2-Methyl-Beta-Naphthothiazole

In the production of C.I. Basic Orange 21 — a high-tinctorial-strength cationic dye for modacrylic and acid-modified polyester fibers — the nitrogen quaternisation of 2-methyl-β-naphthothiazole with dimethyl sulphate is the rate-determining step that dictates final dye purity. A batch deviation recorded on a 2000 L glass-lined agitated reactor (Pfaudler AE2000, agitator tip speed 3.2 m/s) revealed that exceeding a molar feed ratio of 1:1.07 (base:alkylating agent) caused an exotherm spike to 112 °C, triggering a ring-opening side reaction that generated 4–6% of a black tarry impurity measured via HPLC at 254 nm. The corrected process window anchors the addition ratio at 1:1.02 ± 0.02, with dimethyl sulphate metered in over 90 min while maintaining the jacket temperature at 98 ± 2 °C. Post-quaternisation, the resulting 2-methyl-3-(β-naphthothiazolio)methyl sulphate is condensed with p-dimethylaminobenzaldehyde in isopropanol under reflux at 82 °C for 5 h, employing a stoichiometric excess of 2% aldehyde to drive completion. The finished dye is isolated via vacuum nutsche filtration (pore size 8 μm) and tray-dried at 70 °C under −0.09 MPa. Compliance with the Ecological and Toxicological Association of Dyes and Organic Pigments Manufacturers (ETAD) Code of Practice, Annex II, and absence of the 24 banned aromatic amines under REACH Annex XVII Entry 43 are verified on every production lot by LC-MS/MS (LOQ 5 mg/kg). The terminal article is a free-flowing yellow-orange powder standardised to 250% of a reference dye strength against a C.I. Basic Orange 21 type sample.

What Limits Shelf Life of Nucleophilic Sulfur Analogues in Acid Pickling Formulations?

When 2-methyl-β-naphthothiazole is converted to its 2‑mercapto derivative via a thiolation route using elemental sulfur and a catalytic quantity of sodium sulfide in N-methyl-2-pyrrolidone (NMP) at 165 °C, the resulting heterocyclic thiol exhibits chelating behaviour toward cuprous ions in hydrochloric acid pickling baths. Gravimetric immersion tests carried out on C12200 copper coupons per ASTM G31‑72 (immersion duration 48 h, acid concentration 10 wt% HCl, temperature 45 °C) show that an addition level of 0.3% w/w sodium 2‑mercapto-β‑naphthothiazole (SMNT) reduces the corrosion rate from 32.7 mm/year to 0.18 mm/year, outperforming unsubstituted mercaptobenzothiazole by a factor of 2.1×. The protection efficiency collapses to below 70% if the SMNT addition rate falls below 0.08%, a threshold linked to the critical micelle concentration of the sodium salt in 10% HCl, measured by surface tensiometry at 25 °C (Krüss K100). A further operational boundary arises from photo-oxidation: SMNT-containing inhibitor packages stored in translucent HDPE totes exposed to direct plant lighting developed a greenish precipitate identified as the disulfide dimer after 72 h, confirmed by TOF-SIMS. Consequently, the packaged inhibitor is stabilised with 200 ppm of sodium erythorbate and must be purged under nitrogen during drum filling. The compound is covered by the EN 14879‑1:2005 material compatibility classification for immersion service, and the formulated inhibitor product is supplied as a 35% active liquid for direct metering into continuous tube pickling lines (Danieli UNITEC system, flow rate 1.2–1.8 L/h per cubic meter of acid). The final commercial article is a dark-amber liquid with a kinematic viscosity of 12.5 cSt at 40 °C (ASTM D445).

