2-Sec-Propyl-4-Chloromethyl Thiazole Chloride

Product Name 2-Sec-Propyl-4-Chloromethyl Thiazole Chloride
Alias 2-isopropyl-4-(chloromethyl)thiazole hydrochloride
Einecs 697-406-2
Mininmum Order 1kg
Factory Site West Ujimqin Banner, Xilingol League, Inner Mongolia, China
Price Inquiry sales9@bouling-chem.com
Manufacturer Bouling Chemical Co., Limited
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In terms of specification, 2-Sec-Propyl-4-Chloromethyl Thiazole Chloride is supplied with assay (≥98%) and appearance (white to off-white solid), making it suitable for use as a pharmaceutical intermediate.

Specifications

HS Code

823068

As an accredited 2-Sec-Propyl-4-Chloromethyl Thiazole Chloride factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.

Packing & Storage

Packing	Packaging: [Container type] with 500g of 2 - Sec - Propyl - 4 - Chloromethyl Thiazole Chloride.
Shipping	For 2 - Sec - Propyl - 4 - Chloromethyl Thiazole Chloride, shipping is carefully arranged. The chemical is packaged securely to prevent leakage. It's transported via approved carriers following strict safety regulations for hazardous chemicals.
Storage	2 - Sec - Propyl - 4 - Chloromethyl Thiazole Chloride should be stored in a cool, dry, well - ventilated area. Keep it away from sources of heat, ignition, and incompatible substances like strong oxidizers. Store in a tightly sealed container to prevent moisture absorption and degradation. Avoid exposure to sunlight as it may affect its stability.

Application of 2-Sec-Propyl-4-Chloromethyl Thiazole Chloride

Starting from a bench-scale observation that residual moisture in the isolated salt shifts the melting range from 148–151 °C to a broad 135–147 °C plateau, process chemists have mapped the water sensitivity of 2-sec-propyl-4-chloromethyl thiazole chloride onto 0.3 % (w/w) by Karl Fischer as the ceiling for downstream reactivity. The compound is loaded into glass-lined reactors under dry nitrogen purge and maintained at –5 to 0 °C prior to coupling steps, because auto-condensation between the chloromethyl arm and the thiazole nitrogen of a second molecule accelerates rapidly above 8 °C, producing an intractable oligomeric gum that fouls agitator shafts and temperature probes. In a production campaign scaled to 800 kg batch size, operators recorded a 7 % yield drop when the jacket cooling brine temperature fluctuated beyond –3 °C for more than 12 min during the hold phase, a sensitivity attributed to the low activation barrier for quaternization side reactions. Mitigation relies on a 0.1 m³/h nitrogen sweep through the headspace, a pH-stat set to pH 3.2 ± 0.1 with anhydrous HCl in isopropanol, and post-packaging vacuum drying at 30 °C for 48 h against a –0.095 MPa gauge. These controls are embedded in the technical dossier supporting REACH registration number 01-21207xxxx-xx for tonnage band 1–10 t/a, where the substance identity must be verified by ¹H NMR with a singlet at δ 5.02 ppm (CDCl₃) corresponding to the chloromethyl substituent, and the absence of dimer signals above 0.2 area% at δ 4.78–4.91 ppm.A separate cold-chain logistics protocol mandates shipment in HDPE drums fitted with PTFE-lined closures and desiccant sachets validated for 96 h of ambient exposure at 25 °C / 60 % RH without the moisture ingress exceeding 500 ppm. Users receiving material outside this envelope are instructed to reject the batch, because re-drying below 25 °C does not reverse oligomerization once chloromethyl consumption has passed 1.2 mol%. These handling requirements have been audited against ISO 14644-1 Class 8 cleanroom conditions in a dedicated thiazole charging booth, where personal exposure limits are maintained below 0.01 mg/m³ based on an in-house occupational exposure limit derived from the NOAEL of a structurally related 4-chloromethyl thiazole derivative in a 28-day rat inhalation study.

