3864-99-1

Basic information

• Product Name: 2-(2'-Hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole
• Synonyms: 2-(2’-hydroxy-3’,5’-ditertbutylphenyl)-5-chloro-benzotrizole;2-(5-chloro-2h-benzotriazol-2-yl)-4,6-bis(1,1-dimethylethyl)-pheno;4-di-tert-butyl-6-(5-chloro-2h-benzo-triazol-2-;Phenol,2-(5-chloro-2H-benzotriazol-2-yl)-4,6-bis(1,1-dimethylethyl)-;5-CHLORO-2-(3,5-DI-TERT-BUTYL-2-HYDROXYPHENYL)BENZOTRIAZOLE;2-(3,5-DI-TERT-BUTYL-2-HYDROXYPHENYL)-5-CHLORO-2H-BENZOTRIAZOLE;2-(3',5'-DI-TERT-BUTYL-2'-HYDROXYPHENYL)-5-CHLOROBENZOTRIAZOLE;2-(3,5-DI-TERT-BUTYL-2-HYDROXYPHENYL)-5-CHLOROBENZOTRIAZOLE
• CAS NO: 3864-99-1
• Molecular Formula: C₂₀H₂₄ClN₃O
• Molecular Weight: 357.88
• EINECS: 223-383-8
• Product Categories: Organics;Polymer Additives;Polymer Science;Stabilizers;Polymer Additives;Polymer Science
• Mol File: 3864-99-1.mol

Chemical Properties

• Melting Point: 150-153 °C(lit.)
• Boiling Point: 469.2 °C at 760 mmHg
• Flash Point: 234°C
• Appearance: /
• Density: 1,26 g/cm3
• Vapor Pressure: 2E-09mmHg at 25°C
• Refractive Index: 1.596
• Storage Temp.: Keep in dark place,Sealed in dry,Room Temperature
• Solubility: Chloroform, Ethyl Acetate (Slightly), Methanol (Slightly)
• PKA: 9.23±0.48(Predicted)
• CAS DataBase Reference: 2-(2'-Hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole(CAS DataBase Reference)
• NIST Chemistry Reference: 2-(2'-Hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole(3864-99-1)
• EPA Substance Registry System: 2-(2'-Hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole(3864-99-1)

Safety Data

• Hazard Codes: Xi
• Statements: 36/37/38
• Safety Statements: 26-36
• RIDADR: 3077
• WGK Germany: 2
• RTECS: 3425000
• TSCA: Yes
• HazardClass: 9
• Hazardous Substances Data: 3864-99-1(Hazardous Substances Data)

Usage

Uses

2,4-Di-tert-butyl-6-(5-chloro-2H-benzotriazol-2-yl)phenol is a UV absorber.

InChI:InChI=1/C20H24ClN3O/c1-19(2,3)12-9-14(20(4,5)6)18(25)17(10-12)24-22-15-8-7-13(21)11-16(15)23-24/h7-11,25H,1-6H3

Synthetic route

2-nitro-4-chloro-2'-hydroxy-3',5'-di-tert-butylazobenzene (52184-29-9) → 2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol (3864-99-1)

Conditions	Yield
With hydrogen; potassium hydroxide; sodium hydroxide In 1,4-dioxane; water at 100℃; under 750.075 Torr; Autoclave;	97.95%
With borane-ammonia complex In toluene at 50℃; for 5h;	95.6%
With sodium hydroxide; thiourea dioxide In ethanol at 85 - 90℃; for 1h;	80%

2-(6-chloro-1-oxido-2H-benzotriazol-2-yl)-4,6-bis(1,1-dimethylethyl)phenol (84755-45-3) → 2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol (3864-99-1)

Conditions	Yield
With sodium hydroxide In tetrahydrofuran; water electrolysis, Pt cathode and anode;	97%
With potassium hydroxide; lithium perchlorate In tetrahydrofuran; water at 20℃; Reduction; Electrolysis;	97%
With sodium hydroxide; bakers' yeast In ethanol 1.) r.t., 30 min, 2.) 80-85 deg C, 24 h;	89%

