34523-34-7

Basic information

• Product Name: 4-[1-(hydroxyamino)ethylidene]cyclohexa-2,5-dien-1-one
• Synonyms: 4-[1-(hydroxyamino)ethylidene]cyclohexa-2,5-dien-1-one;1-(4-Hydroxyphenyl)-1-ethanone OxiMe;1-(4-Hydroxyphenyl)ethanone OxiMe;NSC 77904;p-Hydroxyacetophenone OxiMe;Ethanone, 1-(4-hydroxyphenyl)-, oxiMe;ParacetaMol IMpurity G;Acetaminophen Impurity 8
• CAS NO: 34523-34-7
• Molecular Formula: C₈H₉NO₂
• Molecular Weight: 151.16
• Product Categories: Aromatic Hydrazides, Hydrazines, Hydrazones and Oximes;Aromatics;Impurities;Intermediates & Fine Chemicals;Pharmaceuticals
• Mol File: 34523-34-7.mol
• Article Data: 34

Chemical Properties

• Melting Point: 142-144°C
• Boiling Point: 294.8 °C at 760 mmHg
• Flash Point: 132.1 °C
• Appearance: /
• Density: 1.246 g/cm³
• Vapor Pressure: 0.000166mmHg at 25°C
• Refractive Index: 1.591
• Storage Temp.: Refrigerator
• PKA: 9.62±0.30(Predicted)
• CAS DataBase Reference: 4-[1-(hydroxyamino)ethylidene]cyclohexa-2,5-dien-1-one(CAS DataBase Reference)
• NIST Chemistry Reference: 4-[1-(hydroxyamino)ethylidene]cyclohexa-2,5-dien-1-one(34523-34-7)
• EPA Substance Registry System: 4-[1-(hydroxyamino)ethylidene]cyclohexa-2,5-dien-1-one(34523-34-7)

Safety Data

• Hazardous Substances Data: 34523-34-7(Hazardous Substances Data)

Usage

Chemical Properties

White to Off-White Solid

Uses

4’-Hydroxyacetophenone Oxime is an impurity of Acetaminophen (A161220), an analgesic and antipyretic agent used as a pain reliever to treat headache, muscle aches, and arthritis (1,2,3).

InChI:InChI=1/C8H9NO2/c1-6(9-11)7-2-4-8(10)5-3-7/h2-5,9,11H,1H3

Synthetic route

4-Hydroxyacetophenone (99-93-4) → 4-hydroxyacetophenone oxime (34523-34-7)

Conditions	Yield
With hydroxylamine hydrochloride; sodium acetate In ethanol; water Reflux;	100%
With hydroxylamine hydrochloride; sodium acetate In water for 1h; Heating;	98%
With hydroxylamine hydrochloride; sodium acetate In ethanol; water Reflux;	91%

4-Hydroxyacetophenone (99-93-4) → 4-acetaminophenol (103-90-2) + 4-hydroxyacetophenone oxime (34523-34-7)

Conditions	Yield
With hydroxylamine hydrochloride In acetonitrile at 70℃; for 15h;	A 90% B 8%
With hydroxylamine hydrochloride at 70 - 110℃; Solvent; chemoselective reaction;

4-Hydroxyacetophenone (99-93-4) → N-Methyl 4-hydroxy benzamide (27642-27-9) + 4-acetaminophenol (103-90-2) + 4-hydroxyacetophenone oxime (34523-34-7)

Conditions	Yield
With hydroxylamine sulfate at 80℃; for 2.5h;	A 15% B 85% C n/a
With hydroxylamine sulfate at 80℃; for 2.5h;	A 15% B 83% C n/a

N-Methyl 4-hydroxy benzamide (27642-27-9) → 4-hydroxyacetophenone oxime (34523-34-7)

Conditions	Yield
With hydrogenchloride; acetic acid In water at 75℃; for 10h; Retrobeckmann rearrangement;	80%

hydroxylamine phosphate + 4-Hydroxyacetophenone (99-93-4) → 4-hydroxyacetophenone oxime (34523-34-7)

Conditions	Yield
With ammonium hydroxide In water	21.0 g (92.6%)
With ammonium hydroxide In water	21.0 g (92.6%)
With ammonium hydroxide In water	21.0 g (92.6%)

acetophenone (98-86-2) + 4-Hydroxyacetophenone (99-93-4) → 4-hydroxyacetophenone oxime (34523-34-7)

Conditions	Yield
With hydroxylamine hydrochloride In pyridine

4-hydroxyacetophenone oxime (34523-34-7) → 4-acetaminophenol (103-90-2)

