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HuagongsheHuagongshe Chemistry Print Report · For research reference only
HRID 1842355Generated: November 2, 2026

Methyl iodide → 3(2H)-Pyridazinone, 4,5-dichloro-2-methyl-

https://huagongshe.com/reaction/1842355

Reaction equation

Participants

RoleNameHCIDCharge
ReactantMethyl iodideHCID 6328—
ReactantPotassium CarbonateHCID 11430—
Reactant4,5-Dichloro-3-hydroxypyridazineHCID 73247—
CatalystTetrabutylammonium BromideHCID 74236—
SolventAcetonitrileHCID 6342—
Product3(2H)-Pyridazinone, 4,5-dichloro-2-methyl-HCID 12046270.7%

Reaction Conditions

Temperature115 °C

Reaction Steps

25 g (151 mmoles) of 4,5-dichloropyridazinone are placed in a stainless steel reactor in the presence of 25.13 g (181 mmoles) K2CO3, 1 g (3.03 mmoles) of tetrabutylammonium bromide and 14.2 mL (227 mmoles) of iodomethane in 150 mL acetonitrile. The reaction medium is agitated for 4 h at 115° C. then filtered. The filtrate is concentrated to dryness then solubilized in AcOEt and washed in acid water (pH 1), then with NaCl-saturated water. After drying over Na2SO4, the organic phases are evaporated and the residue obtained is purified by silica gel flash chromatography (CH2Cl2). 19.1 g of intermediate 3a are thus obtained in the form of a yellow solid (yield 70%). TLC silica gel 60 F 254 Merck, petroleum ether-AcOEt: 70:30, Rf=0.48.

Provenance & Evidence

DOI10.6084/m9.figshare.5104873.v1
Patent numberUS08946225B2
Source datasetuspto-grants-2015_02
ORD IDord-b242191848084af19284d290a2def870
Source noteuspto-grants-2015_02