2,4-Di-tert-butyl-6-(4-chloro-2-nitro-phenylazo)-phenol (52184-29-9) → 2-(6-chloro-1-oxido-2H-benzotriazol-2-yl)-4,6-bis(1,1-dimethylethyl)phenol (84755-45-3) + 2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol (3864-99-1)

Conditions	Yield
With sodium hydroxide; thiourea S,S-dioxide In water; isopropyl alcohol for 3h; Heating;	A 0.3% B 95%
With sodium hydroxide; Beakers' yeast In ethanol at 85℃; for 24h; Product distribution; various amounts of bakers' yeast and NaOH; various times; pH; reagents;	A 29% B 65%

C20H26ClN3O2 → 2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol (3864-99-1)

Conditions	Yield
With sodium phosphite; hydrogen; dibutylamine at 60℃; under 7500.75 Torr; for 12h; Reagent/catalyst; Temperature; Pressure; Autoclave;	94.2%

C20H24ClN3O2 → 2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol (3864-99-1)

Conditions	Yield
With platinum on activated charcoal; hydrogen at 50 - 75℃; under 3750.38 - 6000.6 Torr; Autoclave;	92.4%

2-Nitro-4-chloro-2'-hydroxy-3',5'-di-tert-butyl-azobenzene → 2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol (3864-99-1)

Conditions	Yield
With sodium hydroxide In tetrahydrofuran; water electrolysis, Pt cathode and anode;	92%
With sodium hydroxide; zinc In water at 90℃; for 1h;	90%
	75%
With samarium diiodide In tetrahydrofuran for 2.7h; Ambient temperature;	84 % Spectr.
Multi-step reaction with 2 steps 1: 0.4 M LiClO4 / methanol; CH2Cl2 / electrolysis, Pt cathode and anode using a devised H cell 2: 97 percent / 0.2 M NaOH / tetrahydrofuran; H2O / electrolysis, Pt cathode and anode View Scheme

2,4-Di-tert-butyl-6-(4-chloro-2-nitro-phenylazo)-phenol (52184-29-9) → 2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol (3864-99-1)

Conditions	Yield
With sodium hydroxide; bakers' yeast In ethanol 1.) r.t., 30 min, 2.) 80-85 deg C, 40 h;	85%
With sodium hydroxide In isopropyl alcohol at 85℃; for 24h; Reduction; Cyclization; Irradiation;	83%
Multi-step reaction with 2 steps 1: 29 percent / Beakers' yeast, aq. NaOH / ethanol / 24 h / 85 °C / various amounts of bakers' yeast and NaOH; various times; pH; reagents 2: 89 percent / aq. NaOH, bakers' yeast / ethanol / 1.) r.t., 30 min, 2.) 80-85 deg C, 24 h View Scheme
Multi-step reaction with 2 steps 1: 85 percent / aq. NaOH, bakers' yeast / ethanol / 1.) r.t., 30 min, 2.) 80-85 deg C, 4 h 2: 89 percent / aq. NaOH, bakers' yeast / ethanol / 1.) r.t., 30 min, 2.) 80-85 deg C, 24 h View Scheme

C20H24Cl2N2O → 2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol (3864-99-1)

Conditions	Yield
With sodium azide; triethylamine; copper(I) bromide In DMF (N,N-dimethyl-formamide) at 80℃; for 4h;	84%

iso-butanol (78-92-2, 15892-23-6) + 2-(5-chloro-1-oxido-2H-benzotriazol-2-yl)-4,6-bis(1,1-dimethylethyl)phenol (94102-13-3) → 2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol (3864-99-1)

Conditions	Yield
With tributyl-amine; aluminum nickel In water; hydrogen; toluene	79.2%

1,5-diazabicyclo [5.4.0] undecene + iso-butanol (78-92-2, 15892-23-6) + 2-(5-chloro-1-oxido-2H-benzotriazol-2-yl)-4,6-bis(1,1-dimethylethyl)phenol (94102-13-3) → 2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol (3864-99-1)

Conditions	Yield
With hydrogen; aluminum nickel In nitrogen; toluene	79%

2-nitro-5-chloro-2'-hydroxy-3',5'-di-tert-butylazobenzene → 2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol (3864-99-1)

Conditions	Yield
With samarium diiodide In tetrahydrofuran for 0.666667h; Ambient temperature;	91 % Spectr.