Conditions	Yield
With 1,1,1,3',3',3'-hexafluoro-propanol; perfluoropinacol; 2-methoxycarbonylphenylboronic acid In nitromethane at 20℃; for 24h; Beckmann Rearrangement; chemoselective reaction;	99%
With 2,2-dichloro-1,3-dicyclohexylimidazolidine-4,5-dione In acetonitrile at 80℃; for 0.333333h; Inert atmosphere; Schlenk technique; Green chemistry;	98%
With carbon tetrabromide; Eosin Y; N,N-dimethyl-formamide In acetonitrile at 20℃; for 14h; Beckmann Rearrangement; Irradiation; Inert atmosphere; Green chemistry;	96%

4-hydroxyacetophenone oxime (34523-34-7) → 4-Hydroxyacetophenone (99-93-4)

Conditions	Yield
With toluene-4-sulfonic acid at 20℃; for 0.0166667h; neat (no solvent);	96%
With water; dihydrogen peroxide; iodine In acetonitrile at 20℃; for 12h;	92%
With formic acid; silica gel for 0.05h; microwave irradiation;	91%

4-hydroxyacetophenone oxime (34523-34-7) + acetic anhydride (108-24-7) → 4-acetyloxyacetophenone oxime

Conditions	Yield
With m-nitrobenzene boronic acid at 20℃; for 12h;	95%

4-hydroxyacetophenone oxime (34523-34-7) → N-Methyl 4-hydroxy benzamide (27642-27-9)

Conditions	Yield
With boron trifluoride diethyl etherate In diethyl ether at 20℃; for 1h; Beckmann rearrangement;	95%
With trifluoroacetic acid In acetonitrile at 109.84℃; Beckmann Rearrangement; Autoclave;

4-hydroxyacetophenone oxime (34523-34-7) → 4-acetamidophenyl sulfurofluoridate (16704-37-3)

Conditions	Yield
Stage #1: 4-hydroxyacetophenone oxime With fluorosulfonyl fluoride; triethylamine In acetonitrile at 20℃; Beckmann Rearrangement; Stage #2: With hydrogenchloride In water; acetonitrile at 20℃; Beckmann Rearrangement;	94%

4-hydroxyacetophenone oxime (34523-34-7) + dichloromalononitrile (13063-43-9) → C11H9Cl2N3O2

Conditions	Yield
In dichloromethane Ambient temperature;	93%

lithium tetrachloropalladate + 4-hydroxyacetophenone oxime (34523-34-7) → (PdCl(N(OH)C(CH3)C6H3(OH)))2 (419581-64-9)

Conditions	Yield
With sodium acetate In methanol to soln. of Li2PdCl4 in MeOH added soln. of oxime and AcONa in MeOH; soln. stirred for 2-3 ds at room temp.; H2O added; ppt. filtered off; elem. anal.;	92%

4-hydroxyacetophenone oxime (34523-34-7) → 4-(1-hydroxyamino-ethyl)-phenol

Conditions	Yield
With Benzyltriethylammonium borohydride at 20℃; for 0.283333h; solid-phase conditions;	86%

1-undecen-11-ylbromide (7766-50-9) + 4-hydroxyacetophenone oxime (34523-34-7) → 1-[4-(undec-10-enyloxy)phenyl]ethanone oxime

Conditions	Yield
With potassium carbonate In acetone for 24h; Heating;	80%

4-hydroxyacetophenone oxime (34523-34-7) + dimethyl 1-(1-diazo-2-oxopropyl)phosphonate (90965-06-3) → 4-(dimethoxyphosphoryl)-6-hydroxy-1,3-dimethylisoquinoline 2-oxide

Conditions	Yield
With bis[dichloro(pentamethylcyclopentadienyl)iridium(III)]; silver(I) triflimide In methanol at 30℃; for 12h;	80%

4-hydroxyacetophenone oxime (34523-34-7) + di-tert-butyl 2,3-diazabicyclo[2.2.1]hept-5-ene-2,3-dicarboxylate (39203-22-0) → C23H33N3O6

Conditions	Yield
With dichloro(pentamethylcyclopentadienyl)rhodium (III) dimer; silver(I) acetate In methanol at 60℃; for 6h;	78%

lithium tetrachloropalladate + 4-hydroxyacetophenone oxime (34523-34-7) + sodium acetate (127-09-3) → di‐μ‐chlorobis [5‐hydroxy‐2‐[1‐(hydroxyimino‐κN) ethyl] phenyl‐κC] palladium (II) (419581-64-9)

Conditions	Yield
In methanol C8H9NO2 (2 mmol) in MeOH and sodium acetate (2 mmol) added to Li2PdCl4 (2 mmol) in MeOH, stirred at room temp. for 72 h; filtered, pptd. with water added; elem. anal.;	75%

4-hydroxyacetophenone oxime (34523-34-7) → 1-(4-hydroxyphenyl)ethanamine hydrochloride

Conditions	Yield
With ammonia; sodium In methanol at 20℃; Cooling with dry ice;	75%

Lawessons reagent (19172-47-5) + 4-hydroxyacetophenone oxime (34523-34-7) → 4-[5-(4-methoxy-phenyl)-5-thioxo-4,5-dihydro-5λ5-[1,2,5]oxazaphosphol-3-yl]-phenol

