3147-75-9

Basic information

• Product Name: Octrizole
• Synonyms: LABOTEST-BB LT00053579;EUSORB 323;2-(2'-HYDROXY-5'-TERT-OCTYLLPHENYL)BENZOTRIAZOLE;2-(2'-HYDROXY-5'-TERT-OCTYL PHENYL) BENZOTRIAZOLE;2-(2-HYDROXY-5-TERT-OCTYLPHENYL)BENZOTRIAZOLE;2-(2H-BENZOTRIAZOL-2-YL)-4-(1,1,3,3-TETRAMETHYLBUTYL)PHENOL;TINUVIN 329;OCTRIZOLE
• CAS NO: 3147-75-9
• Molecular Formula: C₂₀H₂₅N₃O
• Molecular Weight: 323.43
• EINECS: 221-573-5
• Product Categories: Intermediates of Dyes and Pigments;Industrial/Fine Chemicals;Phenoles and thiophenoles
• Mol File: 3147-75-9.mol

Chemical Properties

• Melting Point: 106-108 °C(lit.)
• Boiling Point: 471.8 °C at 760 mmHg
• Flash Point: 239.2 °C
• Appearance: Slightly yellowish powder
• Density: 1.1 g/cm³
• Vapor Pressure: 1.58E-09mmHg at 25°C
• Refractive Index: 1.584
• Storage Temp.: 2-8°C
• Solubility: Chloroform (Slightly), Methanol (Slightly)
• PKA: 8.07±0.45(Predicted)
• Water Solubility: 2μg/L at 20℃
• CAS DataBase Reference: Octrizole(CAS DataBase Reference)
• NIST Chemistry Reference: Octrizole(3147-75-9)
• EPA Substance Registry System: Octrizole(3147-75-9)

Safety Data

• Hazard Codes: Xi
• Statements: 36/37/38
• Safety Statements: 26-37/39
• WGK Germany: 1
• Hazardous Substances Data: 3147-75-9(Hazardous Substances Data)

Usage

Characterization

UV-329 is an ultraviolet light absorber (UVA) of the hydroxyphenyl benzotriazole class, which is used as a light stabilizer for plastics and other organic substrates.

Applications

UV-329 is an effective light stabilizer for a variety of plastics and other organic substrates.

Features/benefits

UV-329 protects polymers from UV radiation, helping to preserve the original appearance and physical integrity of molded articles, films, sheets, and fibers during outdoor weathering.

Product forms

UV-329??? Slightly yellow powder UV-329 FL???? Slightly yellow, rodlike granules

Guidelines for use

The use levels of UV-329 range between 0.1 and 1.0 %, depending on substrate and performance requirements of the final application. The product can be used alone or in combination with other additives such as light stabilizers (hindered amines), antioxidants (hindered phenols, phosphites, thiosynergists, hydroxylamines), and other functional stabilizers and additives. The use of UV-329 in combination with hindered amine light stabilizers is particularly noteworthy in that a synergistic performance is often observed. Performance data of UV-329 alone or in combination with other additives are available in selected substrates.

Handling & Safety

UV-329 exhibits a very low order of oral toxicity and does not present any abnormal problems in its handling or general use. Detailed information on handling and any precautions to be observed in the use of the product(s) described in this leaflet can be found in our relevant health and safety information sheet.

Uses

Different sources of media describe the Uses of 3147-75-9 differently. You can refer to the following data:
1. UV absorber
2. Ultraviolet screen.

Definition

An UV light absorber.

Flammability and Explosibility

Notclassified

InChI:InChI=1/C20H25N3O/c1-19(2,3)13-20(4,5)14-10-11-18(24)17(12-14)23-21-15-8-6-7-9-16(15)22-23/h6-12,24H,13H2,1-5H3

Synthetic route

C20H25N3O2 → Cyasorb UV 5411 (3147-75-9)

Conditions	Yield
In isopropyl alcohol at 80 - 82℃; for 4h;	97.5%

2-(2'-hydroxy-5'-tert-octylphenyl)nitrodiazobenzene (51656-57-6) → Cyasorb UV 5411 (3147-75-9)

