26021-57-8

Basic information

• Product Name: 3,4-dihydro-2H-1,4-benzoxazin-6-ol
• Synonyms: 3,4-DIHYDRO-2H-BENZO[B][1,4]OXAZIN-6-OL;2H-1,4-Benzoxazin-6-ol, 3,4-dihydro-;3,4-Dihydro-2H-benzo[1,4]oxazin-6-ol
• CAS NO: 26021-57-8
• Molecular Formula: C₈H₉NO₂
• Molecular Weight: 151.17
• EINECS: 247-415-5
• Mol File: 26021-57-8.mol
• Article Data: 9

Chemical Properties

• Boiling Point: 334.7°Cat760mmHg
• Flash Point: 156.2°C
• Appearance: /
• Density: 1.241g/cm³
• Vapor Pressure: 6.46E-05mmHg at 25°C
• Refractive Index: 1.582
• Storage Temp.: Keep in dark place,Inert atmosphere,Room temperature
• Solubility: Chloroform (Slightly, Heated, Sonicated), DMSO (Sparingly), Methanol (Slightly)
• PKA: 10.85±0.20(Predicted)
• Water Solubility: 19g/L at 20℃
• CAS DataBase Reference: 3,4-dihydro-2H-1,4-benzoxazin-6-ol(CAS DataBase Reference)
• NIST Chemistry Reference: 3,4-dihydro-2H-1,4-benzoxazin-6-ol(26021-57-8)
• EPA Substance Registry System: 3,4-dihydro-2H-1,4-benzoxazin-6-ol(26021-57-8)

Safety Data

• Hazardous Substances Data: 26021-57-8(Hazardous Substances Data)

Usage

Flammability and Explosibility

Notclassified

InChI:InChI=1/C8H9NO2/c10-6-1-2-8-7(5-6)9-3-4-11-8/h1-2,5,9-10H,3-4H2

Synthetic route

6-hydroxy-3,4-dihydro-2H-1,4-benzoxazin-3-one (53412-38-7) → 3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8)

Conditions	Yield
With borane-THF In tetrahydrofuran at 0 - 20℃;	100%
With borane-THF In tetrahydrofuran at 5 - 20℃; for 24.5h; Inert atmosphere;	95%
With borane-THF In tetrahydrofuran at 0 - 20℃; for 24.5h; Inert atmosphere;	95%

2-((2,5-dimethoxyphenyl)amino)ethane-1-ol (28226-20-2) → 3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8)

Conditions	Yield
With SO42-/ZrO2-MnO2 In water at 110℃; for 4h; Reagent/catalyst;	79.8%
With hydrogen bromide for 2h; cyclocondensation; demethylation; Heating;	76%

6-methoxy-3,4-dihydro-2H-benzo[1,4]oxazine (58960-11-5) → 3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8)

Conditions	Yield
With boron tribromide In dichloromethane at -78 - 20℃; for 2h; Inert atmosphere;	69%

2,5-dimethoxyaniline (102-56-7) + CH2=CHCH2-halide → 3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8)

Conditions	Yield
Multi-step reaction with 2 steps 1: 41 percent / CaCO3 / H2O / 4 h / Heating 2: 76 percent / 62 percent HBr / 2 h / Heating View Scheme

2-amino-4-methoxyphenol (20734-76-3) → 3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8)

Conditions	Yield
Multi-step reaction with 3 steps 1: potassium carbonate / acetonitrile / 10 h / 80 °C / Inert atmosphere 2: lithium aluminium tetrahydride / tetrahydrofuran / 16 h / 0 - 20 °C / Inert atmosphere 3: boron tribromide / dichloromethane / 2 h / -78 - 20 °C / Inert atmosphere View Scheme

6-methoxy-2H-benzo[b][1,4]oxazin-3(4H)-one (5023-12-1) → 3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8)

Conditions	Yield
Multi-step reaction with 2 steps 1: lithium aluminium tetrahydride / tetrahydrofuran / 16 h / 0 - 20 °C / Inert atmosphere 2: boron tribromide / dichloromethane / 2 h / -78 - 20 °C / Inert atmosphere View Scheme

4-methoxy-2-nitrophenol (1568-70-3) → 3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8)

Conditions	Yield
Multi-step reaction with 4 steps 1: ammonium chloride; iron / tetrahydrofuran; methanol; water / 4 h / 80 °C / Inert atmosphere 2: potassium carbonate / acetonitrile / 10 h / 80 °C / Inert atmosphere 3: lithium aluminium tetrahydride / tetrahydrofuran / 16 h / 0 - 20 °C / Inert atmosphere 4: boron tribromide / dichloromethane / 2 h / -78 - 20 °C / Inert atmosphere View Scheme