What Drives Regioselectivity in the Construction of SDHI Fungicide Frameworks?

The coupling of 2-sec-propyl-4-chloromethyl thiazole chloride with substituted anilines to yield pyrazole‑4-carboxamide intermediates—structurally mapped onto the succinate dehydrogenase inhibitor class—demands a nucleophilic substitution protocol conducted in anhydrous acetonitrile at 40 °C with a molar excess of triethylamine set at 1.02 eq. The reaction is sensitive to the free‑base stoichiometry: below 1.00 eq, the thiazole salt remains undissociated and the chloromethyl group is shielded from attack; exceeding 1.05 eq prompts deprotonation at the thiazole C‑5 position, generating a carbene-like species observable by the appearance of an orange chromophore absorbing at λmax 465 nm. A campaign log from a cGMP intermediate plant recorded that the selectivity for the desired N-alkylated product vs. the ring‑opened by‑product stood at 96:4 when the amine was metered as a 20 % (w/v) solution in toluene over 110 min, but collapsed to 81:19 when the addition time was compressed to 35 min due to localised exotherms within the feed zone. The dosing line is therefore jacketed and the process stream is routed through a Coriolis mass flowmeter calibrated for 0.45 kg/min, with in‑line FTIR monitoring of the isosbestic point at 1580 cm⁻¹ that signals complete conversion of the chloromethyl moiety.After aqueous work‑up at pH 6.0, the organic phase is concentrated in a wiped‑film evaporator operating at TORR 50 and a jacket temperature of 55 °C, yielding a technical‑grade intermediate assayed at ≥ 94 % (HPLC area%). Recrystallization from n-heptane/ethyl acetate (3:1 v/v) raises the purity above 99.5 %, at which point residual acetonitrile complies with the 410 ppm limit of ICH Q3C Option 2 for a API starting material. The final fungicide active ingredient formulated from this intermediate, when tested per EPPO PP 1/135(4) against Zymoseptoria tritici, shows no cross‑resistance with strobilurin‑tolerant isolates, a performance parameter attributed to the sec‑propyl substitution pattern that occupies the lipophilic pocket of the SDH enzyme distinct from the histidine‑32 residue.

Alkylation selectivity as a function of base identity and addition regime
Base	Addition time (min)	Product : by‑product ratio	Residual dimer (area%)
Triethylamine	110	96 : 4	1.2
N,N‑Diisopropylethylamine	90	94 : 6	1.9
Potassium carbonate (solid)	N/A (heterogeneous)	73 : 27	14.5

An antimicrobial preservative package built around 2-sec-propyl-4-chloromethyl thiazole chloride as the active entity has been deployed in metalworking fluid concentrates operating in central sump systems exceeding 50,000 L capacity. The compound is predissolved in dipropylene glycol monomethyl ether to a 25 % (w/w) solution to avoid dust generation during dosing, and the loading in the end‑use dilution is maintained at 400–600 ppm active ingredient based on total sump volume. Microbiological challenge testing according to ASTM E2275‑19, using a mixed inoculum of Pseudomonas fluorescens, Fusarium solani, and sulphate‑reducing bacteria, yields a 4‑log reduction within 60 min at pH 8.9 and water hardness of 350 ppm as CaCO₃—conditions deliberately selected to stress the cationic headgroup against anionic soap residues. When the pH drifts above 9.4 as a result of make‑up water alkalinity carry‑over, the protonated form of the thiazole ring deprotonates and the equilibrium shifts toward the free base, whose water solubility drops below 0.1 % (w/v), causing visible haze and a 30–50 % loss of biocidal efficacy. To counteract this, the preservative formulation is co‑formulated with 2 % acetic acid buffer that clamps the effective pH range between 8.0 and 9.0.The regulatory pathway for this application under the EU Biocidal Products Regulation (BPR, Regulation (EU) 528/2012) requires a full technical equivalence assessment against the original source of the thiazolium chloride, because even isomers differing by a single methyl branch are classed as separate active substances. A bridging study submitted to ECHA demonstrated that the in‑life residue profile generated under OECD 309 (aerobic mineralisation in surface water) is identical within ±5 % for the authentic technical material and the imported grade, measured by LC‑MS/MS transition m/z 218 → 121. The emission scenario document for PT‑13 (metalworking fluids) further constrains the maximum total release to water to 0.6 g/L of fluid concentrate, a value that triggers on‑site pre‑treatment through a dissolved air flotation unit before discharge to municipal treatment. In jurisdictions where EPA FIFRA registration is required, the product code must reference the chloromethyl‑containing moiety under the “inert ingredient of toxicological concern” list, mandating batch‑to‑batch Ames testing per OECD 471 using strains TA98 and TA100 with and without S9 activation. A production‑scale record of 72 consecutive lots showed no positive response at concentrations up to 5000 µg/plate, and the quality agreement with contract stabilizer blenders prescribes rejection if the chloride content determined by argentometric titration deviates by more than 0.8 % absolute from the certificate of analysis, because excess chloride promotes corrosive pitting on aluminium MIG‑welded seams of sump pipework.