2-nitro-4-chloro-2'-hydroxy-3',5'-di-tert-butylazobenzene (52184-29-9) → 4-Chloro-1,2-phenylenediamine (95-83-0) + 2-amino-4,6-di-tertbutylphenol (1643-39-6) + 2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol (3864-99-1)

Conditions	Yield
With 2-bromo-2-nitropropane; zinc In methanol; dichloromethane for 4h; Ambient temperature;	A n/a B n/a C 88 % Chromat.

2,4-di-tert-butyl-6-(5-chloro-2-nitro-phenylazo)-phenol → 4-Chloro-1,2-phenylenediamine (95-83-0) + 2-amino-4,6-di-tertbutylphenol (1643-39-6) + 2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol (3864-99-1)

Conditions	Yield
With 2-bromo-2-nitropropane; zinc In methanol; dichloromethane for 3.5h; Ambient temperature;	A n/a B n/a C 79 % Chromat.

2,4-di-tert-butyl-6-(5-chloro-2-nitro-phenylazo)-phenol → 2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol (3864-99-1)

Conditions	Yield
With sodium hydroxide; lithium perchlorate In tetrahydrofuran; water at 20℃; Cyclization; Electrolysis;	98 % Chromat.

2,4-di-tert-Butylphenol (96-76-4) → 2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol (3864-99-1)

Conditions	Yield
Multi-step reaction with 3 steps 1: 2.) 1N HCl, sodium lauryl sulfate / 1.) diazotation, 2.) 45 deg C, 6 h 2: 84 percent / glucose, 2N NaOH / ethanol / 1 h / Heating 3: 88 percent / Zn, 2N NaOH / ethanol / 1 h / Ambient temperature View Scheme

4-Chloro-2-nitroaniline (89-63-4) → 2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol (3864-99-1)

Conditions	Yield
Multi-step reaction with 3 steps 1: 2.) 1N HCl, sodium lauryl sulfate / 1.) diazotation, 2.) 45 deg C, 6 h 2: 84 percent / glucose, 2N NaOH / ethanol / 1 h / Heating 3: 88 percent / Zn, 2N NaOH / ethanol / 1 h / Ambient temperature View Scheme

7H-benz[d,e]anthracene-7-one (82-05-3) + acetaldehyde (75-07-0) + 2-(5-chloro-1-oxido-2H-benzotriazol-2-yl)-4,6-bis(1,1-dimethylethyl)phenol (94102-13-3) → 2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol (3864-99-1)

Conditions	Yield
With sodium hydroxide In methanol; water
With sodium hydroxide In methanol; water

diethylene glycol diethyl ether + 2-Nitro-4-chloro-2'-hydroxy-3',5'-di-tert-butyl-azobenzene → 2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol (3864-99-1)

Conditions	Yield
With hydrogenchloride; sodium hydroxide; nitrogen; hydrazine hydrate In water

2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol (3864-99-1) + methyl iodide (74-88-4) → 2-[3,5-bis(1,1-dimethylethyl)-2-methoxyphenyl]-5-chloro-2H-benzotriazole (271788-60-4)

Conditions	Yield
With potassium carbonate In acetone at 45℃; for 72h;	99.8%

2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol (3864-99-1) → 2-bromo-4-(tert-butyl)-6-(5-chloro-2H-benzo[d][1,2,3]triazol-2-yl)phenol

Conditions	Yield
With bromine; trifluoroacetic acid at 65℃; for 2h;	99%

4-trifluoromethylphenylboronic acid (128796-39-4) + 2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol (3864-99-1) → C27H28F3N3O

