6-Phenyl-3(2H)-pyridazinone

19.6 g (162.95 mmol) of 1-phenylethanone and 5 g (54.32 mmol) of oxoacetate monohydrate were stirred at 100° C. for 2 hours. The reaction solution was then cooled to 40° C., and 20 ml of water and 4 ml of ammonia were added. The mixture was then twice extracted with 50 ml of dichloromethane. 2.64 ml (53.32 mmol) of hydrazine monohydrate were then added to the aqueous phase obtained, and the mixture was stirred at 100° C. for 2 hours. After the reaction, the reaction solution was cooled to room temperature. The precipitated crystals were filtered off with suction, washed with water and dried in a vacuum drying cabinet at 50° C. overnight. This gave 4.3 g (24.97 mmol, 15percent of theory) of the title compound as colorless crystals.LC-MS (method 7): RExample 41A6-Phenylpyridazin-3 (2H)-one 19.6 g (162.95 mmol) of 1-phenylethanone and 5 g (54.32 mmol) of oxoacetic acid monohydrate were stirred at 100° C. for 2 hours. The reaction solution was then cooled to 40° C., and 20 ml of water and 4 ml of ammonia were added. The mixture was then extracted twice with 50 ml of dichloromethane. 2.64 ml (53.32 mmol) of hydrazine monohydrate were then added to the aqueous phase, and the mixture was stirred at 100° C. for 2 hours. After the reaction, the reaction solution was cooled to room temperature. The precipitated crystals were filtered off with suction, washed with water and dried in a vacuum drying cabinet at 50° C. overnight. This gave 4.3 g (24.97 mmol, 15percent of theory) of the title compound as colorless crystals.LC-MS (Method 4): RPreparation of 6-Phenylpyridazin-3(2H)-one 5-3: (1197) (1198) A mixture of Cpd-5-1(1 g, 13.5 mmol) and 5-2 (4.88 g, 40.5 mmol) was heated at 110°C for 2h, cooled down to 40°C followed by addition of water (4.5 ml) and concentrated aqueous ammonia (1 ml). The reaction mixture was thereafter extracted with DCM, organic part was separated and the ammoniacal aqueous layer was treated with hydrazine hydrate (676 mg, 13.5mmol) followed by heating at 100°C for 2h, reaction mass cooled down to room temperature, precipitate formed was collected by filtration, residue dried under vaccum to afford 6-phenylpyridazin-3(2H)-one 5-3 (417 mg, 2.42 mmol, 17.9 percent) as an off-white solid. LC MS: ES+ 173.3

Molecular Weight:172.18
XLogP3:1.3
Hydrogen Bond Donor Count:1
Hydrogen Bond Acceptor Count:2
Rotatable Bond Count:1
Exact Mass:172.063662883
Monoisotopic Mass:172.063662883
Topological Polar Surface Area:41.5
Heavy Atom Count:13
Complexity:262
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes