tert-Butyl 2-chloro-1,3-thiazole-5-carboxylate 934570-60-2 98% white to off-white crystalline powder pharmaceutical intermediate

1. Product Overview

tert-Butyl 2-chloro-1,3-thiazole-5-carboxylate (CAS 934570-60-2) is a thiazole-based carboxylic ester featuring a chloro substituent at the 2-position and a tert-butyl carboxylate group at the 5-position of the 1,3-thiazole ring. Also referred to as 2-chloro-1,3-thiazole-5-carboxylic acid tert-butyl ester, it serves as a versatile building block in medicinal chemistry and heterocyclic synthesis, where the electron-deficient thiazole core combined with orthogonal reactivity (labile 2-Cl for nucleophilic aromatic substitution or cross-coupling; stable tert-butyl ester for deprotection to the acid) makes it valuable for constructing thiazole-containing active pharmaceutical ingredients (APIs), kinase inhibitors, and agrochemical intermediates. The compound typically appears as a white to off-white crystalline powder with good stability under dry, refrigerated conditions.

2. Key Features and Advantages

• Orthogonal reactivity: 2-chloro is displaceable by amines/thiols or participates in Pd-catalyzed couplings; tert-butyl ester survives many reaction conditions and is cleanly removed with TFA or mild acid to give the 5-carboxylic acid.

• Thiazole scaffold is a privileged heterocycle in drug discovery (kinase inhibitors, antimicrobials, antifungals) and agrochemicals, enabling rapid SAR exploration via 2- and 5-position diversification.

• High purity grade (≥98%) ensures reproducible multi-step synthesis with minimal halogen/ester-related impurities.

• Stable crystalline solid form facilitates accurate weighing, handling, and QC by melting point, HPLC, NMR, and LC-MS.

• Compatible with standard protecting-group strategies: thiazole N-alkylation avoided; ester deprotection selective over aryl chloride under controlled conditions.

3. Main Applications

• Pharmaceutical intermediate for thiazole-based drug candidates, especially kinase inhibitors, anti-infectives, and CNS programs where 2,5-disubstituted thiazoles are key pharmacophores.

• Building block for 2-amino/substituted-1,3-thiazole-5-carboxylates via SNAr with amines or Pd-catalyzed animations/Suzuki at C2, followed by ester deprotection and amide coupling.

• Intermediate in CRO/CDMO custom synthesis and academic research for thiazole library generation, heterocyclic method development (Chan–Lam coupling at C2, ester hydrolysis/reduction), and peptidomimetic design.

• Used as a precursor to 2-chloro-1,3-thiazole-5-carboxylic acid (via TFA deprotection) and further to amides, esters, and reduced alcohols relevant to agrochemical fungicide/insecticide programs.

• Employed in fragment-based drug design to introduce a thiazole-5-carboxylate handle for linking aromatic/aliphatic fragments via amide or urea formation after deprotection.

4. Technical Specifications

5. Storage and Handling

Store in a cool, dry place at 2–8 °C in a tightly sealed, light-protected container under desiccated conditions. For long-term storage, keep at –20 °C in a dry inert atmosphere to prevent moisture uptake and slow hydrolysis of the tert-butyl ester. The 2-chloro-thiazole is moderately reactive toward strong nucleophiles; avoid contact with amines, thiols, or strong bases at elevated temperatures which may displace chloride prematurely. Handle in a well-ventilated area with standard PPE (lab coat, nitrile gloves, safety glasses). Reseal promptly after use. Under recommended conditions, shelf life is typically 24 months; periodic HPLC check advised if stored above 8 °C or exposed to humidity.

6. Safety Overview

Intended for research and synthetic use only; not for direct human or veterinary therapeutic administration. May cause irritation to eyes, skin, and respiratory tract upon contact or dust inhalation (typical GHS07 profile: H315/H319/H335). Chlorinated thiazoles and esters can be mildly irritating to mucous membranes; handle as a fine organic powder with standard laboratory precautions. Prevent dust generation. In case of skin contact, wash thoroughly with soap and water; for eye contact, rinse cautiously with plenty of water for several minutes and seek medical advice if irritation persists. Dispose according to local regulations for halogenated heterocyclic organic laboratory chemicals. Always consult the latest SDS from the supplier before use.