1,2,4-Triazolo[4,3-a]pyridin-3(2H)-one supplier

Name
1,2,4-Triazolo[4,3-a]pyridin-3(2H)-one
EINECS 230-191-8
CAS No. 6969-71-7
Article Data15
CAS DataBase
Density 1.511 g/cm³
Solubility
Melting Point 231 °C
Formula C₆H₅N₃O
Boiling Point
Molecular Weight 135.125
Flash Point
Transport Information
Appearance Powder
Safety 26-36
Risk Codes 36/37/38
Molecular Structure
Hazard Symbols R36/37/38:;
Synonyms s-Triazolo[4,3-a]pyridin-3-ol(6CI,7CI,8CI);3-Hydroxytriazolo[4,3-a]pyridine;NSC 68462;
PSA 50.16000
LogP 0.02260

Synthetic route

: N'-(pyridin-2-yl)formic hydrazide

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

Conditions

Conditions	Yield
In N,N-dimethyl-formamide at 140℃; for 24h; Reagent/catalyst; Temperature; Solvent; Schlenk technique; Sealed tube;	81%

: 4930-98-7
pyrid-2-ylhydrazine

: 57-13-6
urea

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

Conditions

Conditions	Yield
In neat (no solvent) for 0.0138889h; Microwave irradiation;	75%
at 200℃; for 2h; Cyclization;	57%
at 130℃; for 3h;	15%
at 120 - 160℃; for 4h; Temperature;

N'-(pyridin-2-yl)formic hydrazide: N'-(pyridin-2-yl)formic hydrazide

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

Conditions

Conditions	Yield
In N,N-dimethyl-formamide at 140℃; for 24h; Reagent/catalyst; Temperature; Solvent; Schlenk technique; Sealed tube;	81%

: 4231-61-2
2-benzyl-[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

Conditions

Conditions	Yield
With trifluorormethanesulfonic acid In toluene at 150℃; for 0.25h; Microwave irradiation;	72%

: 4930-98-7
pyrid-2-ylhydrazine

: 57-13-6
urea

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

Conditions

Conditions	Yield
In neat (no solvent) for 0.0138889h; Microwave irradiation;	75%
at 200℃; for 2h; Cyclization;	57%
at 130℃; for 3h;	15%
at 120 - 160℃; for 4h; Temperature;

: 4231-61-2
2-benzyl-[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

Conditions

Conditions	Yield
With trifluorormethanesulfonic acid In toluene at 150℃; for 0.25h; Microwave irradiation;	72%

: 109-09-1
2-chloropyridine

: 563-41-7
semicarbazide hydrochloride

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

Conditions

Conditions	Yield
With sulfuric acid In 2-ethoxy-ethanol for 24h; Reflux;	51%
With sulfuric acid In 2-ethoxy-ethanol for 0.0333333h; Microwave irradiation;	48%
With sulfuric acid In 2-ethoxy-ethanol; water	35.0 g (59%)

: 109-09-1
2-chloropyridine

: 563-41-7
semicarbazide hydrochloride

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

Conditions

Conditions	Yield
With sulfuric acid In 2-ethoxy-ethanol for 24h; Reflux;	51%
With sulfuric acid In 2-ethoxy-ethanol for 0.0333333h; Microwave irradiation;	48%
With sulfuric acid In 2-ethoxy-ethanol; water	35.0 g (59%)

: 109-89-7
diethylamine

: 51330-53-1
1-acetyl-1,2,4-triazolo<4,3-a>pyridinium-3-olate

A: 685-91-6
diethylacetamide

B: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

Conditions

Conditions	Yield
In tetrahydrofuran at 25℃; Rate constant;

...Expand

: 109-89-7
diethylamine

: 51330-53-1
1-acetyl-1,2,4-triazolo<4,3-a>pyridinium-3-olate

A: 685-91-6
diethylacetamide

B: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

Conditions

Conditions	Yield
In tetrahydrofuran at 25℃; Rate constant;

...Expand

: 51330-53-1
1-acetyl-1,2,4-triazolo<4,3-a>pyridinium-3-olate

A: 64-19-7
acetic acid

B: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

Conditions

Conditions	Yield
With water at 25℃; Rate constant;

: 51330-53-1
1-acetyl-1,2,4-triazolo<4,3-a>pyridinium-3-olate

A: 64-19-7
acetic acid

B: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

Conditions

Conditions	Yield
With water at 25℃; Rate constant;

