ChemicalBook > CAS DataBase List > Flumazenil

Flumazenil

Product Name
Flumazenil
CAS No.
78755-81-4
Chemical Name
Flumazenil
Synonyms
Romazicon;ethyl 8-fluoro-5-Methyl-6-oxo-5,6-dihydro-4H-benzo[f]iMidazo[1,5-a][1,4]diazepine-3-carboxylate;FMZ;YM-684;Lanexat;Mazicon;Ro 1722;ANEXATE;RO 15-1788;FLUMAZENIL
CBNumber
CB9208108
Molecular Formula
C15H14FN3O3
Formula Weight
303.29
MOL File
78755-81-4.mol
More
Less

Flumazenil Property

Melting point:
201-203°C
Boiling point:
528.0±50.0 °C(Predicted)
Density 
1.39±0.1 g/cm3(Predicted)
storage temp. 
Sealed in dry,2-8°C
solubility 
Soluble in DMSO to 25mM
form 
solid
pka
0.86±0.20(Predicted)
color 
white
Water Solubility 
128 mg/L
Merck 
14,4135
Stability:
Stable for 2 years from date of purchase as supplied. Solutions in DMSO may be stored at -20°C for up to 3 months.
InChI
InChI=1S/C15H14FN3O3/c1-3-22-15(21)13-12-7-18(2)14(20)10-6-9(16)4-5-11(10)19(12)8-17-13/h4-6,8H,3,7H2,1-2H3
InChIKey
OFBIFZUFASYYRE-UHFFFAOYSA-N
SMILES
N12C=NC(C(OCC)=O)=C1CN(C)C(=O)C1=CC(F)=CC=C12
CAS DataBase Reference
78755-81-4(CAS DataBase Reference)
NIST Chemistry Reference
Flumazenil(78755-81-4)
More
Less

Safety

Hazard Codes 
Xi
Risk Statements 
36/37/38
Safety Statements 
26-27-36/37/39
WGK Germany 
2
RTECS 
NI2922170
HS Code 
2933997500
Toxicity
LD50 in mice, rats (mg/kg): 4000, 1360 i.p.; 4300, 6000 orally (Hunkeler)
More
Less

Hazard and Precautionary Statements (GHS)

Symbol(GHS)
Signal word
Warning
Hazard statements

H303May be harmfulif swallowed

Precautionary statements

P270Do not eat, drink or smoke when using this product.

P301+P312IF SWALLOWED: call a POISON CENTER or doctor/physician IF you feel unwell.

P403Store in a well-ventilated place.

More
Less

N-Bromosuccinimide Price

Sigma-Aldrich
Product number
F6300
Product name
Flumazenil
Purity
>99% (HPLC), solid
Packaging
25mg
Price
$413
Updated
2025/07/31
Sigma-Aldrich
Product number
PHR2702
Product name
Flumazenil
Purity
certified reference material, pharmaceutical secondary standard
Packaging
500MG
Price
$744
Updated
2025/07/31
Sigma-Aldrich
Product number
5.05991
Product name
Flumazenil - CAS 78755-81-4 - Calbiochem
Packaging
10mg
Price
$116
Updated
2025/07/31
Sigma-Aldrich
Product number
1273808
Product name
Flumazenil
Purity
United States Pharmacopeia (USP) Reference Standard
Packaging
200mg
Price
$1950
Updated
2025/07/31
TCI Chemical
Product number
F0958
Product name
Flumazenil
Purity
>99.0%(GC)
Packaging
25mg
Price
$91
Updated
2025/07/31
More
Less

Flumazenil Chemical Properties,Usage,Production

Description

Flumazenil is a benzodiazepine antagonist useful as a fast-acting antidote in the treatment of benzodiazepine intoxication, and in reversing the central sedative effects of benzodiazepines during anesthesia.

Chemical Properties

Flumazenil is a white to off-white crystalline compound with an octanol:buffer partition coefficient of 14 to 1 at pH 7.4. It is insoluble in water but slightly soluble in acidic aqueous solutions.

Originator

Hoffmann-La Roche (Switzerland)

Uses

Flumazenil is an imidazodiazepine which selectively blocks the central effects of classic benzodiazepines. It is used as benzodiazepine antagonist sedation reversal drug.

Definition

ChEBI: Flumazenil is an organic heterotricyclic compound that is 5,6-dihydro-4H-imidazo[1,5-a][1,4]benzodiazepine which is substituted at positions 3, 5, 6, and 8 by ethoxycarbonyl, methyl, oxo, and fluoro groups, respectively. It is used as an antidote to benzodiazepine overdose. It has a role as a GABA antagonist and an antidote to benzodiazepine poisoning. It is an ethyl ester, an organofluorine compound and an imidazobenzodiazepine.

