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Central nervous system drugs

Primidone

Also known as Primaclone, Mysoline, Lepimidin

CAS 125-33-7Formula C12H14N2O2Molar mass 218.26 g/molEC 204-737-0
GHS signal word: Danger. Pictograms: Harmful or irritant, Serious health hazard 88 suppliers listed Drug substance
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Primidone chemical structure, C12H14N2O2, CAS 125-33-7
2D chemical structure

Key facts

What buyers check first

All properties
Appearance
Crystals
Melting point
281.5 °C
Solubility
In water, 480 mg/L at 30 °C
HS code
293359
Category
Central nervous system drugs
UN number
UN 3249
Illustrative photo, drums, an IBC tote and sacks in a chemical warehouse in a warehouse
Typical packagingIllustrative packaging image, not the actual product

What is Primidone?

Plain description, key identifiers and synonyms

Primidone is a pyrimidone that is dihydropyrimidine-4,6(1H,5H)-dione substituted by an ethyl and a phenyl group at position 5. It is used as an anticonvulsant for treatment of various types of seizures. It has a role as an anticonvulsant, a xenobiotic and an environmental contaminant.

Identifiers

Registry numbers, names and line notations, tap to copy

IUPAC name
5-ethyl-5-phenyl-1,3-diazinane-4,6-dione
CAS number
125-33-7 CAS number cross-checked
EC number
204-737-0
Molecular formula
C12H14N2O2
UNII
13AFD7670Q
MDL number
MFCD00038662
InChIKey
DQMZLTXERSFNPB-UHFFFAOYSA-N
InChI
InChI=1S/C12H14N2O2/c1-2-12(9-6-4-3-5-7-9)10(15)13-8-14-11(12)16/h3-7H,2,8H2,1H3,(H,13,15)(H,14,16)
SMILES (canonical and isomeric)
CCC1(C(=O)NCNC1=O)C2=CC=CC=C2

Synonyms

  • Primaclone
  • Mysoline
  • Lepimidin
  • 2-Deoxyphenobarbital
  • Lepsiral
  • Liskantin
  • Milepsin
  • Mylepsin
  • Primakton
  • Mysedon
  • Hexadiona
  • Prilepsin
  • Primoline
  • Prysoline
  • Resimatil
  • Majsolin
  • Misolyne
  • Mizolin
  • Neurosyn
  • Primidon
  • Cyral
  • Midone
  • 2-Desoxyphenobarbital
  • Primacone
  • Desoxyphenobarbitone
Show all 39 synonyms
  • 5-ethyl-5-phenyl-1,3-diazinane-4,6-dione
  • Pyrimidone Medi-pets
  • Primidona
  • Primidonum
  • Roe 101
  • 4,6(1H,5H)-Pyrimidinedione, 5-ethyldihydro-5-phenyl-
  • 5-Phenyl-5-ethyl-hexahydropyrimidine-4,6-dione
  • 5-Ethyldihydro-5-phenyl-4,6(1H,5H)-pyrimidinedione
  • 5-Ethyl-5-phenylhexahydropyrimidine-4,6-dione
  • Hexamidine (the antispasmodic)
  • 5-Ethylhexahydro-4,6-dioxo-5-phenylpyrimidine
  • 5-Ethylhexahydro-5-phenylpyrimidine-4,6-dione
  • 5-Aethyl-5-phenyl-hexahydropyrimidin-4,6-dion
  • Myidone

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

Appearance
Crystalsexp.
Odour
Odorlessexp.
Taste
Practically tastelessexp.
Melting point
281.5 °Cexp.
Solubility
In water, 480 mg/L at 30 °Cexp.

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
218.26 g/molcalc.
Exact mass
218.1055 Dacalc.
LogP (octanol/water)
0.54calc.
Topological polar surface area
58.2 Ųcalc.
Hydrogen bond donors
2calc.
Hydrogen bond acceptors
2calc.
Rotatable bonds
2calc.
Heavy atoms
16calc.
Rings
2calc.
Aromatic rings
1calc.
Fraction sp3 carbons
0.33calc.
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, O=C1NCNC(=O)C1c1ccccc1

O=C1NCNC(=O)C1c1ccccc1

2 rings, 14 atoms.

