Tag: 15456-86-7

15456-86-7, 4-Bromo-1,2-dihydropyridazine-3,6-dione is a pyridazine compound, ?involved in a variety of chemical synthesis. Rlated chemical reaction is continuously updated,15456-86-7

b) 4-Bromo-3,6-dichloropyridazine A solution of 4-bromo-1,2-dihydropyridazine-3,6-dione (10 g, 52 mmol) in phosphorus oxychloride (100 ml) was stirred and heated at 100 C. under nitrogen for 16 hours. Upon cooling the excess phosphorus oxychloride was removed in vacuo. The residue was azeotroped with toluene (*2), then taken up in dichloromethane/water, The mixture was carefully basified with sodium hydrogen carbonate (solid). It was necessary to dilute the mixture further two get two clear layers. The two layers were separated and the aqueous was extracted with dichloromethane (*3). The combined extracts were dried (Na2SO4), filtered and evaporated. The residue was purified by chromatography on silica gel, eluding with dichloromethane to afford the title pyridaziyze (5.0 g, 42%) as a colourless solid. 1H NMR (250 MHz, CDCl3) 7.68 (br s). MS (ES+) 230 [MH]+, 228 [MH]+.

The synthetic route of 15456-86-7 has been constantly updated, and we look forward to future research findings.

Reference£º
Patent; Merck Sharp & Dohme Ltd.; US6319924; (2001); B1;,
Pyridazine – Wikipedia
Pyridazine | C4H4N2 – PubChem

With the rapid development and complex challenges of chemical substances, new drug synthesis pathways are usually the most effective.15456-86-7,4-Bromo-1,2-dihydropyridazine-3,6-dione,as a common compound, the synthetic route is as follows.

The solid in two batches was treated with phosphorus oxychloride (2×200 ml) and heated to reflux for 3.5 h. The mixture was cooled, evaporated and azeotroped with toluene. The residue was partitioned between dichloromethane and saturated aqueous sodium bicarbonate solution and extracted with DCM twice more. The organic extracts were dried and evaporated. This residue was re-dissolved in dichloromethane, and chromatographed on silica gel (300 g) (DCM as eluent) to give a white solid (101.5 g, 87%). (LC/MS analysis showed ca. 20-30% impurity, isomers of bromo- dichloropyridazine).MS (+ve ion electrospray) m/z 184/185/186 (MH+), trichloropyridazineMS (+ve ion electrospray) m/z 228/229/231 (MH+), bromo-dichloropyridazine.

The synthetic route of 15456-86-7 has been constantly updated, and we look forward to future research findings.

Reference£º
Patent; GLAXO GROUP LIMITED; WO2007/115947; (2007); A1;,
Pyridazine – Wikipedia
Pyridazine | C4H4N2 – PubChem

15456-86-7, 4-Bromo-1,2-dihydropyridazine-3,6-dione is a pyridazine compound, ?involved in a variety of chemical synthesis. Rlated chemical reaction is continuously updated

Preparation A; 6,7-Dihydro [1 ,4] dioxino [2,3-c] pyridazine-3-carbaldehyde; (a) 3,4,6-Trichloropyridazine; This was prepared by a slight variation on the method of Kasnar et al,Nucleosides & Nucleotides (1994), 13(1-3), 459-79.Hydrazine sulphate salt (51 g) was suspended in water (250ml), heated to reflux and bromomaleic anhydride (90.38 g) was added dropwise . The mixture was heated at reflux for 4 hours then cooled to room temperature. The reaction was repeated with 29g hydrazine sulphate, 53 g bromomaleic anhydride and 130ml water. The precipitates were collected by filtration, washed with water and acetone and dried as a combined batch in vacuo to afford 4-bromo-l,2-dihydro-3,6-pyridazinedione as a white solid (113 g).The solid in two batches was treated with phosphorus oxychloride (2×200 ml) and heated to reflux for 3.5 hours. The mixture was cooled, evaporated and azeotroped with toluene. The residue was partitioned between dichloromethane and saturated aqueous sodium bicarbonate solution and extracted with DCM twice more. The organic extracts were dried and evaporated. This residue was re-dissolved in dichloromethane, and chromatographed on silica gel (300 g) (DCM as eluent) to give a white solid (101.5 g, 87%). (LC/MS analysis showed ca 20-30% impurity, isomers of bromo-dichloropyridazine). MS (+ve ion electrospray) m/z 184/185/186 (MH+), trichloropyridazine. MS (+ve ion electrospray) m/z 228/229/231 (MH+), bromo-dichloropyridazine.

As the paragraph descriping shows that 15456-86-7 is playing an increasingly important role.

Reference£º
Patent; GLAXO GROUP LIMITED; WO2008/128942; (2008); A1;,
Pyridazine – Wikipedia
Pyridazine | C4H4N2 – PubChem