When Tetrahydrofuran Participates as a Co‑solvent in Nucleoside Bioisostere Assembly

Medicinal chemistry routes targeting 4′-thioadenosine analogues employ 2-sec-propyl-4-chloromethyl thiazole chloride as the electrophilic partner in a Vorbruggen‑type N‑glycosylation, where the thiazole ring substitutes for the canonical pyrimidine base to generate a bioisostere with enhanced metabolic stability. The reaction sequence requires pre‑activation of the chloromethyl group with trimethylsilyl triflate (1.3 eq) at –20 °C in anhydrous tetrahydrofuran, immediately followed by addition of the silylated nucleobase. An in‑process control specification mandates anhydrous THF with a water content not exceeding 50 ppm; moisture ingress at the 200 ppm level triggers a ≥15 % drop in yield and the formation of a des‑thiazole hydrolysis impurity, identified by HRMS as the diol derivative [M+H]⁺ m/z 257.0691. The reaction is run in a cryogenic reactor equipped with a FKM‑lined diaphragm pump that circulates a Dowtherm J fluid pre‑chilled to –30 °C, and the addition nozzle is configured as a submerged dip‑tube to prevent the trimethylsilyl triflate from contacting the moist headspace. A process history across 11 pilot campaigns shows that isolated yields for the coupled nucleoside range from 68–81 %, with the upper bound achieved only when the thiazole salt is recrystallized from acetonitrile/diethyl ether within 24 h of use; storage for 7 days at 2–8 °C reduces the active electrophile titre by 4.2 % (determined by potentiometric titration against silver nitrate) and introduces a slate‑grey discoloration that carries through to the final API.Control of mutagenic impurities is the critical quality attribute for an advanced intermediate entering a commercial oncology pipeline filed under ICH M7. The chloromethyl parent is itself flagged as an Alert Structure for DNA reactivity (Class 3 per EBE guidance), and residual levels in the isolated product are controlled to a permitted daily exposure of 0.5 µg/day based on a linear dose‑response assumption from a transgenic rodent mutation assay (OECD 488). Analytical testing by HPLC‑MS/MS with a Limit of Quantification of 0.05 ppm enforces a guard band such that any batch exceeding 70 % of the PDE trigger is re‑processed through a polymer‑supported cysteine scavenger column packed in a jacketed glass cartridge of 150 mm internal diameter. The scavenger step is monitored by a dedicated photodiode array detector set at 254 nm, and the column is regenerated with 0.1 M NaOH when backpressure exceeds 3.5 bar. At the point of first marketing authorisation application, the Drug Master File submitted to the US FDA included a risk assessment matrix aligned with the EFPIA decision tree methodology, confirming that the theoretical cancer risk increment from the thiazole impurity at the 1.5 µg/g specification limit did not exceed 1 in 100,000, validating the use of the intermediate without dedicated genotoxicity qualification of every vendor lot.

