Metharbital

Barbiturate anticonvulsant medication

N03AA30 (WHO)

Legal statusLegal status

CA: Schedule IV
US: Schedule III

Identifiers

IUPAC name

5,5-Diethyl-1-methylpyrimidine-2,4,6(1H,3H,5H)-trione

CAS Number

50-11-3^Y

PubChem CID

4099

IUPHAR/BPS

7230

DrugBank

DB00463^Y

ChemSpider

3957^Y

UNII

02OS7K758T

KEGG

D01382^Y

ChEMBL

ChEMBL450^Y

CompTox Dashboard (EPA)

DTXSID6023280

ECHA InfoCard100.000.011

Chemical and physical dataFormulaC₉H₁₄N₂O₃Molar mass198.222 g·mol⁻¹3D model (JSmol)

Interactive image

SMILES

O=C1N(C(=O)NC(=O)C1(CC)CC)C

InChI

InChI=1S/C9H14N2O3/c1-4-9(5-2)6(12)10-8(14)11(3)7(9)13/h4-5H2,1-3H3,(H,10,12,14)^Y
Key:FWJKNZONDWOGMI-UHFFFAOYSA-N^Y

(verify)

Metharbital was patented in 1905 by Emil Fischer working for Merck.^[2] It was marketed as Gemonil by Abbott Laboratories. It is a barbiturate anticonvulsant, used in the treatment of epilepsy.^[3]^[4] It has similar properties to phenobarbital.

History

1952 Gemonil was introduced by Abbott Laboratories.
1990 Abbott stopped marketing.

Synthesis

Metharbital can be synthesized from 2,2-diethylmalonic acid and O-methylisourea.^[5]^[6]^[2]

References

^ "Metharbital". The Comparative Toxicogenomics Database.
^ ^a ^b US 782742, Fischer E, "Trisubstituted barbituric acids and process of making them.", issued 14 February 1905, assigned to E. Merck
^ Shorvon SR, Fish DR, Perucca E, Dodson WE, eds. (2004). The Treatment of Epilepsy (2nd ed.). Blackwell. ISBN 0-632-06046-8.
^ Resor SR (1991). The Medical Treatment of Epilepsy. Marcel Dekker. ISBN 0-8247-8549-5.
^ Halpern A, Jones JW (June 1949). "The characterization of the trialkylbarbiturates". Journal of the American Pharmaceutical Association. 38 (6): 352–5. doi:10.1002/jps.3030380619. PMID 18151714.
^ Snyder JA, Link KP (1953). "Preparation and Characterization by Alkaline Methanolysis of 5,5-Diethyl-4-(tetraacetyl-β-D-glucosyloxy)-2,6(1,5)-pyrimidinedione". Journal of the American Chemical Society. 75 (8): 1881–1883. doi:10.1021/ja01104a030.

Anticonvulsants (N03)

GABAergics

GABA_AR PAMs	Barbiturates: Barbexaclone Metharbital Methylphenobarbital Pentobarbital Phenobarbital^# Primidone; Carbamates: Cenobamate Felbamate; Benzodiazepines: Clobazam Clonazepam Clorazepate Diazepam^# Lorazepam^# Midazolam Nimetazepam Nitrazepam Temazepam; Others: Bromide (potassium bromide, sodium bromide) Imepitoin Paraldehyde Stiripentol
GABA-T inhibitors	Fatty acids (and related): Valproate Valpromide Valproate pivoxil Vigabatrin
Others	GABAR agonists: Progabide; GAT-1 inhibitors: Tiagabine

Channel
modulators

Sodium blockers	Hydantoins: Ethotoin Fosphenytoin Mephenytoin Phenytoin^#; Ureides: Acetylpheneturide Chlorphenacemide Phenacemide^‡ Pheneturide; Fatty acids: Valproate Valpromide Valproate pivoxil; Carboxamides: Carbamazepine^# Eslicarbazepine acetate Oxcarbazepine; Others: Lacosamide Lamotrigine^# Rufinamide Topiramate Zonisamide
Calcium blockers	Oxazolidinediones: Ethadione Paramethadione Trimethadione; Succinimides: Ethosuximide^# Mesuximide Phensuximide; Gabapentinoids: Gabapentin Pregabalin; Others: Imepitoin Lamotrigine^# Topiramate Zonisamide
Potassium openers	Retigabine

Others

CA inhibitors	Sulfonamides: Acetazolamide Ethoxzolamide Sultiame Topiramate Zonisamide
Others	Albutoin Beclamide Brivaracetam Cannabidiol Carisbamate Etiracetam Fenfluramine Ganaxolone Levetiracetam Perampanel

