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Impurities and reference standards

Pyridine, nitroso-

Also known as 2-nitrosopyridine, Pyridine, 2-nitroso-, nitrosopyridine

CAS 65291-83-0Formula C5H4N2OMolar mass 108.10 g/molEC 173-935-6
GHS signal word: Danger. Pictograms: Acute toxicity (severe), Harmful or irritant, Serious health hazard
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Pyridine, nitroso- chemical structure, C5H4N2O, CAS 65291-83-0
2D chemical structure

Key facts

What buyers check first

All properties
CAS number
65291-83-0
Formula
C5H4N2O
Molar mass
108.10 g/mol
EC number
173-935-6
HS code
293339
Category
Impurities and reference standards

What is Pyridine, nitroso-?

Plain description, key identifiers and synonyms

Pyridine, nitroso- is a chemical substance with the molecular formula C5H4N2O and a molar mass of 108.10 g/mol. Its CAS registry number is 65291-83-0. The IUPAC name is 2-nitrosopyridine.

Identifiers

Registry numbers, names and line notations, tap to copy

IUPAC name
2-nitrosopyridine
CAS number
65291-83-0 CAS number cross-checkedOther or deprecated CAS: 79917-37-6
EC number
173-935-6
Molecular formula
C5H4N2O
MDL number
MFCD30475002
InChIKey
UJMHYOGYJDQSOH-UHFFFAOYSA-N
InChI
InChI=1S/C5H4N2O/c8-7-5-3-1-2-4-6-5/h1-4H
SMILES (canonical and isomeric)
C1=CC=NC(=C1)N=O

Synonyms

  • 2-nitrosopyridine
  • Pyridine, 2-nitroso-
  • nitrosopyridine
  • 2-nitroso-pyridine
  • Antipyrine Impurity N1

Physical and chemical properties

Measured values and descriptors computed from the structure

Physical and chemical properties

Measured values, check the supplier specification for your grade

No measured properties are recorded for this substance yet. Ask suppliers for a technical data sheet.

Values vary by grade. Ask suppliers for the COA or TDS of the batch you buy.

Computed descriptors

Calculated from the structure, useful for screening and formulation

Molecular weight
108.10 g/molcalc.
Exact mass
108.0324 Dacalc.
LogP (octanol/water)
1.48calc.
Topological polar surface area
42.32 Ųcalc.
Hydrogen bond donors
0calc.
Hydrogen bond acceptors
3calc.
Rotatable bonds
1calc.
Heavy atoms
8calc.
Rings
1calc.
Aromatic rings
1calc.
Fraction sp3 carbons
0calc.
Formal charge
0calc.
Stereocentres
0calc.
Lipinski rule of five
Passes (0 violations)calc.

Calculated for screening. Confirm critical figures with the supplier.

Murcko scaffold

The ring system that remains when every side chain is removed

Murcko scaffold of this chemical, c1ccncc1

c1ccncc1

1 ring, 6 atoms, the Pyridine ring system.

118,162 other chemicals share this scaffold

Safety and hazards

GHS classification summary, not a safety data sheet

GHS signal word
Danger
GHS06: Acute toxicity (severe)
Acute toxicity (severe)
GHS07: Harmful or irritant
Harmful or irritant
GHS08: Serious health hazard
Serious health hazard