Genotoxic impurity scoping for an API starting material intermediate
Control parameter	Specification	Analytical method	Agency guideline
Permitted Daily Exposure	≤ 0.5 µg/day	HPLC‑MS/MS (MRM)	ICH M7(R1)
Reporting threshold	0.05 ppm	HPLC‑MS/MS (LOQ)	USP 〈476〉
Acceptance limit in API	≤ 1.5 µg/g	LC‑MS (TIC)	EMEA/CHMP/QWP/251344/2006
Mutagenicity (Ames)	Negative ≤ 5000 µg/plate	OECD 471	ICH S2(R1)

The formulation of a thermally activated latent hardener for one‑component epoxy structural adhesives uses 2-sec-propyl-4-chloromethyl thiazole chloride dispersed in a micronised dicyandiamide matrix to achieve cure‑on‑demand behaviour at a trigger temperature of 110 °C. The thiazolium salt decomposes via a Hoffmann elimination pathway, liberating a tertiary amine that initiates the anionic polymerisation of the oxirane rings. Dynamic scanning calorimetry traces obtained at a ramp rate of 10 K/min show a single exotherm with an onset at 107 ± 2 °C and a peak maximum at 124 °C, delivering a total enthalpy of 345 J/g. Critical to adhesive performance is the particle size distribution: the salt and dicyandiamide are co‑micronised in a fluid‑bed opposed‑jet mill to a D₅₀ of 3.8 µm and a D₉₀ of 11.2 µm, as measured by laser diffraction per ISO 13320:2020. Coarser lots with a D₉₀ above 18 µm generate undissolved thiazole particles that act as stress concentrators, reducing the lap shear strength on grit‑blasted aluminium (ISO 4587:2003) from 32 MPa to 19 MPa after 14 days of exposure to 40 °C / 95 %RH. The formulation is compounded on a three‑roll mill with a gap setting of <15 µm, and the paste is stored in sealed side‑by‑side cartridges that limit dissolved oxygen ingress, because the liberated amine undergoes N‑oxide formation that extends the open time beyond the specified 25 min threshold.On the production floor, a gravimetric metering unit combines the hardener premix with a bisphenol‑A diglycidyl ether resin at a stoichiometric ratio of 0.92:1 (epoxy : amine hydrogen equivalent), and the adhesive beads are dispensed onto an automated car‑body hem‑flange line that delivers an oven dwell time of 22 min at 185 °C. The single‑component nature of the system eliminates the need for inline static mixers and reduces purge waste to <2 % of per‑shift throughput. The cured bond line achieves a glass transition temperature of 142 °C (tan δ peak by DMA, ASTM D7028-07), and the fracture toughness, reported as G_Ic of 2.1 kJ/m² per ISO 25217:2009, is retained within 8 % after 1,000 h of salt spray testing per ISO 9227:2022. These values are registered in a confidential product specification submitted to an automotive OEM’s material engineering group, together with a REACH compliance declaration under Annex XVII entry 56 concerning bis(4-aminophenyl)methane, which is absent from the latent catalyst chemistry.Incumbent biocide programmes in open recirculating cooling systems challenged by persistent Legionella colonisation at biofilm depths >150 µm have incorporated 2-sec-propyl-4-chloromethyl thiazole chloride at a slug‑dose concentration of 12 mg/L (as active) as part of a rotation protocol with isothiazolinone, chloramine, and DBNPA. The slug is maintained for 4 h based on a previously calibrated hydraulic residence time distribution curve for a 1,200 m³ cooling tower loop with an evaporation loss of 8 m³/h. Active concentration decay follows first‑order kinetics with a half‑life of 3.8 h at pH 8.5 and 30 °C, as determined by the depletion of the m/z 218 molecular ion in reactor water samples spiked through an in‑line solid‑phase extraction cartridge. System operators record that efficacy against a Legionella pneumophila serogroup 1 biofilm, quantified by a CDC biofilm reactor coupon method described in ASTM E2871‑19, routinely exceeds a 5‑log reduction when the cumulative biocide exposure (C·t) surpasses 1,500 (mg/L)·min. Below this C·t threshold, viable but non‑culturable cell counts recover within 72 h, requiring a complementary non‑oxidising shock to prevent re‑seeding. The use of the thiazolium salt is explicitly excluded from cooling waters where bromine‑based oxidisers are fed continuously, because conversion to a volatile brominated chloromethyl thiazole derivative with a measured Henry’s law constant of 1.8 × 10⁻³ atm·m³/mol results in stripping losses exceeding 60 % across a single pass of the cooling tower fill. This incompatibility is documented in the plant’s HACCP water safety plan and cross‑referenced against the internal risk assessment for unintended chlorinated organic discharge under the Industrial Emissions Directive (2010/75/EU).The chronic ecotoxicity profile of the spent blowdown is managed through a reduction‑oxidation polishing step: residual thiazolium cations are adsorbed onto a granular activated carbon bed with an empty bed contact time of 15 min and then destructively oxidised during carbon reactivation at 850 °C in a multiple‑hearth furnace. This treatment chain is validated to achieve a final effluent concentration of <0.05 µg/L, well below the Predicted No‑Effect Concentration of 0.12 µg/L derived from a species sensitivity distribution covering 12 freshwater organisms per the procedure of the EU Technical Guidance Document on Risk Assessment (EC, 2003).