^#WHO-EM
^‡Withdrawn from market
Clinical trials:
- ^†Phase III
- ^§Never to phase III

v t e GABA_A receptor positive modulators
Alcohols	Brometone Butanol Chloralodol Chlorobutanol (cloretone) Ethanol (alcohol) (alcoholic drink) Ethchlorvynol Isobutanol Isopropanol Menthol Methanol Methylpentynol Pentanol Petrichloral Propanol tert-Butanol (2M2P) tert-Pentanol (2M2B) Tribromoethanol Trichloroethanol Triclofos Trifluoroethanol
Barbiturates	(-)-DMBB Allobarbital Alphenal Amobarbital Aprobarbital Barbexaclone Barbital Benzobarbital Benzylbutylbarbiturate Brallobarbital Brophebarbital Butabarbital/Secbutabarbital Butalbital Buthalital Butobarbital Butallylonal Carbubarb Crotylbarbital Cyclobarbital Cyclopentobarbital Difebarbamate Enallylpropymal Ethallobarbital Eterobarb Febarbamate Heptabarb Heptobarbital Hexethal Hexobarbital Metharbital Methitural Methohexital Methylphenobarbital Narcobarbital Nealbarbital Pentobarbital Phenallymal Phenobarbital Phetharbital Primidone Probarbital Propallylonal Propylbarbital Proxibarbital Reposal Secobarbital Sigmodal Spirobarbital Talbutal Tetrabamate Tetrabarbital Thialbarbital Thiamylal Thiobarbital Thiobutabarbital Thiopental Thiotetrabarbital Valofane Vinbarbital Vinylbital
Benzodiazepines	2-Oxoquazepam 3-Hydroxyphenazepam Adinazolam Alprazolam Arfendazam Avizafone Bentazepam Bretazenil Bromazepam Bromazolam Brotizolam Camazepam Carburazepam Chlordiazepoxide Ciclotizolam Cinazepam Cinolazepam Clazolam Climazolam Clobazam Clonazepam Clonazolam Cloniprazepam Clorazepate Clotiazepam Cloxazolam CP-1414S Cyprazepam Delorazepam Demoxepam Diazepam Diclazepam Dimdazenil Doxefazepam Elfazepam Estazolam Ethyl carfluzepate Ethyl dirazepate Ethyl loflazepate Etizolam FG-8205 Fletazepam Flubromazepam Flubromazolam Fludiazepam Flunitrazepam Flunitrazolam Flurazepam Flutazolam Flutemazepam Flutoprazepam Fosazepam Gidazepam Halazepam Haloxazolam Iclazepam Imidazenil Irazepine Ketazolam Lofendazam Lopirazepam Loprazolam Lorazepam Lormetazepam Meclonazepam Medazepam Menitrazepam Metaclazepam Mexazolam Midazolam Motrazepam N-Desalkylflurazepam Nifoxipam Nimetazepam Nitrazepam Nitrazepate Nitrazolam Nordazepam Nortetrazepam Oxazepam Oxazolam Phenazepam Pinazepam Pivoxazepam Prazepam Premazepam Proflazepam Pyrazolam QH-II-66 Quazepam Reclazepam Remimazolam Rilmazafone Ripazepam Ro48-6791 Ro48-8684 SH-053-R-CH3-2′F Sulazepam Temazepam Tetrazepam Tolufazepam Triazolam Triflubazam Triflunordazepam (Ro5-2904) Tuclazepam Uldazepam Zapizolam Zolazepam Zomebazam
Carbamates	Carisbamate Carisoprodol Clocental Cyclarbamate Difebarbamate Emylcamate Ethinamate Febarbamate Felbamate Hexapropymate Hydroxyphenamate Lorbamate Mebutamate Meprobamate Nisobamate Pentabamate Phenprobamate Procymate Styramate Tetrabamate Tybamate
Flavonoids	6-Methylapigenin Ampelopsin (dihydromyricetin) Apigenin Baicalein Baicalin Catechin EGC EGCG Hispidulin Linarin Luteolin Rc-OMe Skullcap constituents (e.g., baicalin) Wogonin
Imidazoles	Etomidate Metomidate Propoxate
Kava constituents	10-Methoxyyangonin 11-Methoxyyangonin 11-Hydroxyyangonin Desmethoxyyangonin 11-Methoxy-12-hydroxydehydrokavain 7,8-Dihydroyangonin Kavain 5-Hydroxykavain 5,6-Dihydroyangonin 7,8-Dihydrokavain 5,6,7,8-Tetrahydroyangonin 5,6-Dehydromethysticin Methysticin 7,8-Dihydromethysticin Yangonin