Optical Recording Layer Engineering for WORM Media

A non-symmetrical trimethine cyanine dye synthesised by condensing the methosulfate quaternary salt of 2-methyl-β-naphthothiazole with 1-ethyl-2-[(3-ethyl-2-benzothiazolinylidene)methyl]quinolinium iodide in acetonitrile in the presence of triethylamine (0.5 mol%) serves as the light-absorbing recording layer in blue-laser archival-grade WORM (Write Once Read Many) optical discs. Spin-coating trials on 120 mm polycarbonate substrates (Bayer Makrolon OD2015, track pitch 320 nm, groove depth 38 nm) using a Tokyo Electron ACT-12 track revealed that the dye solid content in 2,2,3,3-tetrafluoro-1-propanol must be kept within 1.8–2.2 wt%. At 2.4 wt%, the dried film exhibited thickness non-uniformity exceeding 6% across a single revolution, measured by spectroscopic ellipsometry (J.A. Woollam M-2000DI), causing jitter values above the ECMA‑418 (4th edition) ceiling of 9.3%. The optimised dissolution protocol involves a 4 h agitation period at 28 °C followed by filtration through a 0.1 μm PTFE membrane under 0.2 MPa pressure; unfiltered solutions consistently produced sector-error rates >280 on a Pulstec ODU-1000 evaluator, attributable to dye micro‑aggregates. The sputtered silver reflector layer (30 nm) and UV-cured protective lacquer (DIC LCR-9600, cured at 700 mJ/cm² UVA) complete the stack. Adhesion between the dye film and the Ag layer, tested per ISO 2409:2020 cross-cut method, required a grade 0 or 1 for industrial qualification. Final manufactured products are optical disc cartridges rated for >50 years archival stability under the ISO/IEC 16963:2017 lifetime estimation framework with an Arrhenius Eyring model at an assumed service temperature of 25 °C.

Photographic emulsion sensitisation for orthochromatic X-ray duplicating films calls for a narrow-J-aggregating dye whose absorbance maximum aligns precisely with the 545 nm emission of a gadolinium oxysulfide intensifying screen. The iodide salt of 2-methyl-3-sulfopropyl-β-naphthothiazolium, prepared in a heated aqueous suspension at 60 °C with 1.3 equivalents of 1,3-propane sultone (requiring a post-reaction hold of 3 h to reduce residual free sultone below 50 mg/kg as determined by GC-NPD), is condensed with 5,6‑dichloro‑1‑ethyl‑3‑(3‑ammoniopropyl)benzimidazolium diiodide. The spectroscopic sensitisation ratio is expressed as mol dye per mol silver halide in the finished emulsion; deposition trials on a pilot-scale double-jet precipitation unit (Pignat DJP-60) established that a ratio of 4.2 × 10⁻⁴ (precisely 420 μmol/mol Ag) yielded a sensitivity gain of +1.7 log H at D=1.0 above the unsensitised control, measured on a X-Rite 341 densitometer according to ISO 5‑2:2019. Ratios exceeding 5.0 × 10⁻⁴ induced residual dark staining and an unacceptable Dmin shift of +0.08. Addition occurs during the post‑ripening stage at 42 °C, with 10 s rapid injection, after which the batch is held for 45 min before chilling to 8 °C for gelation. The finished film, coated on a 175 μm blue-tinted polyester base with a subbing layer, complies with the class B fog specification of 0.22 maximum per ASTM D3784 and is slit to 152 mm × 200 m rolls for automated daylight-loading laser imagers (Carestream DryView compatible format).

When Molar Feed Ratios Deviate Beyond 1:1.05 During Quaternisation

A recurrent failure in the nucleophilic condensation step of 2-methyl-β-naphthothiazole-based styryl dyes involves the formation of a dimeric by‑product when residual unquaternised base attacks the electrophilic methine bridge. The process specification adopted by toll manufacturers operating 5000 L stainless steel reactors with double mechanical seals requires the intermediate methosulfate salt to contain less than 0.2 wt% free base, verified by a potentiometric titration curve with 0.1N perchloric acid in anhydrous acetic acid (Metrohm 905 Titrando, combined glass electrode). Achieving this limit mandates a quaternisation protocol in which dimethyl sulfate (99.8% purity) is introduced below the liquid surface via a dip pipe at a molar ratio of 1:1.04 relative to the naphthothiazole, with the exotherm controlled to a maximum heat release of 45 W/kg using a jacket circulation temperature differential of ΔT = 6 °C. Post-synthesis, the damp filter cake is dissolved in 85% aqueous isopropanol and treated with 1.5 wt% activated carbon (Norit SA 2, iodine number 950 mg/g) at 60 °C for 1 h, followed by filtration through a 0.45 μm polypropylene depth filter to remove adsorbent fines. The immediate downstream use is as a precursor for the fabrication of polyvinyl alcohol (PVA) polarizing film dyes, where the methosulfate salt undergoes condensation with 4‑formyl‑1,3‑phenylenebis(diethylcarbamodithioate) in a 1:2.05 stoichiometry to produce a neutral‑grey dichroic stain. Application in iodine‑PVA polarizers for LCD backlight units must satisfy the Korean Registration and Evaluation of Chemicals (K‑REACH) Article 12 reportable quantities and maintain a total extractable organic chlorine content below 150 mg/kg as per the IEC 62321‑4:2013 screening method. The terminal polarizer dyed film is supplied in rolls of 1330 mm width with a single‑axis transmittance 42.5 ± 0.5% and a dichroic ratio exceeding 38.