Preparation

The Synthesis of Flumazenil

Starting with 4-fluoroaniline (15) the isatin 17 is synthesized via the Sandmeyer synthesis; isatin is then oxidized with peracetic acid to the isatoic anhydride 18. Reaction with sarcosine in DMF leads to the benzodiazepine-2,5-dione 19. This is converted to the iminochloride by reaction with POCI3 . In the key step the imidazoester is built up by reaction with deprotonated ethyl isocyanoacetate [8]. Since ethyl isocyanoacetate is not very stable, an alternative synthesis based on the synthesis of midazolam was developed for large scale-production. Tnthis synthesis diethylmalonate is used. The diester 21 is then transformed to the monoester 22 hy deethoxycarbonylation. Nitrosation and catalytic reduction lead to the amino compound 23. The final carbon atom is introduced by reaction with the orthoester.

brand name

Romazicon (Roche);Anexate.

Therapeutic Function

Benzodiazepine receptor antagonist, Anticonvulsant

Biological Activity

Flumazenil is a GABAA receptor antagonist with non-selective for α 1, α 2, α 3 or α 5 (IC50 = 2 nM in a radioligand binding assay using rat cortical synaptosomes). Flumazenil also acts as a partial agonist of GABAA receptors, decreasing the amplitude of electrically stimulated population spikes in rat hippocampal CA1 pyramidal neurons. It increases the number of entries into the open arms of the elevated plus maze in high-anxiety BALB/c, but not C57BL/6, mice when administered at doses ranging from 0.1 to 1,000 μg/kg. Flumazenil (5 and 10 mg/kg) prevents a reduction in burying behavior induced by the GABAA receptor positive allosteric modulator allopregnanolone in ovariectomized rats when administered at doses of 5 and 10 mg/kg. Formulations containing flumazenil have been used to reverse sedation induced by benzodiazepines and in the treatment of benzodiazepine overdose or withdrawal.

Pharmacokinetics

Flumazenil is a competitive antagonist at the GA BAA benzodiazepine binding site for all other ligands. I t rapidly reverses the CN S and dangerous physiological effects of benzodiazepines following iatrogenic overdose or deliberate self-harm. I t has no effect on benzodiazepine metabolism. Flumazenil is rapidly cleared from plasma and metabolised by the liver and has a very short elimination half-life (<1h). Its duration of action depends on the dose administered and the duration of action of the drug to be antagonised; repeated administration or infusions may be necessary.

Clinical Use

Reversal of sedative effects of benzodiazepines in anaesthetic, intensive care, and diagnostic procedures

Veterinary Drugs and Treatments

Flumazenil may be useful for the reversal of benzodiazepine effects after either therapeutic use or overdoses. Flumazenil may be of benefit in the treatment of encephalopathy in patients with severe hepatic failure.

Metabolism

Flumazenil is extensively metabolised in the liver.
The carboxylic acid metabolite is the main metabolite in plasma (free form) and urine (free form and its glucuronide). This main metabolite showed no benzodiazepine agonist or antagonist activity in pharmacological tests.
Flumazenil is almost completely (99%) eliminated by non-renal routes. Practically no unchanged flumazenil is excreted in the urine, suggesting complete metabolic degradation of the drug. Elimination of radiolabelled drug is essentially complete within 72 hours, with 90-95% of the radioactivity appearing in urine and 5-10% in the faeces.

storage

+4°C (desiccate)

Mode of action

Flumazenil, an imidazobenzodiazepine derivative, antagonizes the actions of benzodiazepines on the central nervous system. Flumazenil competitively inhibits the activity at the benzodiazepine recognition site on the GABA/benzodiazepine receptor complex. In animal experiments the effects of compounds showing no affinity for the benzodiazepine receptor, e.g. barbiturates, ethanol, meprobamate, GABA mimetics, adenosine receptor agonists and other agents were not affected by flumazenil, but those of nonbenzodiazepine agonists of benzodiazepine receptors, such as cyclopyrrolones (e.g. zopiclone) and triazolopyridazines were blocked.

