Triethylamine → 5-Methoxy-2-methyl-3(2H)-pyridazinone

A solution of 3.90 g (22.34 mmol) of 4-chloro-5-methoxy-2-methyl-2H-pyridazin-3-one and 3.74 ml (2.71 g, 26.8 mmol) of triethylamine in 60 ml of ethanol was hydrogenated at atmospheric pressure over 950 mg (0.894 mmol) of 10% palladium on charcoal for 20 h at 55° C. The suspension was filtered hot and the catalyst was washed three times with 10 ml of ethanol. The filtrate was concentrated in vaccuo, and the residue was taken up in 70 ml of methylene chloride, which was washed four times with 20 ml of water, dried over magnesium sulfate and concentrated to yield 2.79 g (19.9 mmol, 89%) of the title compound as a crystalline white solid, MS: 141.2 (M+H+).

1. filtrationThe suspension was filtered hot
2. washthe catalyst was washed three times with 10 ml of ethanol
3. concentrationThe filtrate was concentrated in vaccuo
4. washwhich was washed four times with 20 ml of water
5. dry with materialdried over magnesium sulfate
6. concentrationconcentrated

ORD record

ord-9d99dd7745044e75b281ceaaa467c6d7

Source dataset

uspto-grants-2012_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08334287B2