Cesium carbonate → 6-Chloro-2-methyl-4-(5-methylisoxazol-3-ylamino)pyridazin-3(2H)-one

Participants

Role	Name	HCID	Charge
Reactant	Cesium carbonate	HCID 10796	—
Reactant	3-Amino-5-methylisoxazole	HCID 66172	—
Reactant	1,1'-(9,9-Dimethyl-9H-xanthene-4,5-diyl)bis(1,1-diphenylphosphine)	HCID 636044	—
Reactant	4-Bromo-6-chloro-2-methyl-2,3-dihydropyridazin-3-one	HCID 59216474	—
Catalyst	Bis(dibenzylideneacetone)palladium	HCID 9811564	—
Solvent	1,4-Dioxane	HCID 31275	—
Product	6-Chloro-2-methyl-4-(5-methylisoxazol-3-ylamino)pyridazin-3(2H)-one	HCID 86684023	44%

Reaction Conditions

Temperature	100 °C

Reaction Steps

A 100-mL single-neck round-bottomed flask equipped with a magnetic stirrer and a reflux condenser was charged with 1,4-dioxane (40 mL), 5-methylisoxazol-3-amine (559 mg, 5.7 mmol), 4-bromo-6-chloro-2-methylpyridazin-3(2H)-one (1.89 g, 8.55 mmol), Pd2(dba)3 (521 mg, 0.57 mmol), XantPhos (329 mg, 0.57 mmol), and cesium carbonate (3.72 g, 11.4 mmol). After three cycles of vacuum/argon flush, the mixture was heated at 100° C. for 3 h. Then the mixture was cooled to 80° C. and filtered. The filtrate was cooled to room temperature. It was then filtered to afford 141a (600 mg, 44%) as a yellow solid. MS-ESI: [M+H]+ 241.0

Provenance & Evidence

DOI	10.6084/m9.figshare.5104873.v1
Patent number	US08754077B2
Source dataset	uspto-grants-2014_06
ORD ID	ord-2a70f2defe5a4befad73c1517ed55481
Source note	uspto-grants-2014_06