Hazard statements

  • H227Combustible liquid.
  • H301Toxic if swallowed.
  • H315Causes skin irritation.
  • H319Causes serious eye irritation.
  • H335May cause respiratory irritation.
  • H351Suspected of causing cancer.
Precautionary statements (24)
  • P203Obtain, read and follow all safety instructions before use.
  • P210Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking.
  • P261Avoid breathing dust, fume, gas, mist, vapours or spray.
  • P264Wash skin thoroughly after handling.
  • P264 + P265Wash skin thoroughly after handling. Do not touch eyes.
  • P270Do not eat, drink or smoke when using this product.
  • P271Use only outdoors or in a well-ventilated area.
  • P280Wear protective gloves, protective clothing, eye protection and face protection.
  • P301 + P316If swallowed: Get emergency medical help immediately.
  • P302 + P352If on skin: Wash with plenty of water.
  • P304 + P340If inhaled: Remove person to fresh air and keep comfortable for breathing.
  • P305 + P351 + P338If in eyes: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
  • P318If exposed or concerned, get medical advice.
  • P319Get medical help if you feel unwell.
  • P321Specific treatment (see supplemental first aid instructions on the label).
  • P330Rinse mouth.
  • P332 + P317If skin irritation occurs: Get medical help.
  • P337 + P317If eye irritation persists: Get medical help.
  • P362 + P364Take off contaminated clothing. And wash it before reuse.
  • P370 + P378In case of fire: Use appropriate media to extinguish.
  • P403Store in a well-ventilated place.
  • P403 + P233Store in a well-ventilated place. Keep container tightly closed.
  • P405Store locked up.
  • P501Dispose of contents and container in accordance with local regulations.

GHS classification summary, not a safety data sheet (SDS). Classifications can differ by supplier, grade and concentration. Always check the supplier's SDS.

Full safety data and first aid

Pyridine, nitroso- suppliers

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Pyridine, nitroso- price

Indicative price range per kg from live supplier offers

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Uses and applications

What the substance is used for, by industry and function

Applications are not documented for this substance yet. Suppliers often describe uses on their product pages, linked in the suppliers list above.

Regulatory status

Inventories, regulations and trade controls that list this substance

No regulatory list memberships are recorded for this substance yet. Always check the rules of the importing and exporting country before trade.

HS code and trade data

Customs classification and reported world trade statistics

Global trade

World import and export statistics for the HS code Pyridine, nitroso- is traded under.

HS 2933.39Indicative HS code

Heterocyclic compounds containing an unfused pyridine ring (whether or not hydrogenated) in the structure…

World exports in 2024
$9.16B
−17.9% vs 2023, imports $10.6B
2019 to 2024
Top exporters
  1. China21.5%
  2. India * partner reported12.3%
  3. Ireland11.6%
Top importers
  1. Germany14.2%
  2. United States12.8%
  3. Brazil10.1%

* Partner reported figures, a lower bound.

Reported customs values in USD, not prices.Full trade data

The HS code shown for Pyridine, nitroso- is indicative (it was assigned by structure rules). Confirm the classification with your customs broker before shipping.

Frequently asked questions

Quick answers about Pyridine, nitroso-, based on the data on this page

What is Pyridine, nitroso-?

Pyridine, nitroso- is a chemical substance with the molecular formula C5H4N2O and a molar mass of 108.10 g/mol. Its CAS registry number is 65291-83-0. The IUPAC name is 2-nitrosopyridine.

What is the CAS number of Pyridine, nitroso-?

The CAS registry number of Pyridine, nitroso- is 65291-83-0. Other or deprecated CAS numbers: 79917-37-6.

What is the molecular formula and weight of Pyridine, nitroso-?

The molecular formula of Pyridine, nitroso- is C5H4N2O and its molar mass is 108.10 g/mol.

Is Pyridine, nitroso- hazardous?

Pyridine, nitroso- carries the GHS signal word "Danger". Main hazards: combustible liquid, toxic if swallowed, causes skin irritation. This summary is not an SDS, always read the supplier safety data sheet.

What is the HS code of Pyridine, nitroso-?

Pyridine, nitroso- is usually classified under HS code 293339 (Compounds containing an unfused pyridine ring (whether or not hydrogenated) in the…). This is indicative, confirm it with your customs broker before shipping.

Where can I buy Pyridine, nitroso-?

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What is the price of Pyridine, nitroso-?

Suppliers quote Pyridine, nitroso- on request because prices depend on grade, purity, quantity and destination. A free request on CompoundList gets you several quotes to compare.

Guides for buyers

Practical guides that help when you source, ship or handle Pyridine, nitroso-

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Data last updated 7 Oct 2026. Details may have changed, please confirm them with the supplier. Report an error on this page
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