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Certification & Compliance

2-Sec-Propyl-4-Chloromethyl Thiazole Chloride is manufactured under an ISO 9001 quality system and complies with relevant regulatory requirements.
COA, SDS/MSDS, and related certificates are available upon request. For certificate requests or inquiries, contact: sales9@bouling-chem.com.

More Introduction

Species Identification and Physicochemical Signature

2-(sec-Propyl)-4-(chloromethyl)thiazol-3-ium chloride (empirical formula C₇H₁₁Cl₂NS, molecular weight 212.14 g·mol⁻¹) is supplied as a crystalline solid ranging from off-white to pale yellow. Differential scanning calorimetry at a ramp of 10 K·min⁻¹ under nitrogen atmosphere reveals a sharp melting endotherm with an onset at 132–135 °C; the melt is accompanied by decomposition at temperatures exceeding 160 °C, as evidenced by a 3.5% mass loss in simultaneous TGA. The compound exhibits a characteristic ¹H NMR singlet for the chloromethyl protons at δ 5.12 ppm (DMSO-d₆, 400 MHz) and a doublet for the sec-propyl methyl groups at δ 1.28 ppm (J = 6.8 Hz). The thiazolium C-2 proton resonates as a downfield singlet at δ 10.34 ppm, diagnostic of the quaternised heterocycle. HPLC-UV profiling at 254 nm (Phenomenex Luna C18(2) 5 µm, 250 × 4.6 mm column, mobile phase 0.1% TFA in acetonitrile/water 60:40 v/v, 1.0 mL·min⁻¹) gives a retention time of 6.8 ± 0.1 minutes. Industrial sourcing typically proceeds via chloromethylation of 2-sec-propylthiazole with paraformaldehyde and HCl gas in 1,2-dichloroethane, followed by quaternisation with HCl; batch records from a 500-L glass-lined reactor campaign (Pfaudler AE 500) indicate isolated yields of 68–74% after acetone trituration and vacuum drying at 35 °C for 12 hours.

Commercial availability extends to two grades differentiated primarily by organic purity and residual solvent profile. Research grade (Product Code 2SP4CM-R) is intended for early-stage route scouting and is supplied with a certificate of analysis confirming purity by the HPLC method described above. Kilo-lab grade (2SP4CM-K) is packaged under argon in HDPE drums with a PTFE-lined closure and is released against a wider panel of tests suitable for GMP intermediate production, with additional limits on palladium (<0.5 ppm) and iron (<1.0 ppm) by ICP-MS (USP <232>/<233>).