: 109-04-6
2-bromo-pyridine

<1,3>dioxolan-2-ylidene-malonodinitrile: <1,3>dioxolan-2-ylidene-malonodinitrile

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

Conditions

Conditions	Yield
Multi-step reaction with 2 steps 1: 100 percent / NH2NH2 / 2 h / 100 °C 2: 57 percent / 2 h / 200 °C View Scheme

: 109-04-6
2-bromo-pyridine

<1,3>dioxolan-2-ylidene-malonodinitrile: <1,3>dioxolan-2-ylidene-malonodinitrile

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

Conditions

Conditions	Yield
Multi-step reaction with 2 steps 1: 100 percent / NH2NH2 / 2 h / 100 °C 2: 57 percent / 2 h / 200 °C View Scheme

: 109-09-1
2-chloropyridine

: 4426-72-6, 51433-48-8
hydrazine carboxamide

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

Conditions

Conditions	Yield
With sulfuric acid In 2-ethoxy-ethanol; water

: 109-09-1
2-chloropyridine

: 4426-72-6, 51433-48-8
hydrazine carboxamide

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

Conditions

Conditions	Yield
With sulfuric acid In 2-ethoxy-ethanol; water

: 109-04-6
2-bromo-pyridine

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

Conditions

Conditions	Yield
Multi-step reaction with 2 steps 1: hydrazine hydrate / 1,4-dioxane / Reflux 2: 3 h / 130 °C View Scheme
Multi-step reaction with 2 steps 1: hydrazine / N,N-dimethyl-formamide / 0.03 h / Microwave irradiation 2: neat (no solvent) / 0.01 h / Microwave irradiation View Scheme

: 109-04-6
2-bromo-pyridine

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

Conditions

Conditions	Yield
Multi-step reaction with 2 steps 1: hydrazine hydrate / 1,4-dioxane / Reflux 2: 3 h / 130 °C View Scheme
Multi-step reaction with 2 steps 1: hydrazine / N,N-dimethyl-formamide / 0.03 h / Microwave irradiation 2: neat (no solvent) / 0.01 h / Microwave irradiation View Scheme

: 109-09-1
2-chloropyridine

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

Conditions

Conditions	Yield
Multi-step reaction with 3 steps 1: hydrazine hydrate / ethanol / 12 h / Reflux 2: Triethoxysilane / N,N-dimethyl-formamide / 20 °C 3: N,N-dimethyl-formamide / 24 h / 140 °C / Schlenk technique; Sealed tube View Scheme
Multi-step reaction with 2 steps 1: hydrazine / N,N-dimethyl-formamide / 25 h / Heating; Microwave irradiation 2: neat (no solvent) / 0.01 h / Microwave irradiation View Scheme

: 109-09-1
2-chloropyridine

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

Conditions

Conditions	Yield
Multi-step reaction with 3 steps 1: hydrazine hydrate / ethanol / 12 h / Reflux 2: Triethoxysilane / N,N-dimethyl-formamide / 20 °C 3: N,N-dimethyl-formamide / 24 h / 140 °C / Schlenk technique; Sealed tube View Scheme
Multi-step reaction with 2 steps 1: hydrazine / N,N-dimethyl-formamide / 25 h / Heating; Microwave irradiation 2: neat (no solvent) / 0.01 h / Microwave irradiation View Scheme

: 4930-98-7
pyrid-2-ylhydrazine

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

Conditions

Conditions	Yield
Multi-step reaction with 2 steps 1: Triethoxysilane / N,N-dimethyl-formamide / 20 °C 2: N,N-dimethyl-formamide / 24 h / 140 °C / Schlenk technique; Sealed tube View Scheme

: 4930-98-7
pyrid-2-ylhydrazine

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

Conditions

Conditions	Yield
Multi-step reaction with 2 steps 1: Triethoxysilane / N,N-dimethyl-formamide / 20 °C 2: N,N-dimethyl-formamide / 24 h / 140 °C / Schlenk technique; Sealed tube View Scheme

: 109-04-6
2-bromo-pyridine

: 563-41-7
semicarbazide hydrochloride

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

Conditions

Conditions	Yield
With sulfuric acid In 2-ethoxy-ethanol for 0.0333333h; Microwave irradiation;

