Pyridazine Basic information
Description Heterocyclic compound Synthesis and Structure
Product Name: Pyridazine
Synonyms: 1,2-diazabenzene radical cation;1,2-Diazabenzene;o-diazine;Pyridazin;1,2-DIAZINE;AKOS 92457;ORTHODIAZINE;OIZINE
CAS: 289-80-5
MF: C4H4N2
MW: 80.09
EINECS: 206-025-5
Product Categories: Heterocyclic Building Blocks;Heterocycles;Organoborons;Pyridazine;Building Blocks;Heterocyclic Building Blocks;Pyridazines;Building Blocks;Chemical Synthesis
Mol File: 289-80-5.mol
Pyridazine Structure
Pyridazine Chemical Properties
Melting point  −8 °C(lit.)
Boiling point  208 °C(lit.)
density  1.103 g/mL at 25 °C(lit.)
refractive index  n20/D 1.524(lit.)
Fp  185 °F
storage temp.  Refrigerator
pka 2.24(at 20℃)
form  Liquid
color  Clear yellow-brown
Water Solubility  MISCIBLE
Merck  14,7969
BRN  103906
InChIKey PBMFSQRYOILNGV-UHFFFAOYSA-N
CAS DataBase Reference 289-80-5(CAS DataBase Reference)
NIST Chemistry Reference Pyridazine(289-80-5)
EPA Substance Registry System Pyridazine (289-80-5)
Safety Information
Hazard Codes  Xn
Risk Statements  36/37/38-22
Safety Statements  23-24/25
RIDADR  NA 1993 / PGIII
WGK Germany  3
RTECS  UR5267000
F  8-10
TSCA  Yes
HS Code  29339980
Toxicity LD50 ipr-mus: 2650 mg/kg PBPHAW 1,542,65

Pyridazine Usage And Synthesis
Description Pyridazine, sometimes called 1,2-diazine, is a six-membered ring containing two adjacent nitrogen atoms. Pyridazine is a privileged structure in medicinal chemistry and can be used as an isosteric replacement of phenyl or heteroaromatic rings. Pyridazines can improve the physiochemical properties of drug molecules by increasing their water solubility, participating as hydrogen bond acceptors, and have a high capacity to complex with targets due to their dipole moment. Pyridazine confers bioavailability, especially to the CNS, and can reduce toxicity. Pyridazine is a part of several drug molecules, and the pyradzine pharmacophore has led to a variety of pharmacologically active compounds.
Heterocyclic compound Pyridazine refers to a heterocyclic azine compound containing a nitrogen hexaheterocyclic , it and pyrimidine, pyrazine are isomers of each other , it is insoluble in petroleum ether, soluble in methanol, ethanol and ether, and it can be miscible with water, benzene and dimethyl formamide immiscibility. Pyridazine is a weak base, which can form salts with picric acid, and hydrochloric acid; pyridazine is not prone to nucleophilic and electrophilic aromatic substitution reaction; it is stable to potassium permanganate; sodium or alcohols may be reduced open-chain , and converted to 1,4-diaminobutane. Pyridazine is widely used as pharmaceutical raw materials, such as long-term sulfa SMP which is pyridazine derivative, 4-amino-cinnoline which belongs to antimalarials, blood pressure drug hydralazine, etc. all use pyridazine as raw materials; it can also be used as raw material of pesticides, for the production of herbicides, "herbicide-sensitive", "Milstem", "bromine herbicide-sensitive", "Kusakira," "maleic hydrazide", "Norflurazon", "pyridate "" insecticide "," imputed phosphorus "and so on.
Synthesis and Structure Pyridazines are heterocyclic compounds with an N-N bond in their ring structure. The pyridazine molecule is a π-deficient heteroaromatic compound similar to pyridine. Due to the presence of the π-deficient nitrogen aromatic heterocycles these compounds are more easily soluble in water when compared to other hydrocarbons. The basic aromatic ring system of pyridazine contains two adjacent nitrogen atoms.
The parent heterocycle was first prepared by oxidation of benzocinnoline to the pyridazinetetracarboxylic acid followed by decarboxylation. A better route to this otherwise esoteric compound starts with the maleic hydrazide. These heterocycles are often prepared via condensation of 1,4-diketones or 4-ketoacids with hydrazines.
Pyridazines are effective water oxidation catalysts with high efficiency turnover numbers up to 700.
Chemical Properties Clear yellowish-brown liquid
Safety Profile Moderately toxic by intraperitoneal route. When heated to decomposition it emits toxic vapors of NOx.
Pyridazine Preparation Products And Raw materials
Preparation Products Cefozopran-->Levosimendan-->Pyridat-->Bazinaprine
Raw materials Hydrazine hydrate-->2,5-Dihydro-2,5-dimethoxyfuran