title: Facile synthesis of 6-aryl 5-N-substituted pyridazinones: microwave-assisted Suzuki-Miyaura cross coupling of 6-chloropyridazinones.
abstract: A facile synthesis of 5-dialkylamino-6-aryl-(2H)-pyridazin-3-one from 5,6-dichloropyridazinone was carried out by using a palladium-catalyzed Suzuki-Miyaura cross coupling of 6-chloro-5-dialkylaminopyridazinone 1 with various arylboronic acids (3 equiv) as the key transformation. The Suzuki-Miyaura cross-coupling reaction proceeded smoothly under microwave irradiation at 135-140 degrees C for 30 min with 5 mol % of Pd catalyst in moderate to good isolated yields. The use of a CombiPhos Pd6 mixture catalyst system and a single Pd-SPhos catalyst system was evaluated.
authors.affiliation: GlaxoSmithKline Pharmaceuticals, 1250 South Collegeville Rd, Collegeville, Pennsylvania 19426, USA. ping_2_cao@gsk.com
authors.forename: Ping
authors.initials: P
authors.lastname: Cao
authors.forename: Junya
authors.initials: J
authors.lastname: Qu
authors.forename: George
authors.initials: G
authors.lastname: Burton
authors.forename: Ralph A
authors.initials: RA
authors.lastname: Rivero
mesh_terms: D002384:Catalysis; D008872:Microwaves; D015394:Molecular Structure; D010165:Palladium / Q000737:chemistry; D011724:Pyridazines / Q000138:chemical synthesis* / Q000737:chemistry / Q000528:radiation effects*; D013237:Stereoisomerism
chemical_list: D011724:Pyridazines; D010165:Palladium