: 109-04-6
2-bromo-pyridine

: 563-41-7
semicarbazide hydrochloride

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

Conditions

Conditions	Yield
With sulfuric acid In 2-ethoxy-ethanol for 0.0333333h; Microwave irradiation;

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

: 74-88-4
methyl iodide

: 4231-60-1
2-methyl-2H-[1,2,4]triazolo[4,3-a]pyridin-3-one

Conditions

Conditions	Yield
In acetone at 40℃; Alkylation;	100%

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

: 74-88-4
methyl iodide

2-methyl-2H-[1,2,4]triazolo[4,3-a]pyridin-3-one: 4231-60-1
2-methyl-2H-[1,2,4]triazolo[4,3-a]pyridin-3-one

Conditions

Conditions	Yield
In acetone at 40℃; Alkylation;	100%

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

: 103-80-0
phenylacetyl chloride

2-phenylacetyl-1,2,4-triazolo<4,3-a>pyridin-3(2H)-one: 2-phenylacetyl-1,2,4-triazolo<4,3-a>pyridin-3(2H)-one

Conditions

Conditions	Yield
In chloroform Heating;	96%

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

: 103-80-0
phenylacetyl chloride

: 2-phenylacetyl-1,2,4-triazolo<4,3-a>pyridin-3(2H)-one

Conditions

Conditions	Yield
In chloroform Heating;	96%

: 75-44-5
phosgene

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

: 50993-36-7
2-chloroformyl-1,2,4-triazolo<4,3-a>pyridin-3-(2H)-one

Conditions

Conditions	Yield
In tetrahydrofuran for 2h; Heating;	93%

: 75-44-5
phosgene

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

2-chloroformyl-1,2,4-triazolo<4,3-a>pyridin-3-(2H)-one: 50993-36-7
2-chloroformyl-1,2,4-triazolo<4,3-a>pyridin-3-(2H)-one

Conditions

Conditions	Yield
In tetrahydrofuran for 2h; Heating;	93%

: 75-36-5
acetyl chloride

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

: 27191-52-2
2-acetyl-1,2,4-triazolo<4,3-a>pyridin-3(2H)-one

Conditions

Conditions	Yield
In chloroform for 4h; Heating;	92%

: 75-36-5
acetyl chloride

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

: 27191-52-2
2-acetyl-1,2,4-triazolo<4,3-a>pyridin-3(2H)-one

Conditions

Conditions	Yield
In chloroform for 4h; Heating;	92%

: 109-70-6
1,3-chlorobromopropane

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

: 19666-40-1
2-(3-chloropropyl)-1,2,4-triazolo<4,3-a>pyridin-3-one

Conditions

Conditions	Yield
With tetrabutylammomium bromide; potassium carbonate In acetonitrile for 0.0222222h; Solvent; Microwave irradiation;	92%
With potassium carbonate In acetonitrile for 8h; Heating / reflux;	70%

: 109-70-6
1,3-chlorobromopropane

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

: 19666-40-1
2-(3-chloropropyl)-1,2,4-triazolo<4,3-a>pyridin-3-one

Conditions

Conditions	Yield
With tetrabutylammomium bromide; potassium carbonate In acetonitrile for 0.0222222h; Solvent; Microwave irradiation;	92%
With potassium carbonate In acetonitrile for 8h; Heating / reflux;	70%

: 52605-52-4
1-(3-chloropropyl)-4-(3-chlorophenyl)piperazine hydrochloride

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

: 19794-93-5
trazodone

Conditions

Conditions	Yield
With sodium hydroxide In isopropyl alcohol for 26h; Reagent/catalyst; Inert atmosphere; Reflux;	92%
With tetrabutylammomium bromide; potassium carbonate In acetonitrile for 0.0222222h; Time; Microwave irradiation;	92%

: 52605-52-4
1-(3-chloropropyl)-4-(3-chlorophenyl)piperazine hydrochloride

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

: 19794-93-5
trazodone

Conditions

Conditions	Yield
With sodium hydroxide In isopropyl alcohol for 26h; Reagent/catalyst; Inert atmosphere; Reflux;	92%
With tetrabutylammomium bromide; potassium carbonate In acetonitrile for 0.0222222h; Time; Microwave irradiation;	92%