2-chloro-N-(2',5'-dimethoxyphenyl)acetamide (22158-78-7) → 3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8)

Conditions	Yield
Multi-step reaction with 3 steps 1: boron tribromide / dichloromethane / 20 °C / Inert atmosphere; Cooling with ice 2: sodium hydride / tetrahydrofuran / 20 °C / Inert atmosphere; Cooling with ice 3: borane-THF / tetrahydrofuran / 24.5 h / 5 - 20 °C / Inert atmosphere View Scheme
Multi-step reaction with 3 steps 1: boron tribromide / dichloromethane / 0 - 20 °C / Inert atmosphere 2: sodium hydride / tetrahydrofuran; mineral oil / 0 - 20 °C / Inert atmosphere 3: borane-THF / tetrahydrofuran / 24.5 h / 0 - 20 °C / Inert atmosphere View Scheme

2,5-dimethoxyaniline (102-56-7) → 3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8)

Conditions	Yield
Multi-step reaction with 4 steps 1: triethylamine / acetonitrile / 1 h / Inert atmosphere; Cooling with ice 2: boron tribromide / dichloromethane / 20 °C / Inert atmosphere; Cooling with ice 3: sodium hydride / tetrahydrofuran / 20 °C / Inert atmosphere; Cooling with ice 4: borane-THF / tetrahydrofuran / 24.5 h / 5 - 20 °C / Inert atmosphere View Scheme
Multi-step reaction with 4 steps 1: 1 h / 0 °C / Inert atmosphere 2: boron tribromide / dichloromethane / 0 - 20 °C / Inert atmosphere 3: sodium hydride / tetrahydrofuran; mineral oil / 0 - 20 °C / Inert atmosphere 4: borane-THF / tetrahydrofuran / 24.5 h / 0 - 20 °C / Inert atmosphere View Scheme

2-chloro-N-(2,5-dihydroxyphenyl)acetamide (102580-34-7) → 3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8)

Conditions	Yield
Multi-step reaction with 2 steps 1: sodium hydride / tetrahydrofuran / 20 °C / Inert atmosphere; Cooling with ice 2: borane-THF / tetrahydrofuran / 24.5 h / 5 - 20 °C / Inert atmosphere View Scheme
Multi-step reaction with 2 steps 1: sodium hydride / tetrahydrofuran; mineral oil / 0 - 20 °C / Inert atmosphere 2: borane-THF / tetrahydrofuran / 24.5 h / 0 - 20 °C / Inert atmosphere View Scheme

3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8) + acetic anhydride (108-24-7) → 1-(6-hydroxy-2,3-dihydro-4H-benzo[b][1,4]oxazin-4-yl)ethan-1-one (258524-47-9)

Conditions	Yield
In water at 20℃; Sonication; Heating;	95%
In water at 20 - 50℃; Sonication;	95%
In water for 0.25h; Acetylation; Heating;	65%

3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8) + tert-butyldimethylsilyl chloride (18162-48-6) → 6-(tert-butyl-dimethyl-silanyloxy)-3,4-dihydro-2H-benzo[1,4]oxazine (1446001-82-6)

Conditions	Yield
Stage #1: 3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine With sodium hydride In tetrahydrofuran; mineral oil at 20℃; for 0.333333h; Inert atmosphere; Stage #2: tert-butyldimethylsilyl chloride In tetrahydrofuran; mineral oil for 1h; Time;	94%

3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8) + 4-nitrobenzenediazonium tetrafluoroborate (456-27-9) → (E)-7-((4-nitrophenyl)diazenyl)-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-ol

Conditions	Yield
Stage #1: 3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine With hydrogenchloride In methanol; water for 0.25h; Cooling with ice; Stage #2: 4-nitrobenzenediazonium tetrafluoroborate In methanol; water at 0℃; for 1.25h;	87%
Stage #1: 3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine With hydrogenchloride In methanol; water at 0℃; for 0.25h; Stage #2: 4-nitrobenzenediazonium tetrafluoroborate In methanol; water at 0℃; for 1.25h;	87%

3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8) + propionic acid anhydride (123-62-6) → 1-(6-hydroxy-2,3-dihydro-benzo[1,4]oxazin-4-yl)-propan-1-one (258524-49-1)

Conditions	Yield
In water for 0.25h; Acylation; Heating;	84%

butanoic acid anhydride (106-31-0) + 3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8) → 1-(6-hydroxy-2,3-dihydro-benzo[1,4]oxazin-4-yl)-butan-1-one (258524-51-5)

Conditions	Yield
In water for 0.25h; Acylation; Heating;	79%

3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8) + benzoic acid anhydride (93-97-0) → 4-benzoyl-6-hydroxy-3,4-dihydro-2H-1,4-benzoxazine (258524-53-7)