Conditions	Yield
With methanol; Aminoiminomethanesulfinic acid; sodium hydroxide In toluene at 50 - 80℃; for 0.5h; Reagent/catalyst; Solvent; Temperature;	96.4%
With sodium hydroxide; zinc In water; Petroleum ether at 50℃; for 5h;

2-(2-Nitro-phenylazo)-4-(1,1,3,3-tetramethyl-butyl)-phenol (51656-57-6) → Cyasorb UV 5411 (3147-75-9)

Conditions	Yield
With sodium hydroxide; thiourea S,S-dioxide In water; isopropyl alcohol for 3h; Heating;	96%

2-nitro-2-hydroxy-5-tert-octyl-azobenzene → Cyasorb UV 5411 (3147-75-9)

Conditions	Yield
	93%

2-nitro-aniline (88-74-4) + tert-octylphenol (140-66-9) → Cyasorb UV 5411 (3147-75-9)

Conditions	Yield
Stage #1: 2-nitro-aniline With sulfuric acid In water for 0.333333h; Stage #2: With sodium nitrite In water at 0℃; for 2.5h; Cooling with ice; Stage #3: tert-octylphenol Further stages;	90.01%
Multi-step reaction with 2 steps 1.1: sodium nitrite; hydrogenchloride / water / -15 - 5 °C 1.2: 2 h / 0 °C 2.1: zinc; sodium hydroxide / water; Petroleum ether / 5 h / 50 °C View Scheme

C20H25N3O2 → Cyasorb UV 5411 (3147-75-9)

Conditions	Yield
With hydrogenchloride In water; toluene at 70℃; for 2h; Concentration; Temperature; Reagent/catalyst;	89.5%
With hydrogenchloride; zinc In toluene Reflux;	88.2%

2-nitro-2'-hydroxy-5'-tert-octylazobenzene + 2-nitro-2'-hydroxy-5'-tert-butylazobenzene (27959-42-8) → Cyasorb UV 5411 (3147-75-9)

Conditions	Yield
	85%
	85%

2-nitro-2'-hydroxy-5'-tert-octylazobenzene + 2-Nitro-2'-hydroxy-3',5'-di-tert-pentyl-azobenzene → Cyasorb UV 5411 (3147-75-9)

Conditions	Yield
	83.7%

2-nitro-2'-hydroxy-5'-tert-octylazobenzene → Cyasorb UV 5411 (3147-75-9)

Conditions	Yield
With dimethyl amine; palladium-carbon In water; toluene	82.9%

2-nitro-2'-hydroxy-5'-tert-octylazobenzene + 9-fluorenone (486-25-9) → Cyasorb UV 5411 (3147-75-9)

Conditions	Yield
With sodium hydroxide; sulfuric acid; paraformaldehyde In methanol; water
With sodium hydroxide; sulfuric acid; paraformaldehyde In methanol; water

2-Chloronitrobenzene (88-73-3) → Cyasorb UV 5411 (3147-75-9)

Conditions	Yield
Multi-step reaction with 5 steps 1: ammonium hydroxide / 150 - 220 °C / 90009 - 150015 Torr 2: sodium nitrite; hydrogenchloride / water / 1 h / 10 °C 3: sodium hydroxide / water; ethanol / 3 h / 10 °C / pH 7.2-7.8 4: sodium hydroxide; formaldehyd / Reflux 5: zinc; hydrogenchloride / toluene / Reflux View Scheme

2-nitro-aniline (88-74-4) → Cyasorb UV 5411 (3147-75-9)

Conditions	Yield
Multi-step reaction with 4 steps 1: sodium nitrite; hydrogenchloride / water / 1 h / 10 °C 2: sodium hydroxide / water; ethanol / 3 h / 10 °C / pH 7.2-7.8 3: sodium hydroxide; formaldehyd / Reflux 4: zinc; hydrogenchloride / toluene / Reflux View Scheme

2-nitrobenzenediazonium chloride (119-66-4) → Cyasorb UV 5411 (3147-75-9)

Conditions	Yield
Multi-step reaction with 3 steps 1: sodium hydroxide / water; ethanol / 3 h / 10 °C / pH 7.2-7.8 2: sodium hydroxide; formaldehyd / Reflux 3: zinc; hydrogenchloride / toluene / Reflux View Scheme

trifluoromethylsulfonic anhydride (358-23-6) + Cyasorb UV 5411 (3147-75-9) → trifluoromethanesulfonic acid 2-benzotriazol-2-yl-4-(1,1,3,3-tetramethylbutyl)phenyl ester (943024-15-5)