: 5292-43-3
bromoacetic acid tert-butyl ester

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

tert-butyl 2-{3-oxo-2H,3H-[1,2,4]triazolo[4,3-a]pyridin-2-yl}acetate: tert-butyl 2-{3-oxo-2H,3H-[1,2,4]triazolo[4,3-a]pyridin-2-yl}acetate

Conditions

Conditions	Yield
With potassium carbonate In acetonitrile at 60℃; for 1.5h;	70%

: 5292-43-3
bromoacetic acid tert-butyl ester

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

: tert-butyl 2-{3-oxo-2H,3H-[1,2,4]triazolo[4,3-a]pyridin-2-yl}acetate

Conditions

Conditions	Yield
With potassium carbonate In acetonitrile at 60℃; for 1.5h;	70%

1,1-dideutero-3-[4-(3-chlorophenyl)piperazin-1-yl]propan-1-ol: 1181578-67-5
1,1-dideutero-3-[4-(3-chlorophenyl)piperazin-1-yl]propan-1-ol

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

2-(1,1-dideutero-3-(4-(3-chlorophenyl)piperazin-1-yl)propyl)-[1,2,4]triazolo[4,3-a]pyridin-3(2H)one: 1181577-82-1
2-(1,1-dideutero-3-(4-(3-chlorophenyl)piperazin-1-yl)propyl)-[1,2,4]triazolo[4,3-a]pyridin-3(2H)one

Conditions

Conditions	Yield
With triphenylphosphine; diethylazodicarboxylate In tetrahydrofuran at 0 - 20℃;	69%

: 1181578-67-5
1,1-dideutero-3-[4-(3-chlorophenyl)piperazin-1-yl]propan-1-ol

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

: 1181577-82-1
2-(1,1-dideutero-3-(4-(3-chlorophenyl)piperazin-1-yl)propyl)-[1,2,4]triazolo[4,3-a]pyridin-3(2H)one

Conditions

Conditions	Yield
With triphenylphosphine; diethylazodicarboxylate In tetrahydrofuran at 0 - 20℃;	69%

: 6940-78-9
4-chlorobutyl bromide

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

2-(4-chlorobutyl)-[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one: 2-(4-chlorobutyl)-[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

Conditions

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 20℃; Cooling with ice;	69%

: 6940-78-9
4-chlorobutyl bromide

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

: 2-(4-chlorobutyl)-[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

Conditions

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 20℃; Cooling with ice;	69%

: 142944-48-7
1-(3-bromopropyl)-4-(3-chlorophenyl)-piperazine

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

: 19794-93-5
trazodone

Conditions

Conditions	Yield
Stage #1: 1-(3-bromopropyl)-4-(3-chlorophenyl)-piperazine With sodium hydride In 1,4-dioxane for 1h; Reflux; Stage #2: [1,2,4]triazolo[4,3-a]pyridin-3(2H)-one In 1,4-dioxane for 20h; Reflux;	65%

1-(3-bromopropyl)-4-(3-chlorophenyl)-piperazine: 142944-48-7
1-(3-bromopropyl)-4-(3-chlorophenyl)-piperazine

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

: 19794-93-5
trazodone

Conditions

Conditions	Yield
Stage #1: 1-(3-bromopropyl)-4-(3-chlorophenyl)-piperazine With sodium hydride In 1,4-dioxane for 1h; Reflux; Stage #2: [1,2,4]triazolo[4,3-a]pyridin-3(2H)-one In 1,4-dioxane for 20h; Reflux;	65%

: 100-39-0
benzyl bromide

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

A: 42238-98-2
1-benzyl-[1,2,4]triazolo[4,3-a]pyridinium-3-olate

B: 4231-61-2
2-benzyl-[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

Conditions

Conditions	Yield
With potassium carbonate In 1,4-dioxane at 80℃; for 10h; Alkylation;	A 60% B 32%

...Expand

: 100-39-0
benzyl bromide

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

A: 42238-98-2
1-benzyl-[1,2,4]triazolo[4,3-a]pyridinium-3-olate

B: 4231-61-2
2-benzyl-[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

Conditions

Conditions	Yield
With potassium carbonate In 1,4-dioxane at 80℃; for 10h; Alkylation;	A 60% B 32%