References

[1] HOWARD AN J G. Flumazenil in benzodiazepine overdose[J]. Canadian Medical Association journal, 2016, 6 1: E537-E537. DOI:10.1503/cmaj.160357
[2] ALEXANDER T GALLO  Gary H. Pharmacological uses of flumazenil in benzodiazepine use disorders: a systematic review of limited data.[J]. Journal of Psychopharmacology, 2021, 35 3: 211-220. DOI:10.1177/0269881120981390

Flumazenil Preparation Products And Raw materials

Raw materials

Preparation Products

More
Less

Flumazenil Suppliers

Jinan Million Pharmaceutical Co., Ltd
Tel
0531-68659554 13031714605
Email
3299907431@qq.com
Country
China
ProdList
92
Advantage
58
Wuhan Biocause Pharmaceutical Development Co., Ltd..
Tel
027-84222527, 13774034449
Fax
027-84222392
Email
zhoubo@biocause.net
Country
China
ProdList
9
Advantage
58
Jinan Wald Chemical Co., Ltd.
Tel
0531-88773586 13210588999
Fax
053188773586
Email
304264064@qq.com
Country
China
ProdList
195
Advantage
58
J & K SCIENTIFIC LTD.
Tel
18210857532; 18210857532
Fax
86-10-82849933
Email
jkinfo@jkchemical.com
Country
China
ProdList
96815
Advantage
76
3B Pharmachem (Wuhan) International Co.,Ltd.
Tel
821-50328103-801 18930552037
Fax
86-21-50328109
Email
3bsc@sina.com
Country
China
ProdList
15838
Advantage
69
Chembest Research Laboratories Limited
Tel
+86-21-20908456
Fax
021-58180499
Email
sales@BioChemBest.com
Country
China
ProdList
6003
Advantage
61
Suzhou haiyu Biochem Industrial Co., LTD
Tel
512-68097639 18013585858
Fax
0512-
Email
744942877@qq.com
Country
China
ProdList
915
Advantage
62
Shanghai Hanhong Scientific Co.,Ltd.
Tel
021-54306202 13764082696
Email
info@hanhongsci.com
Country
China
ProdList
42934
Advantage
64
Chemsky(shanghai)International Co.,Ltd.
Tel
021-50135380
Email
shchemsky@sina.com
Country
China
ProdList
32321
Advantage
50
Sinopharm Chemical Reagent Co,Ltd.
Tel
86-21-63210123
Fax
86-21-63290778 86-21-63218885
Email
sj_scrc@sinopharm.com
Country
China
ProdList
9815
Advantage
79
Aemon Chemical
Tel
0086-755-86198205
Email
acinfo@aemonchem.com
Country
China
ProdList
1931
Advantage
57
ZhengZhou HuaWen Chemical Co.Ltd
Tel
0370-2785118 17550508557
Fax
QQ:3470079902
Email
675141927@qq.com
Country
China
ProdList
3199
Advantage
55
Dalian Meilun Biotech Co., Ltd.
Tel
0411-62910999 13889544652
Email
sales@meilune.com
Country
China
ProdList
4747
Advantage
58
ShangHai YuanYe Biotechnology Co., Ltd.
Tel
021-61312847 13636370518
Fax
021-55068248
Email
shyysw007@163.com
Country
China
ProdList
4999
Advantage
60
T&W GROUP
Tel
021-61551611 13296011611
Fax
+86 21-50676805
Email
contact@trustwe.com
Country
China
ProdList
9895
Advantage
58
Shanghai civi chemical technology co.,Ltd
Tel
86-21-34053660
Fax
86-21-34053661
Email
sale@labgogo.com
Country
China
ProdList
9865
Advantage
52
NCE Biomedical Co.,Ltd.
Tel
4000-027-021 |24 +86-13986109188 | +86-15623472865 | +81-08033611988
Fax
+86-27-87599188
Country
China
ProdList
1493
Advantage
55
Shanghai T&W Pharmaceutical Co., Ltd.
Tel
+86 21 61551611
Fax
+86 21 50676805
Country
China
ProdList
9891
Advantage
58
Haoyuan Chemexpress Co., Ltd.
Tel
021-58950125
Fax
(86) 21-58955996
Email
info@chemexpress.com
Country
China
ProdList
7552
Advantage
61
Shanghai Aladdin Bio-Chem Technology Co.,LTD
Tel
400-6206333 13167063860
Fax
021-50323701
Email
anhua.mao@aladdin-e.com
Country
China
ProdList
25003
Advantage
65
China Nobel Chem Co., Limited
Tel
+86(0)21 60484900
Fax
+86(0)21 60484900
Country
China
ProdList
764
Advantage
50
Guangzhou Isun Pharmaceutical Co., Ltd
Tel
020-39119399 18927568969
Fax
020-39119999
Email
isunpharm@qq.com
Country
China
ProdList
4720
Advantage
55
Nanjing Sunlida Biological Technology Co., Ltd.
Tel
025-57798810
Fax
025-57019371
Email
sales@sunlidabio.com
Country
China
ProdList
3239
Advantage
55
TargetMol Chemicals Inc.