Conditions	Yield
With pyridine In dichloromethane at 20 - 30℃;	100%

diethylamine (109-89-7) + Cyasorb UV 5411 (3147-75-9) → 2-(2-hydroxy-3-diethylaminomethyl-5-tert-octylphenyl)-2H-benzotriazole

Conditions	Yield
With paraformaldehyde In butan-1-ol	99%
With paraformaldehyde In butan-1-ol	99%
With paraformaldehyde In butan-1-ol	99%

formaldehyd (50-00-0) + Cyasorb UV 5411 (3147-75-9) → methylene bis-benzotriazolyl tetramethylbutylphenol (103597-45-1)

Conditions	Yield
Stage #1: formaldehyd; Cyasorb UV 5411 With diethylamine In 1,3,5-trimethyl-benzene at 130℃; for 4h; Stage #2: With sodium methylate In 1,3,5-trimethyl-benzene at 160℃; for 5h; Temperature; Solvent; Reagent/catalyst;	96.3%

dibutylamine (111-92-2) + Cyasorb UV 5411 (3147-75-9) → 2-[2-Hydroxy-3-(di-n-butylaminomethyl)-5-tert-octylphenyl]-2H-benzotriazole

Conditions	Yield
With paraformaldehyde	96%

tetrakis(dimethylamido)zirconium (IV) (19756-04-8) + Cyasorb UV 5411 (3147-75-9) → [(2-(2H-benzotriazol-2-yl)-4-(2,4,4-trimethylpentan-2-yl)phenol)2(-H)4Zr]

Conditions	Yield
In hexane at 25℃; for 1h; Inert atmosphere;	95%

Cyasorb UV 5411 (3147-75-9) → 2-(2H-benzo[1,2,3]triazol-2-yl)-6-bromo-4-(2,4,4-trimethylpentan-2-yl)phenol

Conditions	Yield
With bromine In dichloromethane at 20℃; for 8h;	95%
With 1,3-dibromo-5,5-dimethylimidazolidine-2,4-dione In chloroform at 20℃;	91%
With 1,3-dibromo-5,5-dimethylimidazolidine-2,4-dione In chloroform at 20℃;	91%

water (7732-18-5) + trimethylaluminum (75-24-1) + Cyasorb UV 5411 (3147-75-9) → bis[2-(2H-benzotriazol-2-yl-κN)-4-(1,1,3,3-tetramethylbutyl)phenolato-κO]methylaluminum(III) dihydrate

Conditions	Yield
Stage #1: trimethylaluminum; Cyasorb UV 5411 In hexane; toluene at -78 - 20℃; for 72h; Inert atmosphere; Stage #2: water	95%

p-formaldehyde + Cyasorb UV 5411 (3147-75-9) → methylene bis-benzotriazolyl tetramethylbutylphenol (103597-45-1)

Conditions	Yield
Stage #1: p-formaldehyde; Cyasorb UV 5411 With diethylamine In xylene at 95 - 100℃; for 24h; Stage #2: With sodium methylate In methanol at 145 - 150℃; for 10h;	92%

tetra(isopropoxy)hafnium isopropanol (1070655-38-7) + Cyasorb UV 5411 (3147-75-9) → [(2-(2H-benzotriazol-2-yl)-4-(2,4,4-trimethylpentan-2-yl)phenol)4Hf]

Conditions	Yield
In hexane at 30℃; for 12h; Inert atmosphere;	92%

Cyasorb UV 5411 (3147-75-9) + isopropenylbenzene (98-83-9) → 2-[2'-hydroxy-3'-(α,α-dimethylbenzyl)-5'-(1,1,3,3-tetramethylbutyl)phenyl]benzotriazole (73936-91-1)

Conditions	Yield
With methanesulfonic acid at 175 - 180℃; for 6.5h; Temperature; Inert atmosphere;	90.3%

chloroform (67-66-3) + water (7732-18-5) + dimethylaluminum chloride (1184-58-3) + Cyasorb UV 5411 (3147-75-9) → bis[2-(2H-benzotriazol-2-yl-κN)-4-(1,1,3,3-tetramethylbutyl)phenolato-κO]chloroaluminum(III)*H2O*CHCl3

