lab solvents, and chemical reactivity adds up to a strong raw material, cutting down on reaction byproducts and simplifying purification.
Shipped and stored as crystalline solid, thiazole-4-carboxylic acid travels in sealed plastic bags or wide-mouth bottles inside cardboard shockproof boxes. The density of about 1.5 g/cm³ means that 1 liter holds roughly 1.5 kilograms—useful for scaling up reactions. Labs rarely find it in liquid form, but, in solution, the compound starts to show up as a weakly acidic, almost colorless liquid. My own experience has found that grinding it into a fine powder doesn’t generate much dust, lowering inhalation risk during weigh-out, but a good fume hood makes routine handling more secure. For cleaning, common organic solvents like methanol or acetonitrile dissolve any traces off spatulas and glassware.
Though not immediately harmful to the wider environment, thiazole-4-carboxylic acid waste deserves respect. Regulations classify it as an organic hazardous chemical, with safe disposal a non-negotiable. Environmental impact studies show that even low-toxicity organics can build up over time. In larger industrial settings, any solution wash or solid discard funnels into chemical waste management. Factories logging shipments record HS Code 2934999099 for customs; researchers must reference the substance’s REACH status or country-specific chemical inventories before import or export. Adherence to such restrictions upholds both human health and environmental standards.
Thiazole-4-carboxylic acid stands as a reliable, well-characterized intermediate, its properties shaped by a robust molecular structure and straightforward solid-state behavior. The compound fits lab and industrial workflows so long as users pay attention to handling, storage, and disposal—balancing its essential role with real respect for health and safety. As a raw material, it supports innovation, but only in skilled and conscientious hands. This chemical story is, at its core, as much about responsible stewardship as the science itself.