Monoureides	Acecarbromal Apronal (apronalide) Bromisoval Carbromal Capuride Ectylurea
Neuroactive steroids	Acebrochol Allopregnanolone (brexanolone) Alfadolone Alfaxalone 3α-Androstanediol Androstenol Androsterone Certain anabolic-androgenic steroids Cholesterol DHDOC 3α-DHP 5α-DHP 5β-DHP DHT Etiocholanolone Ganaxolone Hydroxydione Minaxolone ORG-20599 ORG-21465 P1-185 Posovolone Pregnanolone (eltanolone) Progesterone Renanolone SAGE-105 SAGE-324 SAGE-516 SAGE-689 SAGE-872 Testosterone THDOC Zuranolone
Nonbenzodiazepines	Cyclopyrrolones: Eszopiclone Pagoclone Pazinaclone Suproclone Suriclone Zopiclone Imidazopyridines: Alpidem DS-1 Necopidem Saripidem Zolpidem Pyrazolopyrimidines: Divaplon Fasiplon Indiplon Lorediplon Ocinaplon Panadiplon Taniplon Zaleplon Others: Adipiplon CGS-8216 CGS-9896 CGS-13767 CGS-20625 CL-218,872 CP-615,003 CTP-354 ELB-139 GBLD-345 Imepitoin JM-1232 L-838,417 Lirequinil (Ro41-3696) NS-2664 NS-2710 NS-11394 Pipequaline ROD-188 RWJ-51204 SB-205,384 SX-3228 TGSC01AA TP-003 TPA-023 TP-13 U-89843A U-90042 Viqualine Y-23684
Phenols	Fospropofol Propofol Thymol
Piperidinediones	Glutethimide Methyprylon Piperidione Pyrithyldione
Pyrazolopyridines	Cartazolate Etazolate ICI-190,622 Tracazolate
Quinazolinones	Afloqualone Cloroqualone Diproqualone Etaqualone Mebroqualone Mecloqualone Methaqualone Methylmethaqualone Nitromethaqualone SL-164
Volatiles/gases	Acetone Acetophenone Acetylglycinamide chloral hydrate Aliflurane Benzene Butane Butylene Centalun Chloral Chloral betaine Chloral hydrate Chloroform Cryofluorane Desflurane Dichloralphenazone Dichloromethane Diethyl ether Enflurane Ethyl chloride Ethylene Fluroxene Gasoline Halopropane Halothane Isoflurane Kerosine Methoxyflurane Methoxypropane Nitric oxide Nitrogen Nitrous oxide Norflurane Paraldehyde Propane Propylene Roflurane Sevoflurane Synthane Teflurane Toluene Trichloroethane (methyl chloroform) Trichloroethylene Vinyl ether
Others/unsorted	3-Hydroxybutanal α-EMTBL AA-29504 Alogabat Avermectins (e.g., ivermectin) Bromide compounds (e.g., lithium bromide, potassium bromide, sodium bromide) Carbamazepine Chloralose Chlormezanone Clomethiazole Darigabat DEABL Deuterated etifoxine Dihydroergolines (e.g., dihydroergocryptine, dihydroergosine, dihydroergotamine, ergoloid (dihydroergotoxine)) DS2 Efavirenz Etazepine Etifoxine Fenamates (e.g., flufenamic acid, mefenamic acid, niflumic acid, tolfenamic acid) Fluoxetine Flupirtine Hopantenic acid KRM-II-81 Lanthanum Lavender oil Lignans (e.g., 4-O-methylhonokiol, honokiol, magnolol, obovatol) Loreclezole Menthyl isovalerate (validolum) Monastrol Niacin Niacinamide Org 25,435 Phenytoin Propanidid Retigabine (ezogabine) Safranal Seproxetine Stiripentol Sulfonylalkanes (e.g., sulfonmethane (sulfonal), tetronal, trional) Terpenoids (e.g., borneol) Topiramate Valerian constituents (e.g., isovaleric acid, isovaleramide, valerenic acid, valerenol) Unsorted benzodiazepine site positive modulators: α-Pinene MRK-409 (MK-0343) TCS-1105 TCS-1205
See also: Receptor/signaling modulators • GABA receptor modulators • GABA metabolism/transport modulators