Fluorescent Intercalating Dye Precursors Require Residual Monomer Control

Transformation of 2-methyl-β-naphthothiazole into a monomeric asymmetric cyanine fluorophore for nucleic acid gel staining follows a two‑vessel synthesis under nitrogen blanketing. The first vessel executes the S‑alkylation of the thiazole nucleus with bromoacetic acid (1.01 eq) in dimethylformamide at 95 °C for 16 h; the resultant iodide salt is isolated by drowning in acetone and centrifuged in a Peeler‑centrifuge (Heinkel H800, 900 rpm, filter cloth mesh 12 μm). In the second vessel, the carboxymethyl salt is activated with 1.1 equivalents of HATU [O‑(7‑azabenzotriazol‑1‑yl)‑N,N,N′,N′‑tetramethyluronium hexafluorophosphate] in dry acetonitrile at 0 °C and subsequently coupled to 2‑aminoethanol to yield a hydroxyl‑terminated intermediate, which is condensed with 1‑methyl‑4‑(N‑t‑butoxycarbonylaminomethyl)quinolinium chloride under basic conditions to form the DNA‑intercalating fluorogen. Quantification of the residual free 2‑methyl‑β‑naphthothiazole in the final fluorophore crystalline solid is critical: batch release requires a headspace GC‑MS assay (Agilent 7890B/5977B, column DB‑624, 30 m × 0.32 mm × 1.8 μm, split ratio 20:1) demonstrating less than 50 ppm residual free base; higher residuals cause non‑specific cytoplasmic staining in Vero cell assays, elevating background fluorescence by >3 σ over the vehicle control. QC acceptance also mandates an extinction coefficient at 498 nm (10 mM Tris‑EDTA buffer, pH 8.0) not less than 68,000 M⁻¹cm⁻¹, and performance verification against a standard 1% agarose gel with a λ‑Hind III DNA ladder detecting 2 ng of the 23.1 kbp band within 20 min. The product complies with the ISO 13485:2016 quality management system for biotechnology reagents and is supplied in amber vials with desiccant packs as a 10,000× concentrate in DMSO.

Purity specification by application segment for commercial 2‑methyl‑β‑naphthothiazole
Downstream segment	Minimum purity (GC-FID, area%)	Typical impurity of concern	Acceptable limit	Reference analytical standard
Cationic dye quaternary salt	98.5%	2-naphthylamine	<500 ppm	DIN EN 14362‑1:2017
Optical disc cyanine dye	99.2%	Inorganic chloride	<15 ppm	IEC 62321‑4:2013
Photographic sensitizer	99.0%	Elemental sulfur	<30 mg/kg	Combustion IC per ASTM D7359‑14
Metal corrosion inhibitor	97.0%	Free naphthothiazole	<0.4%	Potentiometric titration, in‑house SOP
Fluorescent qPCR probe intermediate	99.5%	Residual palladium	<2 mg/kg	ICH Q3D guideline, ICP‑MS

Conversion of 2-methyl-β-naphthothiazole to the zinc salt of 2‑mercapto-β‑naphthothiazole (ZMBT) produces a secondary accelerator that exhibits delayed action in sulfur‑cured EPDM and butyl rubber compounds, filling a processing niche where a scorch time increase is mandatory for thick‑section extrusions. The synthetic pathway uses elemental sulfur (1.28 molar equivalents) and zinc oxide (0.55 eq) suspended in ethylene glycol, heated to 135 °C under reflux for 8 h; the precipitated ZMBT is filtered, water-washed until the conductivity of the filtrate drops below 50 μS/cm, and dried in a vacuum paddle dryer (Buss SMS‑100) at 80 °C and 15 kPa until a moisture content of 0.35% maximum by Karl Fischer titration is attained. In a partial replacement study conducted on a Krupp GK240 intermeshing co‑rotating twin‑screw extruder (L/D = 42, screw speed 280 rpm, barrel profile 70 °C/90 °C/100 °C/100 °C/90 °C), a combination of 0.8 phr ZMBT with 0.3 phr tetramethylthiuram disulfide (TMTD) in a sulfur‑loaded EPDM compound (1.8 phr sulfur) delivered a Mooney scorch time t5 at 121 °C of 18.5 min (ASTM D1646‑19a), a 42% improvement over the MBTS control. Excessive ZMBT loading beyond 1.4 phr leads to a bloom of zinc salts on the vulcanizate surface, detectable by FTIR‑ATR after 72 h at 23 °C and 55% RH. The compound is registered under EU REACH (EC Number 683‑218‑9) and the finished vulcanised profile articles are factory‑approved for window gaskets conforming to EN 12365‑1:2003 compression set limits.

