CompoundList

Penem

Also known as 2,3-didehydropenam, (5R)-4-thia-1-azabicyclo[3.2.0]hept-2-en-7-one, (R)-4-Thia-1-azabicyclo[3.2.0]hept-2-en-7-one

CAS 83961-74-4Formula C5H5NOSMolar mass 127.17 g/mol
Penem chemical structure, C5H5NOS, CAS 83961-74-4
2D chemical structure

Key facts

What buyers check first

CAS number
83961-74-4
Formula
C5H5NOS
Molar mass
127.17 g/mol
HS code
293499
Category
Heterocyclic building blocks

What is Penem?

Plain description, key identifiers and synonyms

Penem is an organic heterobicyclic compound that consists of (5R)-4-thia-1-azabicyclo[3.2.0]hept-2-ene bearing a 7-keto substituent. The parent of the class of penems. It is functionally related to a penam.

Identifiers

Registry numbers, names and line notations, tap to copy

IUPAC name
(5R)-4-thia-1-azabicyclo[3.2.0]hept-2-en-7-one
CAS number
83961-74-4
Molecular formula
C5H5NOS
InChIKey
HHXMXAQDOUCLDN-RXMQYKEDSA-N
InChI
InChI=1S/C5H5NOS/c7-4-3-5-6(4)1-2-8-5/h1-2,5H,3H2/t5-/m1/s1
Canonical SMILES
O=C1CC2SC=CN12
Isomeric SMILES
C1[C@@H]2N(C1=O)C=CS2

Synonyms

  • 2,3-didehydropenam
  • (5R)-4-thia-1-azabicyclo[3.2.0]hept-2-en-7-one
  • (R)-4-Thia-1-azabicyclo[3.2.0]hept-2-en-7-one
  • Peneme

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
127.17 g/molcalc.
Exact mass
127.0092 Dacalc.
LogP (octanol/water)
0.76calc.
Topological polar surface area
20.31 Ųcalc.
Hydrogen bond donors
0calc.
Hydrogen bond acceptors
2calc.
Rotatable bonds
0calc.
Heavy atoms
8calc.
Rings
2calc.
Aromatic rings
0calc.
Fraction sp3 carbons
0.4calc.
Formal charge
0calc.
Stereocentres
1calc.
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, O=C1CC2SC=CN12

O=C1CC2SC=CN12

2 rings, 8 atoms.

27 other chemicals share this scaffold

Safety and hazards

GHS classification summary, not a safety data sheet

No GHS hazard classification is recorded for this substance yet. That does not mean it is harmless.

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

Penem suppliers

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Penem 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

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 Penem is traded under.

HS 2934.99Indicative HS code

Nucleic acids and their salts, other heterocyclic compounds, not elsewhere classified in heading 2934

World exports in 2024
$26.7B
+15.0% vs 2023, imports $26.3B
2019 to 2024
Top exporters
  1. Ireland26.3%
  2. China15.7%
  3. Singapore10.3%
Top importers
  1. United States24.5%
  2. Germany23.1%
  3. Japan4.5%
Reported customs values in USD, not prices.Full trade data

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

Frequently asked questions

Quick answers about Penem, based on the data on this page

What is Penem?

Penem is an organic heterobicyclic compound that consists of (5R)-4-thia-1-azabicyclo[3.2.0]hept-2-ene bearing a 7-keto substituent. The parent of the class of penems. It is functionally related to a penam.

What is the CAS number of Penem?

The CAS registry number of Penem is 83961-74-4.

What is the molecular formula and weight of Penem?

The molecular formula of Penem is C5H5NOS and its molar mass is 127.17 g/mol.

What is Penem used for?

Known uses and roles of Penem include building blocks in research and laboratory and screening compounds in research and laboratory.

Is Penem hazardous?

No GHS hazard classification for Penem is recorded on CompoundList yet. That does not prove it is safe. Always read the supplier safety data sheet.

What is the HS code of Penem?

Penem is usually classified under HS code 293499 (Nucleic acids and their salts, whether or not chemically defined, other heterocyclic…). This is indicative, confirm it with your customs broker before shipping.

Where can I buy Penem?

Post a free request on CompoundList and suppliers of Penem will send you quotes. Your contact details stay private until you accept a quote.

What is the price of Penem?

Suppliers quote Penem 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 Penem

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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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