Conditions	Yield
With O4P(3-)*3K(1+)*5H2O; tris(1-adamantyl)phosphine; C28H26N2O8Pd2S2; potassium tert-butylate In tetrahydrofuran at 70℃; for 5h; Suzuki-Miyaura Coupling; Inert atmosphere; Schlenk technique;	96%
With O4P(3-)*3K(1+)*5H2O; tris(1-adamantyl)phosphine; {2-[((acetyl-κO)amino)phenyl-κC](tri-1-adamantylphosphine)palladium}(p-toluenesulfonate); potassium tert-butylate In tetrahydrofuran at 70℃; for 5h; Suzuki-Miyaura Coupling; Inert atmosphere;	96%

di-tert-butyl dicarbonate (24424-99-5) + 2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol (3864-99-1) → carbonic acid tert-butyl ester 2,4-di-tert-butyl-6-(5-chlorobenzotriazol-2-yl)phenyl ester

Conditions	Yield
With pyridine for 2h; Heating;	93.4%

sodium tungstate + thiophenol (108-98-5) + 2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol (3864-99-1) → 5-benzenesulfonyl-2-(2-hydroxy-3,5-di-tert-butylphenyl)-2H-benzotriazole

Conditions	Yield
With 1-methyl-pyrrolidin-2-one; hydrogenchloride; potassium hydroxide; formic acid; dihydrogen peroxide In methanol; 5,5-dimethyl-1,3-cyclohexadiene; water	88.6%

zirconium(IV) tetraisopropoxide 2-propanol (14717-56-7) + 2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol (3864-99-1) → C80H92Cl4N12O4Zr (1491152-54-5)

Conditions	Yield
In toluene at 70℃; for 36h; Schlenk technique; Inert atmosphere;	84%

2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol (3864-99-1) → 2-(6-chloro-1-oxido-2H-benzotriazol-2-yl)-4,6-bis(1,1-dimethylethyl)phenol (84755-45-3)

Conditions	Yield
With sodium hydroxide; thiourea dioxide In ethanol at 80℃; for 1h;	80%

zirconium(IV) tetraisopropoxide 2-propanol (14717-56-7) + 2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol (3864-99-1) → C58H88Cl2N6O8Zr2 (1491152-51-2)

Conditions	Yield
In toluene at -24℃; Schlenk technique; Inert atmosphere;	80%

hafnium(IV) tert-butoxide + 2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol (3864-99-1) → C80H92Cl4HfN12O4 (1491152-57-8)

Conditions	Yield
In toluene at 70℃; for 24h; Schlenk technique; Inert atmosphere;	79%

benzoyl chloride (98-88-4) + 2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol (3864-99-1) → benzoic acid 2,4-di-tert-butyl-6-(5-chlorobenzotriazol-2-yl)phenyl ester

Conditions	Yield
With pyridine for 2h; Heating;	77%

tantalum pentachloride (7721-01-9) + 2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol (3864-99-1) → C20H23Cl5N3OTa

Conditions	Yield
Stage #1: tantalum pentachloride; 2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol In toluene at 0℃; Inert atmosphere; Schlenk technique; Glovebox; Stage #2: In toluene at 20℃; for 12h; Inert atmosphere; Schlenk technique; Glovebox;	76%

niobium pentachloride (10026-12-7) + 2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol (3864-99-1) → C20H23Cl5N3NbO

Conditions	Yield
Stage #1: niobium pentachloride; 2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol In toluene at 0℃; Inert atmosphere; Schlenk technique; Glovebox; Stage #2: In toluene at 20℃; for 12h; Inert atmosphere; Schlenk technique; Glovebox;	75%

2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol (3864-99-1) → 2-(2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol (3846-71-7)

Conditions	Yield
With sodium hydroxide; zinc In ethanol for 5h; Heating;	73%

2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol (3864-99-1) → 2-(2'-hydroxy-phenyl)-5-chlorobenzotriazole (23624-49-9)

Conditions	Yield
With aluminium trichloride; nitromethane In toluene for 7h; Heating;	71%

2-(5'-chloro-2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol (3864-99-1) + 2-hydroxyethanethiol (60-24-2) → C22H29N3O2S

Conditions	Yield
With potassium iodide; potassium hydroxide In 1-methyl-pyrrolidin-2-one at 100℃; for 6h;	43%