12 other chemicals share this scaffold

Safety and hazards

GHS classification summary, not a safety data sheet

GHS signal word
Danger
GHS07: Harmful or irritant
Harmful or irritant
GHS08: Serious health hazard
Serious health hazard

Hazard statements

  • H302Harmful if swallowed.
  • H351Suspected of causing cancer.
  • H360May damage fertility or the unborn child.
Precautionary statements (9)
  • P203Obtain, read and follow all safety instructions before use.
  • P264Wash skin thoroughly after handling.
  • P270Do not eat, drink or smoke when using this product.
  • P280Wear protective gloves, protective clothing, eye protection and face protection.
  • P301 + P317If swallowed: Get medical help.
  • P318If exposed or concerned, get medical advice.
  • P330Rinse mouth.
  • P405Store locked up.
  • P501Dispose of contents and container in accordance with local regulations.
UN number
UN 3249

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

Primidone suppliers

Sponsored listings first, then the documented ranking: membership, verification, replies, completeness, freshness and ratings

All 88 suppliers
30 of 30 offers

Suppliers marked Unclaimed profile have not claimed their profile yet. They are not verified by CompoundList, their offers are price on request and details may have changed, so please confirm them with the supplier. Company representatives can claim a profile with a business email on the company's own website domain. Our team verifies each claim and sends the result by email.

Where suppliers are based

88 suppliers in 17 countries

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Primidone price

Indicative price range per kg from live supplier offers

No published prices right now

Suppliers quote this chemical on request. Send one free request and compare quotes side by side.

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Uses and applications

What the substance is used for, by industry and function

Anticonvulsants.

Veterinary medication:.

Use classes: Pharmaceuticals, Animal Drugs.

Industries and functions

Pharmacological actions

  • Anticonvulsants
  • GABA Modulators

Roles

  • anticonvulsant
  • central nervous system depressant
  • central nervous system drug
  • environmental contaminant
  • pharmaceutical
  • xenobiotic

Pharmacology

Primidone is an Anti-epileptic Agent. The physiologic effect of primidone is by means of Decreased Central Nervous System Disorganized Electrical Activity.

How it is made

A solution of ethylphenylmalonamide (I) in a large molecular excess of formamide (II) is refluxed for 2 hr. The cyclization may be viewed as being brought about by a Cannizzaro type of disproportionation of II followed by a deammoniation and a dehydration between I and the highly reactive methanolamine resulting from the disproportionation.

Prepared by electrolytic production of phenobarbital or by catalytic desulfuration of the corresponding 2-thiobarbituric acid: Boon et al., United Kingdom patent 666027 (1952 to I.C.I.)...

Primidone is obtained by reductive desulfurization of 2-thiophenobarbital with Raney nickel or zinc and formic acid, or by ring closure of ethylphenylmalonamide with formamide or formic acid.

Regulatory status

Inventories, regulations and trade controls that list this substance

Health and food

  • Active ingredient in FDA approved drug labels

HS code and trade data

Customs classification and reported world trade statistics

Global trade

World import and export statistics for the HS code Primidone is traded under.

HS 2933.59Indicative HS code

Compounds containing a pyrimidine ring (whether or not hydrogenated) or piperazine ring, other

World exports in 2024
$18.4B
+10.5% vs 2023, imports $24.8B
2019 to 2024
Top exporters
  1. Ireland43.6%
  2. Switzerland * partner reported26.3%
  3. China7.9%
Top importers
  1. Slovenia30.3%
  2. United States30.1%
  3. Germany15.3%

* Partner reported figures, a lower bound.

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

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

Frequently asked questions

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

What is Primidone?

Primidone is a pyrimidone that is dihydropyrimidine-4,6(1H,5H)-dione substituted by an ethyl and a phenyl group at position 5. It is used as an anticonvulsant for treatment of various types of seizures. It has a role as an anticonvulsant, a xenobiotic and an environmental contaminant.

What is the CAS number of Primidone?

The CAS registry number of Primidone is 125-33-7.

What is the molecular formula and weight of Primidone?

The molecular formula of Primidone is C12H14N2O2 and its molar mass is 218.26 g/mol.

What is Primidone used for?

Anticonvulsants. Veterinary medication:. Use classes: Pharmaceuticals, Animal Drugs.

Is Primidone hazardous?

Primidone carries the GHS signal word "Danger". Main hazards: harmful if swallowed, suspected of causing cancer, may damage fertility or the unborn child. This summary is not an SDS, always read the supplier safety data sheet.

What is the HS code of Primidone?

Primidone is usually classified under HS code 293359 (Compounds containing a pyrimidine ring (whether or not hydrogenated) or piperazine ring…). This is indicative, confirm it with your customs broker before shipping.

Where can I buy Primidone?

CompoundList lists 88 suppliers of Primidone in United States, China, India, Germany and 13 more. Send one free request to get and compare quotes. Your contact details stay private until you accept a quote.

Where can I buy Primidone in India?

7 suppliers in India list Primidone on CompoundList. Filter the suppliers list by country and send a request to compare prices, grades and delivery times.

What is the price of Primidone?

Suppliers quote Primidone 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 Primidone

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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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