Conditions	Yield
Stage #1: dimethylaluminum chloride; Cyasorb UV 5411 In tetrahydrofuran; hexane at -78 - 20℃; for 72h; Inert atmosphere; Stage #2: chloroform; water	90%

Cyasorb UV 5411 (3147-75-9) → 2-(2-Hydroxyphenyl)-2H-benzotriazole (10096-91-0)

Conditions	Yield
With aluminium trichloride; nitromethane In toluene for 7h; Heating;	88%

nonaethyleneglycol mono(p-toluenesulfonyl) ether (62573-11-9) + Cyasorb UV 5411 (3147-75-9) → nonaethylene glycol mono(2-(benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenyl) ether

Conditions	Yield
Stage #1: Cyasorb UV 5411 With sodium hydride In tetrahydrofuran; mineral oil at 20℃; for 1h; Stage #2: nonaethyleneglycol mono(p-toluenesulfonyl) ether In tetrahydrofuran; mineral oil at 20℃; for 24h;	87%

zirconium(IV) tetraisopropoxide 2-propanol (14717-56-7) + Cyasorb UV 5411 (3147-75-9) → [(2-(2H-benzotriazol-2-yl)-4-(2,4,4-trimethylpentan-2-yl)phenol)2(-H)Zr(OiPr)2]

Conditions	Yield
In hexane at 0℃; for 2h; Inert atmosphere;	85%

bis-(dipropylamino)methane (10333-53-6) + Cyasorb UV 5411 (3147-75-9) → methylene bis-benzotriazolyl tetramethylbutylphenol (103597-45-1)

Conditions	Yield
With tetrabutylammomium bromide; sodium hydroxide In neat (no solvent) at 130℃; under 100 Torr; for 2h; Temperature;	80.9%
With sodium hydroxide at 120 - 160℃; under 100 Torr; for 4h; Time;	70.3%

Cyasorb UV 5411 (3147-75-9) → difluoro-[2-(2H-benzotriazol-2-yl-κN)-4-(1,1,3,3-tetramethylbutyl)-phenolate-κO]-boron (1198179-86-0)

Conditions	Yield
With boron trifluoride diethyl etherate In toluene at -78℃; Inert atmosphere; Reflux;	80%

boron trifluoride diethyl etherate (109-63-7) + Cyasorb UV 5411 (3147-75-9) → difluoro-[2-(2H-benzotriazol-2-yl-κN)-4-(1,1,3,3-tetramethylbutyl)-phenolate-κO]-boron (1198179-86-0)

Conditions	Yield
In toluene benzotriazole-compd. dissolved in dried toluene, cooled to -78°C under N2, B-compd. added dropwise, refluxed for 6 h, cooled; evaporated in vac., crystallized from CHCl3, elem. anal.;	80%

tetra(isopropoxy)hafnium isopropanol (1070655-38-7) + Cyasorb UV 5411 (3147-75-9) → [(2-(2H-benzotriazol-2-yl)-4-(2,4,4-trimethylpentan-2-yl)phenol)2Hf(OiPr)2]

Conditions	Yield
In hexane at 0℃; for 3h; Inert atmosphere;	80%

titanium(IV) isopropylate (546-68-9) + Cyasorb UV 5411 (3147-75-9) → [(μ-2-(2H-benzotriazol-2-yl)-4-(2,4,4-trimethylpentan-2-yl)phenolate)Ti(OiPr)3]2 (1416561-82-4)

Conditions	Yield
In hexane at 20℃; for 18h; Inert atmosphere;	77%

formaldehyd (50-00-0) + diisopropylamine (108-18-9) + Cyasorb UV 5411 (3147-75-9) → 2-(2H-benzotriazol-2-yl)-6-((diisopropylamino)-methyl)-4-(2,4,4-trimethylpentan-2-yl)phenol

Conditions	Yield
With triethylamine for 48h; Mannich Aminomethylation; Inert atmosphere; Reflux;	76%

formaldehyd (50-00-0) + Cyasorb UV 5411 (3147-75-9) + N,N`-dimethylethylenediamine (110-70-3) → C46H62N8O2