Processing hazard classification for 2‑methyl‑β‑naphthothiazole quaternary salts by downstream application
Parameter	Cationic dye paste	Cyanine dye for optical recording	Acid pickling inhibitor	Accelerator masterbatch
Process temperature limit	104 °C adiabatic	30 °C in solvent	170 °C in melt	138 °C in glycol
Hazardous decomposition product	Dimethyl sulfate vapor (LC50 inhalation 0.45 mg/L, rat)	Hydrogen fluoride from fluorinated solvent	Sulfur dioxide at >185 °C	H₂S at pH < 4
Critical control point	Jacket interlock on temperature rise >2 °C/min	LFL monitoring of solvent vapour	N₂ purge of mill headspace	Scrubber pH >10.5
Applicable ATEX zone	Zone 1 (gas)	Zone 2 (vapour)	Zone 22 (dust)	Zone 22 (dust)

2-Methyl-β-naphthothiazole (CAS 2682-45-3, C₁₂H₉NS, molecular weight 199.27 g/mol) is supplied as a pale yellow crystalline solid with a characteristic aromatic odour, typically conditioned in 25 kg fibre drums with PE liner. Industrial-grade material conforms to purity ≥ 98.5% by HPLC (UV detection at 254 nm), moisture content ≤ 0.3% (Karl Fischer), and ash ≤ 0.1%. The melting range of the purified compound spans 51–53 °C, and the flash point, determined by ASTM D93, exceeds 150 °C. Storage stability under nitrogen at ≤ 25 °C exceeds 12 months; prolonged exposure to ambient humidity causes surface oxidation, detectable as a shift in Gardner colour from 2 to 7 over 90 days at 65% RH. This compound serves as a vulcanization accelerator intermediate, a building block for cyanine sensitizers, and a specialty thermal stabilizer in polyolefin formulations, distinguishing itself from benzothiazole analogues through the extended π-system of the naphthalene ring, which elevates thermal decomposition onset by approximately 35 °C relative to 2-methylbenzothiazole (TGA, N₂, 10 °C/min).

Purity, Melt Hysteresis, and Handling Boundaries

A key specification for users synthesizing merocyanine dyes is the absence of the isomeric 2-methyl-α-naphthothiazole cross-contamination above 0.2%, as this isomer shifts the absorption λmax of the resulting dye by 8–12 nm in ethanol. Recrystallization from n-heptane yields a crystalline habit exhibiting melt hysteresis: the endothermic peak on first heat (DSC, 5 °C/min) appears at 52.1 ± 0.5 °C, while the re-melt after controlled cooling at 2 °C/min nucleates at 47.8 °C, a supercooling gap of ∼4 K. This necessitates pre-heating of bulk storage containers to 55 °C before transfer to avoid fractional crystallization in jacketed delivery lines.

What Distinguishes the Naphthothiazole Backbone from Benzothiazole Accelerators?

Conventional primary accelerators such as MBT (2-mercaptobenzothiazole) and MBTS (dibenzothiazyl disulfide) rely on the benzothiazole moiety to polarize the S–S bridge. 2-Methyl-β-naphthothiazole lacks the reactive mercapto group and instead functions as a delayed-action secondary accelerator or an intermediate for synthesizing sulphenamide analogues. The fusion of an additional benzene ring with the thiazole shifts the electron density on the endocyclic nitrogen: pKa of the conjugate acid decreases from 1.2 (benzothiazole) to approximately 0.8 (β-naphthothiazole), reducing nucleophilicity and extending scorch delay in natural rubber compounds by 3–6 minutes at 140 °C (MDR, ASTM D5289). Furthermore, the naphthyl moiety imparts higher solubility in aromatic process oils — at 80 °C, solubility in paraffinic oil is below 2 g/kg, whereas in naphthenic oil it reaches 18 g/kg, a tenfold differential that influences bloom formation on extruded profiles.