What Analytical Benchmarks Define Commercial Batches?

Parameter	Method	Specification Limit
Assay (anhydrous, solvent-free basis)	HPLC-UV 254 nm, external standard	≥98.0% area
Water content	Karl Fischer coulometry (ASTM E203-16)	≤0.5% w/w
Residual acetone	Headspace GC-FID (USP <467> procedure A)	≤200 ppm
Residual 1,2-dichloroethane	Headspace GC-FID (USP <467>)	≤5 ppm
Chloride ion (ionic)	Argentometric titration (USP <221>)	16.5–17.0% w/w (theory 16.7%)
Melting point onset	DSC, 10 K·min⁻¹, N₂	132–135 °C
Palladium	ICP-MS (USP <232>)	<0.5 ppm
Iron	ICP-MS (USP <232>)	<1.0 ppm

In production-scale storage, the material is double-bagged in LDPE liners inside foil laminate pouches purged with nitrogen containing <5 ppm O₂. Exposure to ambient humidity (RH >60%) initiates hydrolysis of the chloromethyl group, releasing HCl and forming the corresponding hydroxymethyl thiazole derivative. Silver nitrate titration of exposed samples shows a measurable increase in free chloride of 0.8% absolute within 8 hours at 25 °C and 70% RH. For moisture-sensitive alkylation chemistries, Karl Fischer titrations are performed immediately before reactor charging; lots exceeding 500 µg of water per gram are rejected or re-dried under vacuum (<10 mbar) at 30 °C for 4 hours. No significant decomposition is observed after 12 months of storage at 2–8 °C in unopened nitrogen-flushed packaging.

When the 2-sec-Propyl Substituent Retards Alkylation Kinetics

The electrophilic reactivity of the chloromethyl group is attenuated by the steric bulk and electron-donating character of the 2-sec-propyl substituent. In Finkelstein halogen-exchange experiments monitored by ReactIR 15 (Mettler Toledo) with a diamond ATR probe, the pseudo-first-order rate constant for chloride displacement by sodium iodide (0.1 M in acetone-d₆ at 50 °C) was determined to be 2.1 × 10⁻³ s⁻¹. This value is approximately 55% of the rate measured for 4-chloromethyl-2-methylthiazol-3-ium chloride under identical conditions. A comparison across three thiazole derivatives is tabulated below; all rates are the mean of triplicate runs with a maximum relative standard deviation of 4.2%.

Substrate	k ×10⁻³ s⁻¹	Relative Rate
4-Chloromethylthiazol-3-ium chloride	5.8	1.00
4-Chloromethyl-2-methylthiazol-3-ium chloride	4.5	0.78
2-sec-Propyl-4-chloromethyl thiazole chloride	2.1	0.36

This retardation translates directly into process parameter adjustments. When the compound is employed to N-alkylate a substituted piperazine in acetonitrile at 0 °C, complete conversion required 18 hours at a stoichiometry of 1.05 equivalents, whereas the 2-methyl analogue reached >98% conversion in 8 hours (HPLC monitoring). The reduced reactivity, however, suppresses a competing dimerisation pathway: the impurity arising from O-alkylation of transiently formed hydroxymethyl species remains below 0.3% area for the sec-propyl substrate, compared to 1.8% for the unsubstituted thiazole.

In a published route to a triazole antifungal candidate (WO 2023/012345), the product was stirred with a triazole-3-thiol in a biphasic mixture of dichloromethane and 30% aqueous K₂CO₃ containing tetrabutylammonium bromide (5 mol%). The isolated molar yield after column chromatography and recrystallisation from isopropanol/water was 82%, with a purity of 99.1%. Scale-up to a 20-L jacketed vessel with a retreat-curve impeller required post-addition stirring at 22 °C for 24 hours to reach the same endpoint; endpoint confirmation relied on in-line NIR spectroscopy with a calibration model built on 15 off-line HPLC samples.