Conditions	Yield
In ethanol for 72h; Mannich Aminomethylation; Reflux;	76%
In ethanol Reflux;

Upstream product

• 51656-57-6 2-(2-Nitro-phenylazo)-4-(1,1,3,3-tetramethyl-butyl)-phenol 
• 52184-19-7 2-Nitro-2'-hydroxy-3',5'-di-tert-pentyl-azobenzene 
• 486-25-9 9-fluorenone 
• 27959-42-8 2-nitro-2'-hydroxy-5'-tert-butylazobenzene 
• 88-73-3 2-Chloronitrobenzene 
• 88-74-4 2-nitro-aniline 
• 119-66-4 2-nitrobenzenediazonium chloride 
• 51656-57-6 2-(2'-hydroxy-5'-tert-octylphenyl)nitrodiazobenzene 
• 140-66-9 tert-octylphenol 

Downstream Products

• 10096-91-0 2-(2-Hydroxyphenyl)-2H-benzotriazole 
• 185155-06-0 2,2'-dihydroxy-3-(2H-benzotriazol-2-yl)-3'-(4,6-diphenyl-s-triazin-2-yl)-5-tert-octyl-6'-hexyloxy-diphenylmethane 
• 943024-15-5 trifluoromethanesulfonic acid 2-benzotriazol-2-yl-4-(1,1,3,3-tetramethylbutyl)phenyl ester 
• 103597-45-1 methylene bis-benzotriazolyl tetramethylbutylphenol 
• 1198179-82-6 diphenyl-[2-(2H-benzotriazol-2-yl-κN)-4-(1,1,3,3-tetramethyl-butyl)-phenolate-κO]-boron 
• 893418-20-7 2-(2H-benzotriazol-2-yl)-6-chloromethyl-4-(1,1,3,3-tetramethylbutyl)phenol. 
• 1353001-77-0 (C₈NN)BTP-H 

Relevant articles and documents

ANTI-BLUE LIGHT COMPOUND, PREPARATION METHOD AND APPLICATION THEREOF

Disclosed is a blue light absorbing compound, its preparation method and use. The compound has high stability and is suitable for high temperature processing conditions as well as outdoor application. A method of covalently bonding a blue light absorbing compound with an ultraviolet light absorbing compound for increasing its stability is also provided. The compound is capable of absorbing or blocking ultraviolet light (UVA, UVB) and blue light to protect eyes. But long-wavelength blue light can be absorbed diminishingly, so that the transmitted light has a particularly good visual experience.

Reduction method of substituted phenol coupling compound

The invention relates to a reduction method of a substituted phenol coupling compound, which is characterized in that substituted phenol and nitro diazonium salt are coupled to generate a 2-(2'-hydroxy-5'-tert-octyl) nitro diazonium benzene compound, and the 2-(2'-hydroxy-5'-tert-octyl) nitro diazonium benzene compound is subjected to a reduction reaction with thiourea dioxide in alkali liquor andorganic solvent media. The new reduction method is convenient in process, and the yield is 96.5%.

Novel polycyclic compound

The invention provides a novel polycyclic compound as well as a synthesis method and application thereof. The compound of the present invention includes a plurality of carbocyclic and/or heterocyclicstructures having visible or fluorescent light emitting groups and covalently bonded to at least one ultraviolet and/or visible (blue) light absorbing group to provide stability. The compound providedby the invention can be used as a light conversion agent, a dye, a pigment, a fluorescent agent and an ultraviolet light or blue light absorbent, and can be applied to optical films, agricultural films, optical discs (disks), optical lenses, goggles, skin care, cosmetics, illumination, coatings, adhesives, light stabilizers, panels and other products.

Preparation method of benzotriazol ultraviolet absorbent

The invention discloses a preparation method of a benzotriazol ultraviolet absorbent, and belongs to the technical field of organic synthesis. The benzotriazol ultraviolet absorbent is high in selectivity, yield, and atom utilization rate, is capable of reducing environment pollution, and is capable of realizing catalyst circulation utilization. The preparation method comprises following steps: 1,a diazonium salt solution is prepared; 2, p-t-Octylphenol and the diazonium salt solution are subjected to coupling reaction to obtain an azo intermediate (I); 3, the azo intermediate (I) prepared instep 2, 5% Pd/C, and a mixed solvent are subjected to hydrogenation reduction at reaction temperature of 45 to 65 DEG C under hydrogen gas pressure of 0.3 to 1.25MPa for 4 to 10h so as to obtain a nitrogen oxide (II), and UV-329 (III); and 4, column chromatography separation purification is carried out so as to obtain UV-329 (III).