Tel
021-021-33632979 15002134094
Fax
021-33632979
Email
marketing@targetmol.com
Country
China
ProdList
7783
Advantage
58
ShangHai Zexin Chemical Technology Co., Ltd.
Tel
021-60136491 15901897992
Fax
021-60136492
Country
China
ProdList
455
Advantage
55
GIHI CHEMICALS CO.,LTD
Tel
0086-571-86217390
Fax
0086-571-86217391
Email
Sales@gihichem.com
Country
China
ProdList
860
Advantage
58
Taizhou Tongxin Bio-Tech Co., Ltd
Tel
0523-86818997 18652728585
Email
sales@allyrise.com
Country
China
ProdList
2966
Advantage
60
Bide Pharmatech Ltd.
Tel
400-164-7117 13681763483
Fax
+86-21-61629029
Email
product02@bidepharm.com
Country
China
ProdList
39966
Advantage
60
ChemStrong Scientific Co.,Ltd
Tel
0755-0755-66853366 13670046396
Fax
0755-28363542
Email
sales@chem-strong.com
Country
China
ProdList
18333
Advantage
56
Chengdu HuaXia Chemical Reagent Co. Ltd
Tel
400-1166-196 13458535857
Fax
QQ:800101999
Email
cdhxsj@163.com
Country
China
ProdList
13350
Advantage
58
Finetech Industry Limited
Tel
027-87465837 19945049750
Fax
027-8777-2287
Email
sales@finetechnology-ind.com
Country
China
ProdList
9637
Advantage
58
Wuhan Dahua Pharmaceutical Co., Ltd.
Tel
027-59262863 13277907145 3091977954
Fax
027-59420980
Country
China
ProdList
4942
Advantage
58
Shanghai YuLue Chemical Co., Ltd.
Tel
021-60345187 13671753212
Fax
021-34702061
Email
lzz841106@aliyun.com
Country
China
ProdList
10263
Advantage
55
Shanghai Macklin Biochemical Co.,Ltd.
Tel
15221275939
Fax
021-50706099
Email
shenlinxing@macklin.cn
Country
China
ProdList
15873
Advantage
55
Hangzhou J&H Chemical Co., Ltd.
Tel
0571-87396432
Fax
0571-87396431
Email
sales@jhechem.com
Country
China
ProdList
14912
Advantage
59
Wuhan Dahua Weiye Pharmaceutical Chemical Co., Ltd.
Tel
027-59420981,18702770802
Fax
027-83322098
Country
China
ProdList
1975
Advantage
50
AdooQ Bioscience CHINA
Tel
025-58849295 18951903616;
Fax
025-68650336
Email
info@adooq.cn
Country
China
ProdList
2990
Advantage
60
LETOPHARM LIMITED
Tel
+86-21-5821 5861
Fax
+86-21-5106 2861
Email
sales@letopharm.com
Country
China
ProdList
2384
Advantage
58
Chizhou Kailong Import and Export Trade Co., Ltd.
Tel
Fax
-
Email
xg01_gj@163.com
Country
China
ProdList
9484
Advantage
50
Sigma-Aldrich
Tel
021-61415566 800-8193336
Email
orderCN@merckgroup.com
Country
China
ProdList
51395
Advantage
80
Watson Biotechnology Co.,Ltd
Tel
027-59207879 1972026995 18140587686
Fax
QQ:1972026995
Email
sales@3600chem.com
Country
China
ProdList
4447
Advantage
55
Shanghaizehan biopharma technology co., Ltd.
Tel
021-61350663 13052117465
Fax
021-61350662
Email
sales@zehanbiopharma.com
Country
China
ProdList
984
Advantage
55
Shanghai Biolang biotechnology Co.,Ltd
Tel
17764003753
Fax
13669031409
Email
2326587775@qq.com
Country
China
ProdList
188
Advantage
55
Shanghai Biolang biotechnology Co.,Ltd
Tel
17764003753
Fax
13669031409
Email
2326587775@qq.com
Country
China
ProdList
188
Advantage
55
Wuhan Senwayer Century Chemical Co.,Ltd
Tel
027-86652399 13627115097;
Fax
86-27-59707018
Email
sales@senwayer.com
Country
China
ProdList
266
Advantage
55
Hefei TNJ Chemical Industry Co.,Ltd.
Tel
551-65418679 15837135945
Fax
0551-65418697
Email
info@tnjchem.com
Country
China
ProdList
1889
Advantage
62
Codow Chemical Co.,Ltd.
Tel
18620099427
Fax
+86-20-62619665
Email
amy@howeipharm.com
Country
China
ProdList
6687
Advantage
55
Shanghai Haozhixiang Biotechnology Co., Ltd
Tel
526763801 13301653310
Fax
+86-21-51619052
Email
526763801@qq.com
Country
China
ProdList
9274
Advantage
55
Henan CoreyChem Co., Ltd
Tel
0371-86658258
Fax
0371-60996044
Email
info@coreychem.com
Country
China
ProdList
10453
Advantage
58
Shanghai Xilong Biochemical Technology Co., Ltd.
Tel
021-52907766-8042
Fax
021-52906523
Country
China
ProdList
9941
Advantage
58
More
Less