Conditions	Yield
In ethyl acetate for 1h; Acylation; Heating;	61%

3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8) + Chloroacetic anhydride (541-88-8) → 4-chloroacetyl-6-hydroxy-3,4-dihydro-2H-1,4-benzoxazine (258524-57-1)

Conditions	Yield
In ethyl acetate Acylation; Heating;	57%

3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8) + (E)-7-((4-nitrophenyl)diazenyl)-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-ol → 3,8,9,10-tetrahydro-2H-bis([1,4]oxazino)[2,3-b:3,,2,-i]phenoxazin-4-ium

Conditions	Yield
With perchloric acid In water; isopropyl alcohol at 80℃;	55%
With perchloric acid In water; isopropyl alcohol at 80℃;	55%

3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8) + 5-ethylamino-4-methyl-2-nitrosophenol hydrochloride (63549-31-5) → (Z)-N-(9-methyl-3,4-dihydro-[1,4]oxazino[2,3-b]phenoxazin-8(2H)-ylidene)ethanaminium

Conditions	Yield
With perchloric acid In water; isopropyl alcohol at 80℃;	44%
With perchloric acid In water; isopropyl alcohol at 80℃;	44%

3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8) + ethyl bromide (74-96-4) → 4-ethyl-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-ol (37171-41-8)

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 55℃; for 18h;	38%

N,N-diethyl-3-methoxy-4-nitrosoaniline + 3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8) → N-(3,4-dihydro-[1,4]oxazino[2,3-b]phenoxazin-8(2H)-ylidene)-N-ethylethanaminium

Conditions	Yield
With perchloric acid In water; isopropyl alcohol at 80℃;	32%
With perchloric acid In water; isopropyl alcohol at 80℃;	32%

3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8) → 1-(6-oxiranylmethoxy-2,3-dihydro-benzo[1,4]oxazin-4-yl)-ethanone (1025874-53-6)

Conditions	Yield
Multi-step reaction with 2 steps 1: 65 percent / H2O / 0.25 h / Heating 2: 59 percent / K2CO3 / 3 h / 90 - 95 °C View Scheme

3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8) → 6-(3-isopropylamino-2-hydroxypropoxy)-3,4-dihydro-2H-1,4-benzoxazine

Conditions	Yield
Multi-step reaction with 4 steps 1: 65 percent / H2O / 0.25 h / Heating 2: 59 percent / K2CO3 / 3 h / 90 - 95 °C 3: propan-2-ol / 3 h / Heating 4: aq. KOH / methanol / 3 h / 65 - 70 °C View Scheme

3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8) → 1-(6-oxiranylmethoxy-2,3-dihydro-benzo[1,4]oxazin-4-yl)-propan-1-one (1026846-85-4)

Conditions	Yield
Multi-step reaction with 2 steps 1: 84 percent / H2O / 0.25 h / Heating 2: K2CO3 / 3 h / 90 - 95 °C View Scheme

3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8) → 4-diethylaminoacetyl-6-hydroxy-3,4-dihydro-2H-1,4-benzoxazine (258524-59-3)

Conditions	Yield
Multi-step reaction with 2 steps 1: 57 percent / ethyl acetate / Heating 2: 63 percent / ethanol / 3 h / Heating View Scheme

3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8) → 6-(3-tert-butylamino-2-hydroxypropoxy)-3,4-dihydro-2H-1,4-benzoxazine

Conditions	Yield
Multi-step reaction with 4 steps 1: 65 percent / H2O / 0.25 h / Heating 2: 59 percent / K2CO3 / 3 h / 90 - 95 °C 3: propan-2-ol / 3 h / Heating 4: aq. KOH / methanol / 3 h / 65 - 70 °C View Scheme

3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8) → 1-(6-oxiranylmethoxy-2,3-dihydro-benzo[1,4]oxazin-4-yl)-butan-1-one (1026918-15-9)

Conditions	Yield
Multi-step reaction with 2 steps 1: 79 percent / H2O / 0.25 h / Heating 2: K2CO3 / 3 h / 90 - 95 °C View Scheme

3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8) → 1-[6-(2-hydroxy-3-isopropylamino-propoxy)-2,3-dihydro-benzo[1,4]oxazin-4-yl]-ethanone (258524-70-8)

Conditions	Yield
Multi-step reaction with 3 steps 1: 65 percent / H2O / 0.25 h / Heating 2: 59 percent / K2CO3 / 3 h / 90 - 95 °C 3: propan-2-ol / 3 h / Heating View Scheme

3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8) → (6-oxiranylmethoxy-2,3-dihydro-benzo[1,4]oxazin-4-yl)-phenyl-methanone