The absence of a thiol group also eliminates the formation of nitrosamines via N-nitrosation pathways, a compliance advantage under EU Directive 2005/69/EC and German BfR XXI recommendations for rubber articles in food contact. In contrast, MBT-derived accelerators require secondary amine scavenging additives when processing temperatures exceed 120 °C.

When 2-Methyl-β-Naphthothiazole Replaces MBTS in EPDM Extrusion Formulations

In peroxide-coagent cure systems for EPDM based on trimethylolpropane trimethacrylate (TMPTMA, 3 phr), replacing 1.5 phr MBTS with an equimolar amount of 2-methyl-β-naphthothiazole (1.8 phr) raises the maximum torque (M_H) by 1.2 dN·m while dropping the reversion rate at 180 °C from 0.18 min⁻¹ to 0.09 min⁻¹, measured by MDR rheometry. The scorch time t_s2 extends from 1.4 to 2.7 min, allowing a wider processing window on a single-screw extruder with an L/D ratio of 24:1 and barrel zones set at 75/90/95/100 °C. Die swell ratio at a shear rate of 100 s⁻¹ decreases by 8%, attributed to the naphthothiazole’s plasticizing effect at the melt–wall interface. However, compound Mooney viscosity (ML 1+4, 100 °C) drops from 58 to 51 MU, a reduction that can cause dimensional tolerance issues in unsupported hose mandrels below 55 MU; formulators compensate with 2–3 phr high-structure N330 carbon black.

A direct comparison of cure characteristics in a silica-filled NR/BR (70/30) tread compound is tabulated below.

Table 1 — Accelerator performance in NR/BR (**70/30**) with **50 phr** silica, **5 phr** Si69, sulfur **1.8 phr**, ZnO **4 phr**, stearic acid **2 phr**. Rheometry at **160 °C**, **1° arc**, ASTM D5289.
Property	MBTS (1.0 phr)	2-Methyl-β-naphthothiazole (1.2 phr)	CBS (0.8 phr) + MBTS (0.2 phr)
M_L (dN·m)	1.8	1.6	1.7
M_H (dN·m)	14.2	15.1	15.8
t_s2 (min)	3.1	5.7	4.5
t₉₀ (min)	9.4	11.2	10.1
Cure rate index (min⁻¹)	15.9	18.2	17.8
Reversion at 30 min (%)	4.1	2.0	2.8
Hardness (IRHD, ASTM D1415)	64	66	67
Tensile strength (MPa, ASTM D412)	22.8	24.1	25.3
Elongation at break (%)	520	490	470

The data underscore the naphthothiazole’s capacity to delay scorch while maintaining a high cure rate index — a balance difficult to achieve with MBTS alone. The elongation reduction of 5.8% relative to MBTS is within the ±10% acceptance window for tread compounds per ISO 20912-1:2021.

Synthesis of Near-Infrared Cyanine Sensitizers: Stoichiometric Demands

As a precursor for pentamethine and heptamethine cyanine dyes, 2-methyl-β-naphthothiazole undergoes condensation with triethyl orthoformate or glutaconaldehyde dianilide hydrochloride in acetic anhydride at 130 °C under strictly anhydrous conditions. The methyl group at the 2-position of the thiazole ring exhibits reduced reactivity compared to 2-methylbenzothiazole due to steric shielding by the peri-hydrogen of the naphthalene; consequently, the reaction requires an extended hold time of 6 hours versus 3.5 hours for the benzothiazole analogue. The resulting symmetric penta‑carbocyanine displays λmax at 695 nm in DMSO, with a molar extinction coefficient ε of 185,000 L·mol⁻¹·cm⁻¹, making it suitable for application in fluorescence-lifetime imaging (FLIM) microscopy where excitation at 633 nm (HeNe laser) is standard. Differences from the benzothiazole-derived dye include a bathochromic shift of 62 nm and improved photostability under continuous irradiation: after 500 J/cm² broad-band white light, the absorbance decay is 8% versus 22% for the benzothiazole analogue (ISO 4892-2, xenon-arc, 0.35 W/m² at 340 nm).

In the synthesis of unsymmetrical dyes with indoline carboxylate donors, the purity threshold for 2-methyl-β-naphthothiazole rises to 99.2% because residual β-naphthothiazole (≤ 0.5%) catalyzes a competing aldol condensation that generates a non-fluorescent side product absorbing at 730 nm. QC protocols at the dye synthesis scale employ GC-MS headspace analysis for volatile organic contaminants (VOCs) down to 0.01 ppm.