...Expand

: 632-02-0
3-chloropropyl p-toluenesulfonate

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

: 19666-40-1
2-(3-chloropropyl)-1,2,4-triazolo<4,3-a>pyridin-3-one

Conditions

Conditions	Yield
Stage #1: [1,2,4]triazolo[4,3-a]pyridin-3(2H)-one With sodium hydride In DMF (N,N-dimethyl-formamide) for 0.5h; Stage #2: 3-chloropropyl p-toluenesulfonate In DMF (N,N-dimethyl-formamide) at 50℃; for 4h;	58%

: 632-02-0
3-chloropropyl p-toluenesulfonate

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

: 19666-40-1
2-(3-chloropropyl)-1,2,4-triazolo<4,3-a>pyridin-3-one

Conditions

Conditions	Yield
Stage #1: [1,2,4]triazolo[4,3-a]pyridin-3(2H)-one With sodium hydride In DMF (N,N-dimethyl-formamide) for 0.5h; Stage #2: 3-chloropropyl p-toluenesulfonate In DMF (N,N-dimethyl-formamide) at 50℃; for 4h;	58%

: 39149-80-9, 54631-38-8, 98104-35-9, 32821-07-1
tert-butyl 2-bromopropionate

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

tert-butyl 2-{3-oxo-2H,3H-[1,2,4]triazolo[4,3-a]pyridin-2-yl}propanoate: tert-butyl 2-{3-oxo-2H,3H-[1,2,4]triazolo[4,3-a]pyridin-2-yl}propanoate

Conditions

Conditions	Yield
With potassium carbonate In acetonitrile at 60℃; for 20h;	58%

: 39149-80-9, 54631-38-8, 98104-35-9, 32821-07-1
tert-butyl 2-bromopropionate

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

: tert-butyl 2-{3-oxo-2H,3H-[1,2,4]triazolo[4,3-a]pyridin-2-yl}propanoate

Conditions

Conditions	Yield
With potassium carbonate In acetonitrile at 60℃; for 20h;	58%

: 106-93-4
ethylene dibromide

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

: 2-(2-bromoethyl)-[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

Conditions

Conditions	Yield
With sodium hydride In N,N-dimethyl-formamide at 20℃; for 6h;	54.7%

: 106-93-4
ethylene dibromide

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

2-(2-bromoethyl)-[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one: 2-(2-bromoethyl)-[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

Conditions

Conditions	Yield
With sodium hydride In N,N-dimethyl-formamide at 20℃; for 6h;	54.7%

: 501-53-1
benzyl chloroformate

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

: 50739-45-2
1-benzyloxycarbonyl-1,2,4-triazolo<4,3-a>pyridinium-3-olate

Conditions

Conditions	Yield
at 90℃; for 1h;	52%

: 501-53-1
benzyl chloroformate

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

: 50739-45-2
1-benzyloxycarbonyl-1,2,4-triazolo<4,3-a>pyridinium-3-olate

Conditions

Conditions	Yield
at 90℃; for 1h;	52%

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

: (1S,2R,5S)-2-(4'-Chloro-biphenyl-4-ylsulfanyl)-5-methanesulfonyloxymethyl-cyclopentanecarboxylic acid tert-butyl ester

: 2-(4'-chloro-biphenyl-4-ylsulfanyl)-5-(3-oxo-[1,2,4]triazolo[4,3-a]pyridin-2-ylmethyl)-cyclopentanecarboxylic acid tert-butyl ester

Conditions

Conditions	Yield
With 15-crown-5; sodium hydride In N,N-dimethyl-formamide at 40℃; for 12h;	46%

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

: (1S,2R,5S)-2-(4'-Chloro-biphenyl-4-ylsulfanyl)-5-methanesulfonyloxymethyl-cyclopentanecarboxylic acid tert-butyl ester

: 2-(4'-chloro-biphenyl-4-ylsulfanyl)-5-(3-oxo-[1,2,4]triazolo[4,3-a]pyridin-2-ylmethyl)-cyclopentanecarboxylic acid tert-butyl ester

Conditions

Conditions	Yield
With 15-crown-5; sodium hydride In N,N-dimethyl-formamide at 40℃; for 12h;	46%

: 1084812-30-5
C17H16BrF2NO

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

: 1084811-05-1
2-(5-(3,5-difluorophenoxy)-2-methyl-2,3,4,5-tetrahydro-1H-benzo[c]azepin-8-yl)-[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

Conditions

Conditions	Yield
With potassium phosphate; N,N`-dimethylethylenediamine; copper(l) iodide In 1,4-dioxane at 110℃; for 16h; Product distribution / selectivity;	46%