Preparation method of ultraviolet absorbent UV - 329 (by machine translation)

The invention provides a preparation method, UV - 329, of an ultraviolet absorber. The method comprises the following steps: performing ammonification, diazotization, coupling, one-step reduction, two-step reduction reaction and post-treatment to prepare 2 - (2 '- hydroxyl -5' - t-octylphenyl) benzotriazole product by o-nitrochlorobenzene. To the method, by ammonia water with a concentration 10%~25%, o-nitrochlorobenzene is subjected to diazotization reaction with nitrite to generate a diazonium salt, the diazotization reaction does not need to be carried out in a strong acid medium, and byproduct ammonia water of the product in the company is comprehensively utilized. The reduction closed-loop process of the intermediate azo product adopts 2-step reduction method, the strong reducing agent is prevented from directly reducing the azo double bond to the amine, impurity generation, product purity, and yield. (by machine translation)

Method to prepare benzotriazole ultraviolet-absorbing agent via catalytic hydrogen process

The invention relates to a method to prepare a benzotriazole ultraviolet-absorbing agent via a catalytic hydrogen transfer process. The method includes: before hydrogen transfer reaction, refining thereaction material an azobenzene compound, fully removing impurities that disturb the hydrogen transfer reaction to obtain purity of 99% and above, and performing hydrogen transfer reaction. The refining of the material ensures smoothness for the subsequent hydrogen transfer reaction, and the benzotriazole ultraviolet-absorbing agent of high yield and high purity can be obtained; in addition, themethod has significantly reduced usage of quinone catalysts, is green and low in cost and is suitable for industrial production routes.

Preparation method of ultraviolet absorbent UV-329

The invention discloses a preparation method of an ultraviolet absorbent UV-329. The preparation method comprises the following steps that an azo intermediate shown as the formula (I) is reduced into an oxynitride shown as the formula (II) by a reducing agent; then, the oxynitride is reduced into a product shown as the formula (III) by a reducing agent; the reducing agent is formed by sintering metal powder and an adsorbent, wherein the formula (I), the formula (II) and the formula (III) are shown as the accompanying drawing. The preparation method has the beneficial effects that the method provided by the invention has the advantages that the consumption of the metal powder is low; the environment pollution is little; the operation is convenient and simple; the product yield is high.

METHOD FOR PREPARING 2-(2-HYRDROXYPHENYL)-2H-BENZOTRIAZOLE

This invention provides a method for preparing 2-(2-hydroxyphenyl)-2H-benzotriazole of formula (I) below, consisting of steps of a) performing a first reduction in which hydrazine hydrate is added to a compound of formula (II) below with or without a phase transition catalyst in the presence of solvents which include a nonpolar solvent, water, and an alkaline compound, thereby preparing a compound of formula (III) below, and b) performing a second reduction in which water is added to the compound of formula (III) prepared in step a), and then zinc powder and sulfuric acid are added thereto with or without the phase transition catalyst, wherein, X is halogen or hydrogen, R is hydrogen, C1-C12 alkyl, C5-C8 cycloalkyl, phenyl, or phenyl-C1-C4 alkyl; and R' is C1-C12 alkyl, C5-C8 cycloalkyl, phenyl, or phenyl-C1-C4 alkyl

4-Formyl amino-n-methylpiperidine derivatives, the use thereof as stabilisers and organic material stabilised therewith

The present invention relates to 4-formylamino-N-methylpiperidine derivatives of the formula (I) where the variables are as defined in the Description, to a process for preparing these piperidine derivatives, to the use of these piperidine derivatives of the invention, or prepared according to the invention, for stabilizing organic material, in particular for stabilizing plastics or coating materials, and also to the use of these piperidine derivatives of the invention, or prepared according to the invention, as light stabilizers or stabilizers for wood surfaces. The present invention further relates to stabilized organic material which comprises these piperidine derivatives of the invention or prepared according to the invention.

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.