Cytosine

CAS 71-30-7

2(1H)-Pyrimidinone, 6-amino-

Molecular structure of 71-30-7
US productionNot reported
Import value, 2024$7.6B
Top sourceIreland 61%

This chemical is listed as active in US commerce, but no company reported it to EPA’s survey for 2019 or 2023. Sites may have made or imported less than the threshold amount, or none.

Why supply is unknown

Production is reported production, not a complete census of factories. Import value and source-country shares describe a shared customs category, not a separate chemical measurement.

Where It Comes From

Customs basis: HS 293359 · basket

These shares come from HS customs code 293359, which covers 295 tracked chemicals in total. They estimate the category's origin mix, not this chemical specifically.

Source Countries
IE 61%IrelandCH 30%SwitzerlandGB 2%United KingdomCN 2%ChinaIN 1%India

Why It Matters

No EPA sector or FDA product records name a use for this chemical.

Vendor Pricing

$0.03/gA2B Chem LLC
CountryUnited States
Pack$16.00 / 500 g
Purity98%
Vendors10 available

Prices reflect listed pack sizes. Small research packs run far above bulk rates.

Chemical Identity

CAS71-30-7
PubChem CIDNot recorded
DTXSIDDTXSID4044456
FormulaC4H5N3O
Mol. Weight111.104 g/mol
SMILESNC1=CC=NC(=O)N1

Data Sources

Brief citations

Cytosine (CAS 71-30-7) https://chemicalindependence.com/chemical/71-30-7/ EPA TSCA Inventory: CAS 71-30-7. Retrieved 2026-10-04. https://www.epa.gov/tsca-inventory US Census international trade: HS 293359 for CAS 71-30-7. Reporting year: 2024. https://usatrade.census.gov/