Conditions	Yield
Multi-step reaction with 2 steps 1: 61 percent / ethyl acetate / 1 h / Heating 2: K2CO3 / 3 h / 90 - 95 °C View Scheme

3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8) → 4-acetyl-6-(3-tert-butylamino-2-hydroxy-propoxy)-3,4-dihydro-2H-1,4-benzoxazine (258524-75-3)

Conditions	Yield
Multi-step reaction with 3 steps 1: 65 percent / H2O / 0.25 h / Heating 2: 59 percent / K2CO3 / 3 h / 90 - 95 °C 3: propan-2-ol / 3 h / Heating View Scheme

3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8) → 2-diethylamino-1-(6-oxiranylmethoxy-2,3-dihydro-benzo[1,4]oxazin-4-yl)-ethanone (1027928-97-7)

Conditions	Yield
Multi-step reaction with 3 steps 1: 57 percent / ethyl acetate / Heating 2: 63 percent / ethanol / 3 h / Heating 3: K2CO3 / 3 h / 90 - 95 °C View Scheme

3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8) → 1-[6-(2-hydroxy-3-isopropylamino-propoxy)-2,3-dihydro-benzo[1,4]oxazin-4-yl]-propan-1-one

Conditions	Yield
Multi-step reaction with 3 steps 1: 84 percent / H2O / 0.25 h / Heating 2: K2CO3 / 3 h / 90 - 95 °C 3: propan-2-ol / 3 h / Heating View Scheme

3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8) → 1-[6-(3-tert-butylamino-2-hydroxy-propoxy)-2,3-dihydro-benzo[1,4]oxazin-4-yl]-propan-1-one

Conditions	Yield
Multi-step reaction with 3 steps 1: 84 percent / H2O / 0.25 h / Heating 2: K2CO3 / 3 h / 90 - 95 °C 3: propan-2-ol / 3 h / Heating View Scheme

3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8) → 1-[6-(2-hydroxy-3-isopropylamino-propoxy)-2,3-dihydro-benzo[1,4]oxazin-4-yl]-butan-1-one

Conditions	Yield
Multi-step reaction with 3 steps 1: 79 percent / H2O / 0.25 h / Heating 2: K2CO3 / 3 h / 90 - 95 °C 3: propan-2-ol / 3 h / Heating View Scheme

3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8) → 1-[6-(3-tert-butylamino-2-hydroxy-propoxy)-2,3-dihydro-benzo[1,4]oxazin-4-yl]-butan-1-one

Conditions	Yield
Multi-step reaction with 3 steps 1: 79 percent / H2O / 0.25 h / Heating 2: K2CO3 / 3 h / 90 - 95 °C 3: propan-2-ol / 3 h / Heating View Scheme

3,4-dihydro-6-hydroxy-1,4(2H)-benzoxazine (26021-57-8) → [6-(2-hydroxy-3-isopropylamino-propoxy)-2,3-dihydro-benzo[1,4]oxazin-4-yl]-phenyl-methanone

Conditions	Yield
Multi-step reaction with 3 steps 1: 61 percent / ethyl acetate / 1 h / Heating 2: K2CO3 / 3 h / 90 - 95 °C 3: propan-2-ol / 3 h / Heating View Scheme

Upstream product

• 102580-34-7 2-chloro-N-(2,5-dihydroxyphenyl)acetamide 
• 102-56-7 2,5-dimethoxyaniline 
• 22158-78-7 2-chloro-N-(2',5'-dimethoxyphenyl)acetamide 
• 1568-70-3 4-methoxy-2-nitrophenol 
• 58960-11-5 6-methoxy-3,4-dihydro-2H-benzo[1,4]oxazine 
• 5023-12-1 6-methoxy-2H-benzo[b][1,4]oxazin-3(4H)-one 
• 20734-76-3 2-amino-4-methoxyphenol 
• 53412-38-7 6-hydroxy-3,4-dihydro-2H-1,4-benzoxazin-3-one 
• 28226-20-2 2-((2,5-dimethoxyphenyl)amino)ethane-1-ol 

Downstream Products

• 1257406-54-4 2-(4-{2-[bis(2-hydroxyethyl)amino]ethylamino}-1-methylhexa-1,3,5-trienylamino)-5-(2-hydroxyethylamino)[1,4]-benzoquinone 
• 1161138-59-5 2-[5-amino-1-(2-hydroxyethyl)-1H-pyrazol-4-ylamino]-5-(2-hydroxyethyl-amino)[1,4]benzoquinone 
• 258524-53-7 4-benzoyl-6-hydroxy-3,4-dihydro-2H-1,4-benzoxazine 

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