Conditions	Yield
With sodium hydroxide; cetyltributylphosphonium bromide In dichloromethane; water at 20℃; Cyclization; elimination;	72%

4-hydroxyacetophenone oxime (34523-34-7) + 4-methylphenylboronic acid (5720-05-8) → C15H15NO2 (1408295-45-3)

Conditions	Yield
With copper diacetate; caesium carbonate In dimethyl sulfoxide at 28℃; for 6h; Chan-Lam Coupling;	70%

4-hydroxyacetophenone oxime (34523-34-7) + phenylboronic acid (98-80-6) → C14H13NO2 (1408295-44-2)

Conditions	Yield
With copper diacetate; caesium carbonate In dimethyl sulfoxide at 28℃; for 24h; Chan-Lam Coupling;	60%

4-hydroxyacetophenone oxime (34523-34-7) + (4-acetoxyphenyl)boronic acid (177490-82-3) → C16H15NO4 (1408295-46-4)

Conditions	Yield
With copper diacetate; caesium carbonate In dimethyl sulfoxide at 28℃; for 30h; Chan-Lam Coupling;	55%

1,3,5-trinitrobenzene (99-35-4) + 4-hydroxyacetophenone oxime (34523-34-7) → 1-(4-hydroxyphenyl)ethanone O-(3,5-dinitrophenyl)oxime

Conditions	Yield
With potassium carbonate In 1-methyl-pyrrolidin-2-one at 50℃; for 6h;	49%

4-hydroxyacetophenone oxime (34523-34-7) → 2,2-dibromo-1-(3,5-dibromo-4-hydroxyphenyl)ethanone

Conditions	Yield
With hydrogen bromide; dihydrogen peroxide In water; acetic acid at 15 - 106℃; for 0.333333h;	40%

4-hydroxyacetophenone oxime (34523-34-7) + acetylene (74-86-2) → Z-1-(2-methylthiovinyl)pyrrole + 1-vinyl-2-(4-vinyloxyphenyl)pyrrole (111492-97-8)

Conditions	Yield
With potassium hydroxide In dimethyl sulfoxide at 100℃; under 7600 Torr; for 3h;	A 0.05% B 27%

4-hydroxyacetophenone oxime (34523-34-7) → 4-hydroxy-3,5-diiodoacetophenone oxime (1202385-73-6) + 4-Hydroxyacetophenone (99-93-4)

Conditions	Yield
With water; dihydrogen peroxide; iodine In methanol at 20℃; for 10h;	A 10% B 20%

4-hydroxyacetophenone oxime (34523-34-7) + acetylene (74-86-2) → 2-(4-vinyloxyphenyl)pyrrole (111492-96-7)

Conditions	Yield
With potassium hydroxide In dimethyl sulfoxide at 100℃; for 5h;	2%

4-hydroxyacetophenone oxime (34523-34-7) → 4-acetaminophenol (103-90-2) + 4-Hydroxyacetophenone (99-93-4)

Conditions	Yield
With Tonsil In toluene for 3.5h; Heating;	A 92.8 % Chromat. B 5.9 % Chromat.
With trifluoroacetic acid at 79.84℃; for 18h; Beckmann Rearrangement;

4-hydroxyacetophenone oxime (34523-34-7) + sodium amalgam + methanolic acetic acid → α-methyl-p-hydroxybenzylamine (134855-87-1)

Upstream product

• 99-93-4 4-Hydroxyacetophenone 
• 98-86-2 acetophenone 
• 27642-27-9 N-Methyl 4-hydroxy benzamide 

Downstream Products

• 103-90-2 4-acetaminophenol 
• 99-93-4 4-Hydroxyacetophenone 
• 111492-97-8 1-vinyl-2-(4-vinyloxyphenyl)pyrrole 
• 111492-96-7 2-(4-vinyloxyphenyl)pyrrole 
• 134855-87-1 α-methyl-p-hydroxybenzylamine 
• 13031-43-1 4-acetyloxyacetophenone 
• 2623-33-8 4-acetoxyacetanilide 
• 419581-64-9 (PdCl(N(OH)C(CH₃)C₆H₃(OH)))2 
• 419581-64-9 di‐μ‐chlorobis [5‐hydroxy‐2‐[1‐(hydroxyimino‐κN) ethyl] phenyl‐κC] palladium (II) 
• 1202385-73-6 4-hydroxy-3,5-diiodoacetophenone oxime 
• 768400-82-4 4-(5-bromopentoxy)acetophenone oxime 
• 2061996-43-6 1-(4-hydroxyphenyl)ethanamine hydrochloride 
• 1335246-82-6 1-(4-hydroxyphenyl)ethanone O-(3-amino-5-nitrophenyl)oxime 
• 1335246-57-5 4-(6-amino-4-nitro-1-benzofuran-2-yl)phenol 

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