: 64528-94-5
1,3-dibromo-1,1,3,3-d4-propane

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

: 1181578-69-7
2-(1,1,3,3-tetradeutero-3-bromopropyl)-[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

Conditions

Conditions	Yield
With potassium carbonate In acetonitrile at 60℃; for 18h;	31%

C17H16BrF2NO: 1084812-30-5
C17H16BrF2NO

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

: 1084811-05-1
2-(5-(3,5-difluorophenoxy)-2-methyl-2,3,4,5-tetrahydro-1H-benzo[c]azepin-8-yl)-[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

Conditions

Conditions	Yield
With potassium phosphate; N,N`-dimethylethylenediamine; copper(l) iodide In 1,4-dioxane at 110℃; for 16h; Product distribution / selectivity;	46%

: 349097-88-7
3-chloro-1-[4-(3-chlorophenyl)piperazin-1-yl]propan-1-one

: 6969-71-7
[1,2,4]triazolo[4,3-a]pyridin-3(2H)-one

: 53689-32-0
1-(3-chloro-phenyl)-4-[3-(3-oxo-[1,2,4]triazolo[4,3-a]pyridin-2-yl)-propionyl]-piperazine

Conditions

Conditions	Yield
With tetrabutylammomium bromide; potassium hydroxide In toluene at 110℃; for 16h;	30%

1,2,4-Triazolo[4,3-a]pyridin-3(2H)-one Specification

The 1,2,4-Triazolo[4,3-a]pyridin-3(2H)-one is an organic compound with the formula C₆H₅N₃O. The IUPAC name of this chemical is 2H-[1,2,4]triazolo[4,3-a]pyridin-3-one. With the CAS registry number 6969-71-7 and EINECS 230-191-8, it is also named as 3-Hydroxytriazolo[4,3-a]pyridine. The product's categories are APIs & Intermediate; Pyrimidine; Pyridines; Fused Ring Systems. It is pale yellow crystalline powder which is used as pharmaceutical intermediate.

The other characteristics of this product can be summarized as: (1)# of Rule of 5 Violations: 0; (2)ACD/BCF (pH 5.5): 1; (3)ACD/BCF (pH 7.4): 1; (4)ACD/KOC (pH 5.5): 18.995; (5)ACD/KOC (pH 7.4): 14.175; (6)#H bond acceptors: 4; (7)#H bond donors: 1; (8)#Freely Rotating Bonds: 0; (9)Polar Surface Area: 44.7 Å²; (10)Index of Refraction: 1.739; (11)Molar Refractivity: 36.01 cm³; (12)Molar Volume: 89.418 cm³; (13)Polarizability: 14.276×10^-24 cm³; (14)Surface Tension: 66.89 dyne/cm; (15)Density: 1.511 g/cm³; (16)Tautomer Count: 2; (17)Exact Mass: 135.043262; (18)MonoIsotopic Mass: 135.043262; (19)Topological Polar Surface Area: 44.7; (20)Heavy Atom Count: 10; (21)Complexity: 264.

Preparation of 1,2,4-Triazolo[4,3-a]pyridin-3(2H)-one: It can be obtained by 2-hydrazino-pyridine and urea. This reaction is a kind of cyclization at temperature of 200 °C. The reaction time is 2 hours. The yield is 57%.

Uses of 1,2,4-Triazolo[4,3-a]pyridin-3(2H)-one: It can react with carbonochloridic acid ethyl ester to get 1-Ethoxycarbonyl-3-oxy-sym.-triazolo[4,3-a]pyridin. This reaction needs heating. The reaction time is 3 hours and the yield is 71%.

When you are using this chemical, please be cautious about it as the following:
It is irritating to eyes, respiratory system and skin. In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. If you want to contact this product, you must wear suitable protective clothing.

People can use the following data to convert to the molecule structure.
1. SMILES:c1ccn2c(c1)n[nH]c2=O
2. InChI:InChI=1/C6H5N3O/c10-6-8-7-5-3-1-2-4-9(5)6/h1-4H,(H,8,10)
3. InChIKey:LJRXNXBFJXXRNQ-UHFFFAOYAU

Product Name

1,2,4-Triazolo[4,3-a]pyridin-3(2H)-one

Synthetic route

1,2,4-Triazolo[4,3-a]pyridin-3(2H)-one Specification

Related Products

Hot Products