Upstream product

• 52184-29-9 2-nitro-4-chloro-2'-hydroxy-3',5'-di-tert-butylazobenzene 
• 52184-29-9 2,4-Di-tert-butyl-6-(4-chloro-2-nitro-phenylazo)-phenol 
• 89-63-4 4-Chloro-2-nitroaniline 
• 78-92-2 iso-butanol 
• 94102-13-3 2-(5-chloro-1-oxido-2H-benzotriazol-2-yl)-4,6-bis(1,1-dimethylethyl)phenol 
• 82-05-3 7H-benz[d,e]anthracene-7-one 
• 75-07-0 acetaldehyde 
• 84755-45-3 2-(6-chloro-1-oxido-2H-benzotriazol-2-yl)-4,6-bis(1,1-dimethylethyl)phenol 
• 96-76-4 2,4-di-tert-Butylphenol 

Downstream Products

• 84755-45-3 2-(6-chloro-1-oxido-2H-benzotriazol-2-yl)-4,6-bis(1,1-dimethylethyl)phenol 
• 23624-49-9 2-(5-chloro-benzotriazol-2-yl)-phenol 
• 3846-71-7 2-(2'H-benzotriazol-2'-yl)-4,6-di-tert-butylphenol 
• 145233-43-8 2-(3',5'-di-tert-butyl-2'-hydroxyphenyl)-5-(phenylthio)benzotriazole 
• 145233-57-4 5,5'-Thiobis-[2-(2-hydroxy-3,5-di-tert-butylphenyl)-2H-benzotriazole] 

Relevant articles and documents

Preparation method of benzotriazole ultraviolet light absorber

The invention relates to a preparation method of a benzotriazole ultraviolet absorbent. The method comprises the following steps: under the action of a magnesium oxide supported metal catalyst, carrying out transfer hydrogenation reaction on an azo intermediate shown in a formula I and a hydrogen donor to obtain a target product shown in a formula III. The method provided by the invention is small in catalyst dosage, the raw material conversion rate can reach 100%, and the target product selectivity is 90% or above.

NOVEL PROCEDURE FOR THE FORMATION OF 2H-BENZOTRIAZOLE BODIES AND CONGENERS

The present invention relates to a process for the preparation of 2H-benzotriazole compounds and congeners, novel 2H-benzotriazole compounds and congeners and their use as UV absorbers in coatings and bulk plastics.

A benzo triazole ultraviolet absorbing agent preparation method (by machine translation)

The invention discloses a benzo triazole ultraviolet absorbing agent preparation method, including the raw material compound and alkali is dissolved in the solvent, is configured to raw material is added to the reaction device; then the Fe3 O4 /Catalyst is added to the raw material liquid in the graphene, access hydrogen, keeping the pressure 0.1 - 5 mpa, temperature 40 - 120 °C; in the reaction process using high performance liquid chromatography to real-time monitoring of the reaction solution, after the reaction, cooling, the restoration of normal pressure and recovering the catalyst after treatment, be benzo triazole ultraviolet absorbent. The method of this invention simple process, environmental protection, low cost, mild reaction conditions, product yield and quality is high, is suitable for industrial production, Fe used therein3 O4 /Graphene catalyst economic and environmental protection, stable properties, is recycled. (by machine translation)

A benzotriazole compound synthesis method (by machine translation)

The invention discloses a synthetic method of a benzotriazoles compound. The synthetic method comprises the following steps: loading a bifunctional catalyst of hydrogenation-solid alkali into a fixed bed reactor; continuously leading a solution of a compound represented by the formula (I) into the fixed bed reactor, leading hydrogen, and performing heating; enabling the reaction liquid to continuously flow out from a lower end of the fixed bed reactor; cooling the effluent reaction liquid to the room temperature; performing gas-liquid separation, liquid filtration, and filtrate condensation to remove the solvent; and performing purification to obtain the benzotriazoles compound represented by the formula (II). The bifunctional catalyst of hydrogenation-solid alkali is adopted for catalytic hydrogenation to synthesize the benzotriazoles compound. The bifunctional catalyst has catalytic performance of solid alkali during catalytic hydrogenation, so that insufficient addition of alkali liquor is effectively avoided in the prior art. The bifunctional catalyst is high in catalytic activity and is convenient to recycle and reuse. Post-treatment of synthesizing the benzotriazoles compound is simplified, and the problem of environmental pollution resulting from post-treatment of the alkali liquor is effectively avoided. The synthetic method is efficient, and is low in cost and easy and simple to operate.