View Lastest Price from Flumazenil manufacturers

Wuhan JiyunZen Tech Co., Ltd.
Product
Flumazenil 78755-81-4
Price
US $5.00-0.50/KG
Min. Order
0.10000000149011612KG
Purity
99% hplc
Supply Ability
5000kg
Release date
2025-06-20
RongNa Biotechnology Co.,Ltd
Product
Flumazenil 78755-81-4
Price
US $1.00/g
Min. Order
1g
Purity
99%
Supply Ability
100kg
Release date
2024-03-26
Jinan Million Pharmaceutical Co., Ltd
Product
Flumazenil 78755-81-4
Price
US $1.00-0.50/kg
Min. Order
1kg
Purity
99%
Supply Ability
200
Release date
2024-01-12

78755-81-4, FlumazenilRelated Search:


  • ethyl 8-fluoro-5-methyl-6-oxo-5,6-dihydro-4h-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate
  • FLUMAZENIL
  • FluMazenil USP
  • 8-FLUORO-5,6-DIHYDRO-5-METHYL-6-OXO-4H-IMIDAZO[1,5-A][1,4]BENZO-DIAZEPINE-3-CARBOXYLIC ACID ETHYL ESTER
  • 8-FLUORO-5,6-DIHYDRO-5-METHYL-6-OXO-4H-IMIDAZO[1,5-A][1,4]BENZODIAZEPINE-3-CARBOXYLIC ACID ETHYL EST
  • RO 15-1788
  • FLUMAZENIL;RO 15-1788; RO15-1788;
  • Flumazenil、Flumazepil
  • FlumazenilUsDmf
  • FMZ
  • Ethyl 8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-α][1,4]benzodiazepine-3-carboxylate
  • Lanexat
  • Mazicon
  • Rcr-15-1788
  • Romazicon
  • ethyl 8-fluoro-5-Methyl-6-oxo-5,6-dihydro-4H-benzo[f]iMidazo[1,5-a][1,4]diazepine-3-carboxylate
  • FluMenazil
  • Ro 15-1788/000
  • Ro 1722
  • Ro 41-8157
  • FluMazenil API
  • FluMazenil(Ro 15-1788)
  • ethyl 12-fluoro-8-Methyl-9-oxo-2,4,8-triazatricyclo[8.4.0.0^{2,6}]tetradeca-1(14),3,5,10,12-pentaene-5-carboxylate
  • 1-4-Amino-3-chloro-5-(trifluoromethyl)phenyl eth Flumazenil
  • Flumazenil, 99.5%
  • ethyl 8-fluoro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate
  • Flumazenil78755-81-4
  • Ethyl 8-fluoro-5-methyl-5,6-dihydro-6-oxo-4H-imidazo(1,5-a)(1,4)benzodiazepine-3-carboxylate
  • 8-Fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazol[1,5-a][1,4]benzodiazepine-3-carboxylic acid ethyl ester
  • YM-684
  • ANEXATE
  • Flumazepil
  • Flumazenil (200 mg)
  • 8-Fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylic acid, ethyl ester
  • 8-fluoro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylic acid ethyl ester
  • Flumazenil Flumazenil
  • Flumazenil &gt
  • Flumazenil USP/EP/BP
  • Flumazenil (1273808)
  • 3R)-(+)-Tartaric acid
  • Fluorine Masini
  • 4H-Imidazo[1,5-a][1,4]benzodiazepine-3-carboxylic acid, 8-fluoro-5,6-dihydro-5-methyl-6-oxo-, ethyl ester
  • Flumazenil in methanol
  • Flumazenil, Benzodiazepine antagonist
  • Flumazenil, Benzodiazepine antagonist (DMSO solution)
  • Flumazenil, 10 mM in DMSO
  • Flumazenil - Bio-X ?
  • Flumazenib
  • Flumazenil, 1mg/ml in Ethanol
  • 78755-81-4
  • 78755-8104
  • 78775-81-4
  • C15H14FN3O3
  • Other APIs
  • ZEBETA
  • API
  • antagonist
  • Active Pharmaceutical Ingredients