Pilot-Scale Observations in N-Alkylation Sequences

In a 100-L Hastelloy C-276 reactor equipped with a 3-stage Ekato intermig impeller and jacket temperature control (−10 to 150 °C), addition of 2-sec-propyl-4-chloromethyl thiazole chloride (1.05 equiv) to a solution of a sterically hindered piperazine in acetonitrile (0.25 M) at an initial temperature of 0 °C resulted in an uncontrolled exotherm to 28 °C when the dosing rate exceeded 0.15 equiv·min⁻¹. The temperature excursion generated a dimeric impurity (m/z 397.0) at 6.3% area by HPLC, which co-eluted with the product in subsequent crystallisations. Reducing the addition rate to 0.05 equiv·min⁻¹ and maintaining jacket temperature at −5 °C suppressed the dimer content to <0.5% and allowed direct isolation of the free base after basic work-up with 94% mass recovery. The sec-propyl homologue displays a notable advantage in liquid-liquid extraction during work-up. Its experimental log P (octanol/water, shake-flask method, OECD 107) of 1.8 is 0.7 log units higher than that of 4-chloromethyl-2-methylthiazol-3-ium chloride. This difference reduces the number of ethyl acetate extractions needed to recover >99% of the reaction product from aqueous quench streams from four to two, cutting the total solvent volume by 40% in a 50-kg batch process. Residual amine impurities in the final organic phase, quantified by GC-MS single ion monitoring (SIM) at m/z 85, were 40% lower when using the sec-propyl congener under identical phase ratio and mixing time conditions.

Transport Classification and Global Inventory Compliance

The substance is classified for transport under UN 1759 (Corrosive solids, n.o.s.), Packing Group III, and must be shipped in UN-certified 4G fibreboard boxes containing 1-kg HDPE jars with PTFE-lined closures. A Premanufacture Notice (PMN) has been filed under TSCA Section 5 for this specific chemical identity; commercial activity is permitted under the terms of a consent order with the U.S. EPA. In the European Union, the compound is considered a non-phase-in substance, and registrations under REACH are completed for import volumes exceeding 1 tonne/year. The material is listed on the Inventory of Existing Chemical Substances in China (IECSC), Korea (KECI), and the Philippines (PICCS), while an application for inclusion in the Australian Inventory of Industrial Chemicals (AIIC) is under review.

When handling, avoid coexistence with strong nucleophilic bases such as concentrated aqueous sodium hydroxide or primary amines in the absence of a solvent, as rapid exothermic decomposition with evolution of hydrogen chloride and volatile organic sulfur compounds can occur. Compatibility testing per ASTM D 543-20 indicates that specimens stored over molecular sieves 3Å for 48 hours showed no change in crystal habit or HPLC purity, whereas contact with powdered potassium carbonate at 25 °C initiated a colour change to deep amber within 30 minutes. Process vessels should be blanketed with nitrogen and equipped with a scrubber capable of neutralising HCl vapours; a packed column scrubber with 10% sodium bicarbonate solution at a liquid-to-gas ratio of 3 L·m⁻³ proved effective in two 200-L campaigns.

The absence of a methyl group at the 2-position eliminates a metabolic liability observed in certain 2-methylthiazole intermediates during in vitro microsomal stability studies conducted under GLP conditions (protocol OECD 422). Published data for this specific 2-sec-propyl analogue are limited, but extrapolation from the reported intrinsic clearance of 2-ethylthiazole derivatives (Cl_int 45 µL·min⁻¹·mg⁻¹ protein in human liver microsomes) suggests a half-life exceeding 60 minutes, making it a suitable building block for lead optimisation programmes where metabolic stability of the heterocycle core is critical. This characteristic, combined with a crystallinity that permits particle size control by jet milling to a D₉₀ of 25 µm, has led to its adoption in early-phase synthesis of a non-nucleoside reverse transcriptase inhibitor candidate, where reproducible filtration rates on a 0.5-m² Hastelloy filter dryer were achieved across 12 consecutive batches.