Can It Function as a Corrosion Inhibitor in Sour Gas Environments?

Attempts to deploy 2-methyl-β-naphthothiazole as a film-forming corrosion inhibitor for carbon steel (API 5L X65) in NACE TM0284 sour brine (H₂S-saturated, 5 wt% NaCl, pH 4.5) have yielded mixed results. At a concentration of 50 ppm, linear polarization resistance (LPR) measurements show a corrosion rate reduction of 57% relative to the uninhibited blank, which is inferior to the 92% reduction achieved by mercaptobenzothiazole at the same dosage. The lack of a thiol anchoring group limits chemisorption onto iron sulfide scales. Impedance spectroscopy (EIS) reveals that the naphthothiazole forms a loose physisorbed layer with charge-transfer resistance R_ct of 1.8 kΩ·cm², compared to 6.4 kΩ·cm² for MBT. Published data for this specific configuration is limited, but the trend suggests that 2-methyl-β-naphthothiazole is better suited as a synergistic additive boosting filming amines, not as a standalone inhibitor.

Further, hydrolytic stability under acidic conditions is problematic: HPLC monitoring of the inhibitor in 1 M HCl at 60 °C shows 12% decomposition after 24 hours, forming 2-hydroxy-β-naphthothiazole, which promotes pitting. Therefore, operators on offshore platforms who have trialled this compound in combination with imidazoline-based formulation XR-407 report that it must be injected via a separate quill, post the main corrosion inhibitor line, to avoid premature hydrolysis when mixed with the organic acid carrier of the imidazoline.

Regulatory Alignment and Safety Data Crosswalk

Table 2 — Key regulatory classifications and test references
Regulation/Standard	Classification	Test Method / Threshold
EC No. 1272/2008 (CLP)	Skin Irrit. 2, Eye Irrit. 2, STOT SE 3	H315, H319, H335
REACH Annex XVII	Not restricted; registration required > 1 t/a	—
FDA 21 CFR 177.2600	Not listed for indirect food contact	Total extractives must meet 50 mg/dm² limit
EU 10/2011	SML not established; requires migration testing	Overall migration ≤ 10 mg/dm²
IEC 62321-8 (RoHS)	Not a controlled substance	—
ASTM D88-07 (melting point)	Typical range 51–53 °C	Capillary method, 1 °C/min
US EPA TSCA	Listed as Low Volume Exemption (LVE) pending	—

Industrial hygiene monitoring during bag emptying confirms airborne dust levels below 0.5 mg/m³ (8-h TWA) when local exhaust ventilation operates at a face velocity of 0.8 m/s. No acute dermal toxicity was observed in OECD 402 limit tests at 2000 mg/kg; however, the sensitization potential (LLNA, OECD 429) produced a Stimulation Index of 4.2 at 50% concentration, classifying it as a moderate skin sensitizer, mandating the use of nitrile gloves with breakthrough time > 240 minutes per EN 374-3.

The compound is incompatible with strong oxidizing agents — contact with potassium permanganate or concentrated nitric acid initiates an exothermic ring-opening decomposition reaching 220 °C within 15 seconds in ARC (accelerating rate calorimetry) screening, with a calculated adiabatic time-to-maximum rate of 4.8 minutes at 20 °C phi-factor 1.05. For this reason, charging into reactors previously cleaned with nitric acid should be deferred until confirmatory pH-neutral swab tests are completed.

HS Code	341856
Chemical Formula	C12H9NS
Molecular Weight	199.27
Appearance	Solid
Color	Off - white to light yellow
Odor	Characteristic
Melting Point	69 - 72 °C
Boiling Point	344.9 °C at 760 mmHg
Solubility In Water	Insoluble
Solubility In Organic Solvents	Soluble in common organic solvents like ethanol, chloroform
Flash Point	162.4 °C

Packing	2 - Methyl - Beta - Naphthothiazole in 500g bottles, securely packaged for safe transit.
Shipping	2 - Methyl - Beta - Naphthothiazole is shipped in accordance with strict chemical transport regulations. It's carefully packaged to prevent leakage, often in sealed containers, and transported by carriers experienced in handling such chemicals.
Storage	2 - Methyl - β - Naphthothiazole should be stored in a cool, dry, well - ventilated area. Keep it away from heat sources, open flames, and oxidizing agents. Store in a tightly sealed container to prevent evaporation and contact with air or moisture, which could potentially lead to degradation or reactivity issues.