Uses
6-Methylpyridazin-3(2H)-one is a lignin-based dye used on wool. It is also used as a reactant for the synthesis of C-(1-aryl-cyclohexyl)-methylamine derivatives as selective, orally available inhibitors of dipeptidyl peptidase IV, imidazopyridazinone derivatives as PDE7 inhibitors and pyridazinone derivatives with an arylpiperazinylalkyl chain as a potentent, orally active, antinociceptive agent.
Definition
ChEBI: 6-Methylpyridazin-3(2H)-one is a member of pyridazines.
Synthesis
General procedure for the synthesis of 6-methyl-3(2H)-pyridazinone from 4,5-dihydro-6-methylpyridazin-3(2H)-one: bromine (7.68 g, 48.05 mmol) was added slowly and dropwise to a solution of 6-methyl-4,5-dihydropyridazin-3(2H)-one (9.0 g, 80.26 mmol) in acetic acid (90 mL) at 90 °C. The reaction mixture was stirred continuously at 90 °C for 5-6 hours. Upon completion of the reaction, the excess acetic acid was removed by distillation under reduced pressure. The resulting residue was neutralized with aqueous sodium bicarbonate solution, followed by filtration to collect the solid product. The filter cake was dried to give the title compound 6-methyl-3(2H)-pyridazinone (6.0 g, 68% yield). The structure of the product was confirmed by 1H NMR (300 MHz, DMSO-d6): δ 12.73 (s, 1H), 7.30 (d, J = 9.6 Hz, 1H), 6.80 (d, J = 9.9 Hz, 1H), 2.14 (s, 3H).
References
[1] Bioorganic and Medicinal Chemistry Letters, 2012, vol. 22, # 19, p. 6286 - 6291
[2] Journal of Chemical Research, Miniprint, 1995, # 8, p. 1840 - 1852
[3] Journal of the Chemical Society, 1947, p. 239,242
[4] Patent: US4595521, 1986, A