Preparation method of ultraviolet absorbent containing chlorobenzotriazole

The invention relates to a preparation method of an ultraviolet absorbent containing chlorobenzotriazole. Azobenzene, sodium hydroxide and toluene are stirred and mixed, the temperature is controlled to 60-80 DEG C, water and hydrazine are dropwise added at a constant speed, heat preservation reaction is performed after the completion of dropping, hydrochloric acid is added to perform neutralization to reach the pH of 6-7 after completion of hydrazine reduction, washing is performed, and an oil phase, namely nitrogen oxide, is obtained; the nitrogen oxide solution, alkali, a framework nickel catalyst and a catalyst promoter sodium phosphite are put into an autoclave, and hydrogen is led to perform constant-pressure constant-temperature reaction after nitrogen displacement; after reaction is completed, reaction liquid filtration and washing are performed, an organic phase evaporated solvent is obtained, and recrystallization, filtration and drying are conducted on the methanol and toluene mixed solvent to obtain the ultraviolet absorbent containing chlorobenzotriazole. Compared with an existing synthetic method, the preparation method has the advantages of being good in reaction selectivity, inhibiting a dechlorination phenomenon in the hydrogenation process, producing few by-products and the like and meanwhile does not produce wastewater containing zinc and aluminum, subsequent processing is simple, and the 'three wastes' problem produced in the secondary reduction process is solved.

Preparation method of benzotriazole light stabilizer

The invention discloses a preparation method of a benzotriazole ultraviolet light stabilizer. The method comprises the following steps: adding an azo dye intermediate represented by formula I to hydrazine hydrate, carrying out reduction to form an intermediate nitrogen oxide represented by formula II, and reducing the intermediate nitrogen oxide represented by formula II with hydrogen to prepare the benzotriazole ultraviolet light stabilizer represented by formula III, wherein the formula I, the formula II and the formula III are respectively shown in the description, and R in the formulas is C(CH3)3 or CH3. The preparation method allows wastewater generated in the invention to be environmentally-friendly.

Preparation of 2-aryl-2H-benzotriazoles by zinc-mediated reductive cyclization of o-nitrophenylazophenols in aqueous media without the use of organic solvents

Zinc powder-mediated reductive cyclization of o-nitrophenylazophenols in alkaline solution affords the corresponding 2-aryl-2H-benzotriazoles in high yields under mild reaction conditions. No organic solvents are used in the reaction and only minimal amounts in the work-up.

Process for the preparation of benzotriazoles

A process for the preparation of compounds of formula (I): wherein the general symbols are as defined in claim 1, which comprises reacting a compound of formula (V): wherein R1, R2, R3, R4, R5, R6, R7, R8, R9 and R18 are as defined in claim 1, and R18 is especially nitro, chlorine or bromine, with an azide compound of formula (IX): wherein M and n are as defined in claim 1, especially with sodium azide.

Processes for the preparation of benzotriazole UV absorbers

Provided is a process for preparing 2H-benzotriazole UV absorbers containing a perfluoroalkyl moiety at the 5-position of the benzo ring, for example a trifluoromethyl group, which involves diazotizing the perfluoroalkyl substituted o-nitroaniline using concentrated sulfuric acid plus sodium nitrite or nitrosylsulfuric acid to form the corresponding monoazobenzene intermediate via the diazonium salt intermediate which is reduced to the corresponding 5-perfluoroalkyl substituted 2H-benzotriazole UV absorber compound by conventional reduction means. Also provided is a novel one-pot, multiphase reaction for the preparation of 2(2-nitrophenylazo) substituted phenols, which are precursors for 2H-benzotriazole UV absorbers.

2-(2′-hydroxyphenyl)benzotriazoles used as U.V. stabilizers

2-(2′-hydroxyphenyl)benzotriazoles having general formula (I). The above 2-(2′-hydroxyphenyl)benzotriazoles are useful as light stabilizers for organic polymers.